Using rice starch as raw material, starch stearate ester (SSE) was prepared by microwave-assisted method, and the SSE and its Pickering emulsion were characterized. The results showed that with the increase of stearic acid (SA) addition, the substitution degree of SSE first increased and then decreased, and the esterification reaction efficiency decreased first, then increased, and then decreased. With the increase of moisture content, the substitution degree and esterification efficiency increased first and then decreased. The effects of hydrochloric acid addition, microwave reaction time, and microwave power on the substitution degree and esterification efficiency were the same as moisture content. X-ray diffraction analysis showed that SSE still had an A-type crystalline structure. The three-phase contact angle of SSE particles increased with the increase of substitution degree. When the substitution degree was 0.0317, the contact angle was 89.6°, and SSE particles showed good oil-water amphiphilicity. The characteristics of Pickering emulsion constructed by SSE as emulsifier were studied, and the emulsification index, particle size and microstructure of the emulsion were analyzed. The results showed that when the addition of SSE was 2.5% and the volume of the oil phase was 60%, the emulsification index of Pickering emulsion was the highest, and the higher the substitution degree of SSE was, the smaller the particle size of the emulsion and the more stable the emulsion were. Particle size analysis and laser confocal microscopy observations showed that SSE could form a stable oil-in-water Pickering emulsion with a narrow droplet size distribution.

In order to prepare a more stable coconut oil emulsion, sodium caseinate (SC) and xanthan gum (XG) were combined as emulsifiers, and coconut oil was used as the oil phase, and the coconut oil emulsion was prepared by ultrasonic method. The average droplet sizes, Zeta-potentials, centrifugal stability and turbidity of emulsions were characterized to choose reasonable parameters concerning the ultrasonic treatment time, ultrasonic treatment power, mass fraction of oil phase, and pH values of aqueous phase, by the single factor test. The Box-Behnken response surface methodology (RSM) was used to optimize the parameter (including ultrasonic treatment power, ultrasonic treatment time, and pH values of aqueous phase) to prepare the stable emulsions. The optimal conditions were obtained as follows: Ultrasonic power 480 W, ultrasonic time 18 min, and pH7 of aqueous phase. Under this condition, the smallest droplets size of emulsions was obtained 304.5±13.2 nm. All coconut oil-based emulsions showed an extraordinary stability with heat treatment temperature of 40~90 ℃, pH6~8 and ion concentration of 0~0.5 mol/L, and the emulsion remained stable after three freeze-thaw cycles. The findings would provide a facile strategy to prepare stable coconut oil-based emulsions in the food processing.

Objective: To purify and characterize a water-soluble protein from Pueraria lobata and to fabricate its nanoparticles by heating-induced assembly. Methods: Pueraria lobata protein was purified by anion exchange chromatography High Q, and its molecular weight and amino acid sequence were determined by SDS-PAGE and N-terminal sequencing. The particle size, optical dispersion intensity and Zeta potential of protein nanoparticles were measured by laser-scattering particle analyzer. The drug loading efficiency of the nanocarrier was determined by chromatography. Results: A major water-soluble protein, named PP, was purified from Pueraria lobata and sequenced with a N-terminal amino acid sequence of DFVYDMCGNVLNGGTYYIL. PP was identified as a novel trypsin inhibitor by NCBI database searching and rypsin inhibitory assay. PP was also well-stabilized in the pH2~10 and 20~50 °C ranges. After heating PP solution (0.1 mg/mL, pH6.0) for 60 minutes at 100 ℃, homogenous nanoparticles (PP-NPs) were harvested. These PP-NPs had a particle size of 172.78 nm and a Zeta potential of −25.40 mV. The puerarin and berberine were effectively loaded onto PP-NPs, with loading efficiency of 33.83% and 24.61%, respectively. Conclusion: The major water-soluble Pueraria lobata protein PP can be fabricated into protein nanoparticles by heating-induced assembly, indicating a potential as drug carriers.

In order to improve the utilization rate of silver carp fat, a by-product of silver carp surimi processing, the modified starch-based Pickering emulsion was prepared with six modified starches as solid particles and silver carp oil as oil phase. The effects of starch type, starch amount (1%, 2%, 3%, 4%, 5%, w/w), oil-to-water ratio (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, w/w) and ionic strength (NaCl concentration: 0, 0.1, 0.2, 0.3, 0.4, 0.5 mol/L) on the emulsion physicochemical properties (including particle size, Zeta potential, emulsifying properties, stability, rheological properties, and microstructure) were investigated. The results showed that, among the six modified starches, the octenyl succinic anhydride modified corn starch had the smallest particle size (146.73 nm) and the largest contact angle (71.5°), and its Pickering emulsion had the best stability. The oil-water ratio and starch amount significantly affected the physiochemical properties of the prepared emulsion, and the emulsion had gel properties at the higher level of oil-water ratio (0.5~0.6) and starch amount (4%~5%). The addition of an appropriate amount (0.3~0.5 mol/L) of sodium chloride could promote the micro-flocculation of the emulsion and enhance the stability of the emulsion. The emulsion microstructure observed by confocal laser microscopic (CLSM) revealed that the particle size of the emulsion droplets decreased with the increase of starch amount, and the oil droplets were completely wrapped by modified starch particles and formed a dense interfacial film at the addition of 2%~5% starch. In conclusion, the better performance of Pickering emulsion was achieved at the oil-water ratio 0.5, starch amount 4% and sodium chloride concentration 0.4 mol/L, respectively. The study provides a reference for the preparation of fish oil Pickering emulsion and improves its application in functional food.

Nanostructured lipid carriers (NLC) for the encapsulation and protection of phytosterol (PS) were prepared using walnut oil as liquid lipid by high-pressure homogenization method. The average particle size, polydispersity index, Zeta potential and encapsulation efficiency were used as the main evaluation indexes to optimize the preparation process parameters and formulations, and the morphology and stability of the optimized PS-NLC were investigated. The optimal ratio for the preparation of PS-NLC was determined by orthogonal tests as 10% of total lipid concentration, 2:3 of stearic acid and walnut oil, and 1.2% of soy lecithin. The prepared PS-NLC had a spherical appearance, small particle size and uniform distribution. The stability results of PS-NLC showed that PS-NLC was stable in storage at 4 ℃ for 28 days. It was diluted 5~100 times with good dilution stability, when used. And the addition of 2% sucrose had the best effect on the lyophilization protection of PS-NLC. Walnut oil was used as the wall material of NLC to provide a suitable lipid delivery system for phytosterols, which could provide technical support for the construction of PS-NLC in food industry.

Objective: To assist the molding and curing of starch in 3D printing, and to reveal the change law of curing properties of different hydrocolloid-starch systems based on the phase-change characteristics of temperature-sensitive hydrocolloids. Methods: Three hydrocolloids, low-acyl gellan gum, gelatin, and κ-carrageenan, respectively, were mixed with corn starch at different ratios for evaluating their rheological properties. The printability and curing performance were evaluated by printing cylinder and hollow sphere models, testing force-displacement curves, temperature sweep rheology, whole-texture analysis and microstructure observation. Results: When gellan gum and κ-carrageenan were added at 2%~4% and gelatin at 0%~2%, the system had suitable rheological properties and good printability. The products with 4% gellan gum and 4% κ-carrageenan showed remarkable plasticity and better curing effect. Whereas the products with gelatin was not significantly plastic and cured. The curing temperature of gellan gum-starch system and κ-carrageenan-starch system were between 35~43 ℃ and 30~40 ℃ respectively, meanwhile, the curing temperature and speed increased with the increase of hydrocolloids content. However, as the gelatin content increased, the curing temperature decreased from 25 °C to 20 °C and the curing speed slowed down as well. The products with 4% low-acyl gellan gum had a denser gel network, which was harder than that with 4% κ-carrageenan. Gelatin weakened the hardness and elasticity, but greatly increased the adhesion. Conclusion: Appropriate low-acyl gellan gum and κ-carrageenan contributed to the molding and curing of starch, and the curing performance of κ-carrageenan was better than that of gellan gum, while gelatin had no auxiliary curing ability.

The effects of different heat treatment temperatures (75, 80, 85, 90, 95 ℃) on the embedding rate, particle size, zeta, secondary structure, tertiary structure and its digestibility in vitro of soybean protein isolate-curcumin complexes were studied in order to explore the structure and interaction mechanism of complexes. The results showed that heat treatment at 85 ℃ was the best to combine soybean protein isolate with curcumin. Meanwhile, the embedding rate reached 89.13%, the particle size was 163.33 nm, and the potential value was −24.30 mV. The total sulfhydryl group and surface hydrophobicity of complex reached the maximum, 3.82 μmol/g and 3814±20, which indicated that the protein structure was stretch to stable and interact with curcumin to improve the digestibility in vitro. It was also concluded that the binding effect of soybean protein isolate and curcumin was enhanced by heat treatment. The result would be beneficial to the innovation and development of soybean protein isolate and curcumin complex.

Distiller's grains are the major by-product in spirits industry. Baijiu distiller's grains after fermentation and distillation are rich in prolamin. However, the poor water solubility of prolamin from distiller's grains (PDG) limits its further application. In this work, PDG was extracted by ethanol-alkali method and phosphorylated with sodium tripolyphosphate (STP). Furthermore, the effect of phosphorylation on the functional properties of PDG was evaluated by water solubility, water holding capacity, oil holding capacity and emulsion capacity. The results showed that PDG extracted by ethanol-alkali method was mainly composed of four proteins with different molecular weights. The extraction rate of PDG was affected by the crushing degree of distiller’s grains powder, and small particle size was conductive to improve the protein extraction rate. The extraction rate of PDG reached 22.69%±0.26% when the powder was 200 mesh. The differential scanning calorimeter results indicated that PDG possessed good thermostability with the denaturation temperature of 123.47 ℃. Fourier transform infrared spectrometer (FTIR) results showed that PDG was modified with phosphate groups after reaction with STP. The water solubility of PDG after phosphorylation was improved and it was 3.53 times higher than that of PDG, reaching 943.08±16.04 μg/mL at 30 ℃. Due to the combination of phosphate groups, the functional properties of PDG were significantly improved. Compared with PDG, the water holding capacity and oil holding capacity of phosphorylated PDG at 30 ℃ were increased by 44.9% and 33.8% respectively, and the emulsifying property and emulsifying stability at pH10 were increased by 54.9% and 3.6 times respectively. The improvement of the functional properties was conductive to the expansion of PDG's application fields. This work laid a foundation for the high added-value utilization of distiller's grains.

In this study, goat milk was sterilized under different conditions (65 ℃, 30 min; 75 ℃, 20 min; 85 ℃, 15 min; 90 ℃, 10 min). The chromaticity, appearance, flavor and content of medium-short chain free fatty acids of goat milk were determined by chromaticity analyzer, electronic nose analysis, high performance gas chromatography and ultra-high resolution microscope, and the changes of average particle size and microstructure of goat milk were investigated during 21 days of storage. The results showed that different sterilization conditions had no significant effect on the color and appearance of goat milk (P>0.05). Electronic nose detection could obviously distinguish the flavor changes of goat milk under different sterilization conditions, and the contents of medium-short chain free fatty acids in milk were significantly increased after sterilization (P<0.05). After 21 days of storage, the increase of goat milk particle size led to the decrease of system stability. The sterilization condition of 90 ℃ and 10 min could effectively inhibit the increase of goat milk particle size during storage, which would be beneficial to improve the stability of goat milk and provide theoretical basis for enhancing the quality characteristics of goat milk and improving its processing technology.

Quinoa flour was subjected to dry heat treatment at room temperature (for control), 110, 130 and 150 ℃ for 1 h, respectively, and different treatments quinoa flour 15% and wheat flour 85% (w/w) were mixed to make bread, the effects of dry heat treatment temperature on the structure of quinoa flour, powder properties and tensile properties of the mixed flour dough as well as textural properties and in vitro digestive activity of the bread were analyzed. The results showed that the dry heat treatment caused the shedding of aggregates on the quinoa flour particles surface and caused defects, meanwhile the shedding degree of aggregates increased with the increase of treatment temperature. While, the crystal type of quinoa flour was not change and remained A-type after dry heat treatment. Compared with control, the water absorption and weakness of the dough that added quinoa flour treated with 110, 130 and 150 ℃ increased by 1.79% and 43.75%, 3.25% and 104.17%, 4.83% and 125.00%, respectively. Elongation, maximum tensile resistance and tensile resistance decreased gradually, and the tensile ratio increased first and then decreased. In addition, the bread hardness decreased by 1.82% and elasticity increased by 4.51% at 110 °C, while the other treatments increased the hardness and decreased the elasticity of quinoa-bread. Meanwhile, the dry heat treatment significantly decreased the RDS content and increased the SDS and RS content of quinoa-bread (P<0.05). This study can provide a theoretical basis for the development of functional foods from quinoa flour.

Three drying methods, including natural air drying, hot air drying, and heat pump drying were studied in this paper to meet the different needs for the industrial production of Chinese bacon. The principal components analysis (PCA) on the physical and chemical indicators was conducted by comparing water activities, moisture contents, yield ratios, acid values, peroxide values, hues, organoleptic attributes, and textures. The results indicated that the Chinese bacon obtained by natural air drying had poor color quality, while the Chinese bacon obtained by hot air drying had the highest acid value, peroxide value, and yield ratio. In addition, the Chinese bacon obtained by heat pump drying had the lowest water activity, lowest moisture content, best color quality, highest sensory score, lowest hardness, and fastest drying rate. Its water activity was 0.718, the moisture content was 18.13 g/100 g, the yield ratio was 62.20%, the peroxide value was 0.127 g/100 g, the acid value was 0.83 mg/g, the color deviation was 12.28, the sensory score was 39.50, and the hardness was 8120.16 g. By PCA, the first two principal components were extracted, and the cumulative contribution rate reached 100%. Furthermore, the water activity, moisture content, peroxide value, hardness, springiness, gumminess and chewiness contributed to the first principal component, while the yield ratio, acid value, color deviation, and resilience contributed to the second principal component. In summary, the best quality of Chinese bacon products can be obtained by heat pump drying, which can provide a theoretical basis for the industrial production of meat products.

In this study, epigallocatechin gallate (EGCG)/curcumin (Cur) composite liposomes (EGCG/Cur-L) were prepared by thin-film hydrophoresis, and the optimal preparation process was determined by single-factor test. To increase the stability of liposomes, the surface of the composite liposomes was modified with distearoyl phosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG₂₀₀₀), and the encapsulation rate, particle size distribution, micromorphology, and modification effect of both liposomes were investigated, and the oxidative stability of liposomes was evaluated by DPPH method. The results showed that the optimal process for the composite liposomes was: Lecithin to cholesterol mass ratio of 6:1, PBS buffer solution pH of 6.5, EGCG added amount 6 mg, Cur added amount 3 mg, and hydration temperature of 55 ℃. The encapsulation rate of EGCG was 68.78%, the encapsulation rate of Cur was 90.23%, the average particle size was 183.8±5.4 nm, the polydispersity coefficient (PDI) was 0.178±0.01, and the average Zeta-potential was −34.7±0.62 mV. The encapsulation rate of EGCG after modification was 60.31%, and the encapsulation rate of Cur was 88.53%. After surface modification, the encapsulation rate of Cur did not change significantly, and the encapsulation rate of EGCG decreased, dynamic light scattering (DLS) and transmission electron microscopy (TEM) results showed that the average particle size of the modified liposomes increased from the unmodified 183.8 nm to 374.5 nm, Zeta-potential and Fourier infrared analysis indicated that DSPE-PEG₂₀₀₀ was successfully modified on the liposome surface and did not change the internal structure of the liposomes. The modified liposomes had the highest DPPH scavenging rate and all had greater oxidative stability than other liposomes within 15 days, indicating that DSPE-PEG₂₀₀₀ could enhance the antioxidant capacity of liposomes.

To explore the effect of Caragana korshinskii Kom. (CK) on meat quality and the main fatty acids of adipose tissue, which were supposed to be modulated by the level of volatile fatty acids from the microbiota of rumen and colon in sheep, twelve Tan ewe lambs (4-month-old) were randomly divided into two groups, NC was fed with 30% concentrate and 70% alfalfa, while CK with 10% CK instead of equivalent alfalfa. After 10 days of pre-trial and 60 days of feeding trial, the lambs were slaughtered and sampled with M. longissimus dorsi, quadriceps femoris, subcutaneous fat, and the contents of rumen and colon collection. Then the analyzing was carried out aimed to determine the characters of meat physical and chemical properties as usual method, the microbiota of gastrointestinal tract by 16S rRNA sequencing, and fatty acid contents either from subcutaneous adipose tissue or from rumen and colon by gas chromatography-mass spectrometry. The results showed that feeding CK to Tan sheep could tend to increase mill loss, decrease water holding capacity and cooked meat percentage of quadriceps femoris. It also had the tendency effect to decrease saturated fatty acid and increase unsaturated fatty acid content in the meat. Furthermore, feeding CK could decrease the content of palmitic acid in subcutaneous adipose tissue significantly (P<0.05). Besides, the concentrations of butyric acid in rumen and acetic acid in colon decreased significantly (P<0.05), while the levels of branched chain fatty acids such as iso-butyric acid and iso-valeric acid in colon increased significantly (P<0.01). Through correlation analysis by Spearman method, both 5-7N15 and YRC22 in rumen genera tended to positively correlated with butyric acid concentration, while Treponema in colon genera tended to positively correlated with acetic acid content, but negatively correlated with the level of iso-butyric acid (0.05<P<0.1). In colon, iso-butyric acid was high inversely and positively correlated with the cooked meat percentage, water holding capacity and mill loss of quadriceps femoris, and acetic acid was negatively correlated with the pH value of M. longissimus dorsi. In conclusion, feeding CK to Tan sheep with partly instead of alfalfa could improve unsaturated fatty acid contents of adipose tissue, and then it could be developed as ruminant forage for utilization.

To improve the quality of brine goose pre-products, the following treatment groups were set up in the experiment: Tumbling ultrasonic compound marination method (G+C treatment group), tumbling marination method (G treatment group), ultrasonic marination method (C treatment group), tumbling marination method with salt (G+NaCl treatment group), and conventional wet marination method (conventional treatment group) to investigate the effects of ultrasonic treatment and tumbling treatment on the quality of brine goose pre-products with meat color, water holding capacity, fat oxidation value, texture, sensory evaluation, microstructure, and fatty acid as evaluation indexes. The results showed that the G+NaCl treated group had bright meat color and the best water holding capacity. The conventional treatment group had the lowest TBARS value, and the fat oxidation in the other treatment groups after tumbling and ultrasonic treatment was higher than that of the conventional treatment group. The results of sensory evaluation and texture showed that the elasticity and chewiness of the G+NaCl treated group were the best. A total of eight fatty acids were detected in each treatment group, two saturated fatty acids (SFA), six unsaturated fatty acids (UFA), three monounsaturated fatty acids (MUFA), and three polyunsaturated fatty acids (PUFA) each. The total fatty acids of the C treatment group, G+NaCl treatment group and G+C treatment group were similar, and the total fatty acids of G+C were the smallest. In conclusion, the G+NaCl treatment group was the optimal group.

In the presence of blueberry anthocyanins (ACNs), chitosan hydrogel crosslinking with salicylaldehyde (ACNs/CS-SA) was constructed. The structure and morphology of ACNs/CS-SA were characterized. The stability, swelling properties and ACNs controlled-release behaviors for the ACNs/CS-SA were investigated in the media of different pH. ACNs were uniformly dispersed in three-dimensional network structure of CS-SA hydrogel by physical embedding, which was confirmed by FT-IR and XRD characterization. The thermal stability of ACNs was significantly improved due to gelation, which was confirmed by TG-DTG characterization. Both the swelling properties and ACNs controlled-release behaviors for the ACNs/CS-SA exhibited pH response. In buffer media of pH2.7, 4.6 and 6.7, the cumulative release rates of ACNs for 24 h were 74.28%±4.58%, 40.72%±4.04% and 15.70%±1.71%, and the release process followed Weibull equation with the correlation coefficients R² 0.99405, 0.95165 and 0.99712, respectively. This study lays a theoretical and experimental foundation for the development of novel drug encapsulation materials and the application of ACNs owing to the ACNs/CS-SA pH responsiveness and ACNs thermal stability improvement.

Enzymatic modification can effectively improve the gel property of soybean protein. In order to study the effect of transglutaminase (TGase) pre-crosslinking on the properties of salt induced soy protein isolate (SPI) gel, SPI dispersions with different crosslinking degree were prepared by controlling the enzyme concentration and the pre-crosslinking time, and their gelation properties under the action of CaSO₄ were studied. The results showed that compared with SPI without TGase treatment, appropriate pre-crosslinking of protein could significantly improve the quality of SPI gels. After 3~5 U/g TGase crosslinking for 20 min or 3 U/g TGase crosslinking for 20~30 min, the properties of SPI gel were improved to different degrees, among which the elastic modulus, yield stress, yield strain and water holding capacity were increased by 124.6%, 269.0%, 135.0% and 53.0%, respectively. However, excessive crosslinking produced protein aggregates with too large size, resulting in coarse and porous gel structure and significantly decreased (P<0.05) in gel strength and water holding capacity. It can be seen that proper utilization of TGase can improve the quality of SPI gel products, which has important guiding significance for the application of TGase in food industry and the improvement of texture of traditional soybean products.

In order to improve the utilization of agricultural and forestry waste and promote the industrial production of new biomass materials, sorghum straw powder (SSP), nano-ZnO, polyvinyl alcohol (PVA) were used as the main film matrix and sorghum straw powder/nano-ZnO/polyvinyl alcohol (SSP/Nano-ZnO/PVA, SNP) nanocomposite films were prepared by blending casting method in this research. The effects of SSP addition and different film-forming temperatures (75, 80, 85, 90, 95 ℃) on the thickness, tensile strength (TS), barrier properties, microstructure, spectral properties and thermal properties of SNP nanocomposite films were investigated. The results showed that the addition of SSP could improve the TS, barrier properties and thermal properties of the SNP nanocomposite films. With the increase of the film-forming temperature, the TS and barrier properties of the SNP nanocomposite films increased first and decreased later. When the film forming temperature was 85 ℃, SNP nanocomposite film exhibited the best comprehensive performance with maximum TS (31.22 MPa) and minimum water vapor transmission coefficient (1.32×10⁻¹² g/(cm·s·Pa)), water soluble (36.41%) and swelling degree (238.41%). The SEM, AFM, FT-IR and TG analyses showed that the SNP nanocomposite film had a smooth surface, dense cross-section, good compatibility between the substrates and good thermal stability, and overall performance (better than other film-forming temperatures of nanocomposite films).

In order to study the bactericidal mechanism of slightly acidic electrolyzed water (SAEW) against Salmonella enteritidis, the effects of SAEW on cell membrane permeability, cell membrane integrity, reactive oxygen species (ROS), and intracellular ATP of Salmonella enteritidis were studied. The results showed that 2.04 lg (CFU/g) of Salmonella enteritidis on the surface of eggshells was inactivated after the SAEW treatment at the available chlorine concentration of 10 mg/L for 1 min. Moreover, relative to the control group, the conductivity of bacterial suspension of Salmonella enteritidis was increased from 13.78±0.13 ms/cm to 16.32±0.10 ms/cm (P<0.05) in the SAEW group. In addition, the protein leakage in the bacterial cells was significantly increased from 0.07±0.04 g prot/L to 0.30±0.03 g prot/L (P<0.05). Moreover, the SAEW treatment increased the nucleic acid leakage and ROS accumulation and the intracellular ATP content reduction. The result of SEM also showed that, after the SAEW treatment, the cell wall structure of Salmonella enteritidis was incomplete, damaged and obviously perforated, and many bacterial surfaces were sunken, deformed or broken and adhered. The results showed that SAEW significantly increased the permeability and seriously destroyed the integrity of the cell membranes of Salmonella enteritidis, which led to the leakage of intracellular proteins, nucleic acids, ATP and other contents, leading to the accumulation of ROS.

The bacterial community structure and diversity of eight sour porridge samples collected from Ordos, Inner Mongolia were studied by Illumina Miseq high-throughput sequencing technology, and the dominant strains were isolated and identified. The results showed that the bacteria in the eight samples mainly belonged to Firmicutes and Proteobacteria. Lactobacillus and Acetobacter were the dominant genera. Lactobacillus was the highest abundance genus in all samples accounting for 42.63% to 97.49%. The structures of bacterial community in SZ1 and SZ2 differed from those in other samples, which was probably related to different sampling time. One strain was identified as Lactobacillus casei, one strain was identified as Lactobacillus fermentum, two strains were identified as Lactobacillus plantarum and four strains were identified as Lactobacillus paracasei by physiological and biochemical experiments as well as molecular biological method. The above research results provide strain resources and theoretical basis for the industrialized production of sour porridge.

Litsea cubeba essential oil is a pure natural plant essential oil. In this paper, the inhibitory effect of Litsea cubeba essential oil on the growth, metabolism and toxin production of Aspergillus flavus was investigated. In this study, peanuts were placed in a natural environment to infect bacteria, and the target bacteria were isolated and purified. Morphology and ITS sequence methods were used to classify and identify the strains. The inhibition ability of essential oil on Aspergillus flavus was discussed by the determination of inhibition zone, inhibition rate and minimum inhibitory concentration (MIC). The effects of essential oil on the germination rate, growth curve and aflatoxin B1 production of Aspergillus flavus, as well as the effects of cell membrane permeability and cellular enzyme activity, were tested. The results showed that strain HB₂ was isolated and screened from spoilage peanuts and was identified as Aspergillus flavus by the ITS sequence method. The results of aflatoxin determination showed that aflatoxin B1 (AFB1) had a mass concentration of 3.4×10³ μg·kg⁻¹ (pure wet bacteria). The bacteriostatic zone significantly increased with increasing essential oil concentration, and the minimum inhibitory concentration (MIC) for Aspergillus flavus was 0.800 μL·mL⁻¹. The germination rate, the length of the dental tube, the growth of Aspergillus flavus, and the concentration of AFB1 showed a significant decreasing trend with increasing concentrations of essential oil in the culture medium. When the concentration of Litsea cubeba essential oil was 0.100 μL·mL⁻¹, the growth of the bacteria was invisible to the naked eye. With the increase in the concentration of essential oil, the conductivity of the culture medium increased, the utilization rate of reducing sugars and the protein content of the bacteria decreased, and the activities of malate dehydrogenase and succinate dehydrogenase in the bacteria decreased. These results indicated that Litsea cubeba essential oil caused irreversible damage to Aspergillus flavus. It is speculated that Litsea cubeba essential oil damaging the cell wall and cell membrane, affecting cell growth and metabolism and ultimately leading to cell death. Therefore, Litsea cubeba essential oil has a good inhibitory effect on Aspergillus flavus and can be widely used in grain storage and food antimolding.

In this study, Jinta and Yanhong chilli peppers from Shandong Province were selected in order to explore the changes of bacterial community and quality of chilli peppers during salting process. Eleven indicators of bacterial community, titratable acid, pH, moisture content, water activity, sodium chloride, reducing sugars, spiciness, organic acids, nucleotides and amino acid nitrogen were monitored in samples of Jinta and Yanhong chilli peppers within 12 weeks during salting. The results showed that the third week of salting of the two kinds of chilli peppers was the inflection point of bacterial dynamic change. Before that, the number of salting beneficial bacteria such as Weisseria spp. and Lactobacillus spp. was high, and after that, the number of Enterobacter spp. increased, possibly because the two peppers were not fermented enough to inhibit the growth of Enterobacter spp.. The fourth week of salting of the two kinds of chilli peppers was the inflection point of quality and flavor change. Before that, the levels of reducing sugars, lactic acid, acetic acid, nucleotides and amino acid nitrogen, which gave good flavour to the salted chilli peppers, were high and the sodium chloride levels were appropriate. Therefore, the optimum salting time for the Jinta and Yanhong chilli peppers was 3 to 4 weeks. And the water activity and the moisture content determine the degree of salting. The water activity and moisture content of Jinta salted chilli pepper were stable at about 0.80 and 69.3%, respectively, which were higher than those of Yanhong salted chilli pepper at 0.78 and 63.5%, so it was speculated that Jinta salted chilli pepper had a higher fermentation degree. This study provided data and technical support for the production optimization of salted chilli pepper processing enterprises and theoretical support for the promotion of high-quality development of salted chilli pepper products.

Aflatoxin B₁ (AFB₁) is a type of fungaltoxin with strong toxicity and strong carcinogenicity. To screen degrading bacteria of AFB₁, co-culture of fungi strains which were stored in laboratory and AFB₁ was carried out and the strains with the highest degradation rate were chosen. Species of the chosen strains were determined through morphology and ITS rDNA analysis. After separation of different components (bacterial suspension, thalli, spore suspension and fermentation liquor) in strains, the effective components for AFB₁ degradation were explored, and the effective components thalli was broken for further investigation. Results showed that the AFB₁ degrading rates by Penicillium herquei MD1 bacterial suspension cultured by 72 h and the unbroken thalli were 98.15% and 28.20%, respectively. The degradation of AFB₁ was better after the fragmentation of the thalli, and the degradation rate of AFB₁ was 55.40% after 24 h of incubation. Therefore, the active components in MD1 bacterial suspension and thalli can degrade AFB₁ effectively. The screened MD1 expands the degrading bacterial library of AFB₁ and provide some references to biological degradation of AFB₁.

Objective: To optimize the cellulase extraction process of crude polysaccharide from Semen Cassiae and study its antioxidant activity in vitro. Methods: On the basis of single factor test results, Box-Behnken response surface methodology was used to optimize the extraction process of crude polysaccharide from Semen Cassiae with enzymolysis time, enzymolysis temperature, enzyme dosage, liquid-to-material ratio and enzymolysis pH as independent variables, and the yield of polysaccharide as response value. DPPH radical and hydroxyl radical scavenging rates were used to investigate the antioxidant activities of crude polysaccharides from Semen Cassiae in vitro. Results: The optimal cellulase extraction conditions of crude polysaccharide from Semen Cassiae were as follows: Enzyme dosage was 1.4%, enzymolysis time was 50 min, liquid-to-material ratio was 24:1 mL/g, enzymolysis pH was 5.4, and enzymolysis temperature was 48 ℃. Under these conditions, the yield of polysaccharide from Semen Cassiae was 11.67%, and the theoretical prediction value of regression model was 11.91%, the error between the two conditions was less than 5%. Crude polysaccharide from Semen Cassiae had strong scavenging effects on DPPH free radical and hydroxyl free radical, with median inhibitory concentrations of 1.025 mg/mL and 0.894 mg/mL, respectively. Conclusion: Cellulase enzymatic method can significantly improve the yield of crude polysaccharide from Semen Cassiae, the process is simple and feasible, and the crude polysaccharide obtained from Semen Cassiae has antioxidant activity in vitro.

Using cowhide as raw material, the process of ultrasonic-assisted enzyme extraction of collagen from cowhide was optimized. Based on the single factor experiment, a response surface test was designed, and the extraction rate of cowhide collagen was used as the response value to optimize the optimal extraction process of collagen, and its structure was characterized. The results showed that the optimal extraction conditions of collagen from cowhide were ultrasonic power 161 W, ultrasonic treatment time 64 min, pepsin addition 109 U/g, and solid-liquid ratio 1:16 g/mL. Under these conditions, the extraction rate of collagen was 63.77%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), ultraviolet spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) analysis showed that the collagen extracted by ultrasound-assisted enzyme was in line with the characteristics of type I collagen, maintaining its complete triple helix structure, amino acid composition and scanning electron microscope (SEM) analysis showed that the collagen triple helix extracted by ultrasonic assisted enzyme was relatively stable. In this study, an effective process is optimized for the extraction of collagen from cowhide, besides, the extraction time of collagen is greatly shortened and it has high utilization value.

Discarded eggshells and wet soybean dregs are rich sources of calcium and nitrogen. This study aimed to establish a novel optimized method for the utilization of agricultural wastes. Eggshells and soybean dregs were the primary raw materials used in this study. Bacillus subtilis, Lactobacillus plantarum, and Enterococcus faecalis were the probiotic strains selected for mixed fermentation. Harman’s single-factor test based on the assessment of calcium lactate content in the fermented forage was used to screen the following process parameters: Ratio of soybean dregs to eggshells, solid to water ratio, addition of glucose, inoculation amount, ratio of probiotic strains, fermentation temperature and duration. Optimum fermentation conditions were determined using response surface methodology. The results revealed that the conditions required for optimum fermentation were as follows: Soybean dregs to eggshells ratio of 90:10, solid to water ratio of 1:2.5, addition of 15.6% glucose, inoculation amount of 14.7%, Bacillus subtilis, Lactobacillus plantarum and Enterococcus faecalis in the ratio of 1:1:1 (v/v), and fermentation duration of 6 days at 37 °C. The amount of calcium lactate in the fermented forage was 13.58%. Free amino acid and calcium lactate concentrations in the fermented forage were significantly higher (P<0.05) in comparison to their concentrations in the raw materials. A significant decrease in pH and concentrations of crude fat and soluble protein in the fermented forage was also observed (P<0.05). In conclusion, this study established a novel optimized method for the production of high calcium feed from eggshells and soybean dregs using probiotic fermentation.

In this study, blueberry pulp was used as the material to promote the release of bound polyphenols into free polyphenols by enzymatic transformation. The antioxidant activities of different forms of polyphenols were investigated. With the conversion rate of free polyphenols as the index, the optimal combination of different enzymes was screened. The single-factor test and the Box-Behnken response surface test were used to determine the optimal enzymatic hydrolysis parameters. The antioxidant activity was measured by FRAP and ABTS assays. The results showed that the optimal enzymatic hydrolysis conditions were as follows: Complex enzyme was composed of pectinase and cellulase with a ratio of 4:6, the dosage of complex enzyme was 2.8%, the hydrolysis temperature was 50 ℃, and the hydrolysis time was 124 min. Compared with the control group, the conversion rate of free polyphenols in enzymatic blueberry pulp was 83.47%, which was increased by 9.96%. The content of free polyphenols in enzymatic blueberry pulp (343.58 mg GAE/100 g FW) was increased by 27.67%, and the content of bound polyphenols (68.03 mg GAE/100 g FW) was decreased by 29.84%. The results of antioxidant activity revealed that the FRAP and ABTS antioxidant capacity of free polyphenols extract in enzymatic blueberry pulp was elevated by 15.45% and 27.25%, respectively. The FRAP and ABTS antioxidant capacity of total polyphenols in enzymatic blueberry pulp was increased by 6.81% and 15.62%, respectively. These results indicates that enzymatic hydrolysis promotes the transformation of free polyphenols in blueberry pulp and enhanced the antioxidant capacity of blueberry pulp, which provides a theoretical basis for the development and processing of functional activity for blueberry products.

With black garlic, tea tree mushroom and millet pepper as the main raw materials, sensory evaluation as the standard, single factor experiment, fuzzy mathematical evaluation and response surface optimization were used to optimize the factors affecting black garlic tea tree mushroom sauce, such as tea tree mushroom, millet pepper, vegetable oil, edible salt, white sugar, starch, onion, ginger and garlic. A black garlic sauce product was studied and its antioxidant activity was compared with the commercially available Chunjiuyuan tea tree mushroom sauce. The results showed that the best preparation formula of black garlic tea tree mushroom sauce was: 20 g black garlic, 18.05 g tea tree mushroom, 3.49 g millet pepper, 6.96 g vegetable oil, 3.48 g salt, 1.16 g white sugar, 2.32 g starch, 1.16 g onion, ginger and garlic respectively, and the sensory score was 88.26 points. Black garlic tea tree mushroom sauce and Chunjiuyuan tea tree mushroom sauce had scavenging capacity for DPPH free radical, hydroxyl radical, superoxide anion radical, and reducing capacity for Fe³⁺, which had a positive dose effect relationship with the volume concentration. However, the scavenging capacity and reducing capacity of black garlic tea tree mushroom sauce were better than those of Chunjiuyuan tea tree mushroom sauce. When the volume concentration reached 1 mL/mL, the scavenging capacity of DPPH free radical, hydroxyl radical and superoxide anion radical were 93.6%, 75.9% and 50.8% respectively, and the reduction capacity of Fe³⁺ was also the largest, indicating that the prepared black garlic tea mushroom sauce had good antioxidant properties. The results of physicochemical and microbial indexes showed that the water content was 52.35 g/100 g, the total acid content was 2.02 g/kg, the total number of colonies was 816.6 CFU/mL, the nitrite content was 2.53 mg/kg, coliforms were not detected. The above indicators were in line with the relevant national requirements of GB 31644-2018 National food safety standard compound seasoning. Under this condition, black garlic tea tree mushroom sauce has mellow flavor, bright luster and moderate viscosity, providing data reference for the development of black garlic tea tree mushroom sauce.

Wine mud is the precipitate produced during fermentation and storage, which contains pectin, protein, polyphenols and other substances. To realize the value-added utilization by separating and extracting the effective components of the mud in white wine production, in this study, the effects of material-liquid ratio, pH, extraction temperature and extraction time on the yield of pectin were investigated by the single-factor test, the extraction condition was optimized by the response surface method, the decolorization of pectin was carried out using macroporous resin, and the structure was characterized by infrared spectroscopy and HNMR. The results showed that the yield of pectin was 6.48% on the condition of wine mud:water=1:14 g/mL, pH was 2.0, extraction temperature was 65 ℃ and extraction time was 90 min, which was near to the predicted value of 6.50% by the response surface model. The factors on the yield followed as material-liquid ratio>extraction temperature>extraction time>pH. Decolorized by D101 macroporous resin under the condition that decolorization temperature was 25 ℃, pH was 2.0, decolorization flow rate was 3 BV/h and desorption solution was 60% (v/v) ethanol, desorption flow rate was 3 BV/h, the decolorization rate could reach 91.75%. IR and HNMR analysis showed that pectin extracted was α-galacturonic acid. This study would provide a reference for the separation and utilization of wine mud.

To explore the process of extraction and antioxidant activity of products from marine sponge, three influencing factors, ultrasonic temperature, ultrasonic time, and ultrasonic power were investigated respectively taking DPPH radicals scavenging rate of ethanol extracts from H. erectus as the response value, and the optimal ultrasonic-assisted extraction process was determined by Box-Behnken design. The extract obtained from H. erectus by the best ultrasonic-assisted process was detected for antioxidant activity, which included the scavenging effect on DPPH radicals, ABTS⁺• and •OH. The effects of the extract on viability of oxidative damage L02 cells and content of intracellular ROS were detected by constructing a cell model of H₂O₂ induced oxidative damage. The results showed that the optimized process conditions were as follows: Ultrasonic temperature was 57 ℃, ultrasonic time was 60 min, and ultrasonic power was 490 W. Under these conditions, the DPPH scavenging rate of the extract was 61.98%±1.52%, which agreed well with the predicted value of 62.16%. The extract showed good scavenging effects on DPPH radical, ABTS⁺• and •OH. The cell viability of treated groups was significantly higher than that of the model group (P<0.05), and the intensity of intracellular ROS fluorescence was significantly lower than that of the model group (P<0.01). In general, the product from H. erectus had a wide range of antioxidant activity, and it had a protective effect on H₂O₂ induced oxidative damage in L02 cells. This study provides theoretical support for the research and development of antioxidant food additives.

Objective: Ruditapes philippinarum was used as raw material to investigate the preparation process of peptide and its enhanced immunomodulatory effect. Methods: The hydrolysis degree of protein was used as an evaluation index to screen the optimal protease. The single factor experiment and response surface test were used to determine the best enzymatic hydrolysis condition. The amino acid composition was analyzed using amino acid analyzer. And organ/body weight ratio, spleen lymphocyte transformation test, serum hemolysin experiment, peritoneal macrophage swallowing chicken red blood cell test, and NK cell activation experiment were used to assess the clam peptide enhanced immune activity. Results: Trypsin was the most suitable protease in the preparation of protein peptides from Ruditapes philippinarum. The optimal enzymatic conditions were temperature 48.4 ℃, pH8.0, enzyme concentration 3795 U/g, solid-liquid ratio 1:2, and hydrolysis time 4 hours. The average molecular weight of protein-peptide was 418 Da with 15.33% hydrolysis degree under optimal enzymatic conditions. The amino acid composition of the clam peptide was reasonable and the proportion of essential amino acids reached 41.48%. The organ ratio of BALB/c mice did not change significantly as compared to the control group after receiving various doses of oral clam peptides for 30 days. Furthermore, the serum hemolysin levels were significantly (P<0.05) increased of low dose (700 mg/(kg·d)) and high dose (2800 mg/(kg·d)) groups and the phagocytic rate of peritoneal macrophage swallowing chicken red blood cells was significantly (P<0.01) increased of low dose (700 mg/(kg·d)) and middle dose (1400 mg/(kg·d)) groups, which indicated the enhanced immunomodulatory effect of the clam peptide. Conclusions: The clam peptide produced using this process shows a high degree of hydrolysis, a low molecular weight, and a concentrated distribution with enhanced immune function. It has the potential to produce healthy foods or foods for special dietary uses.

In order to obtain a kind of Lonicera japonica leaves herbal tea with strong antioxidant activity and high health care, an orthogonal array design based on single factor experiments was employed to examine the influence of time, temperature, inoculum amount of L. plantarum 758 and the concentration of sugar (The mass ratio of glucose to sucrose was 3:2) on the fermentation process. The antioxidant and volatile components of Lonicera japonica leaves herbal tea were compared with those of three common herbal tea in the market. Results showed that the optimal fermentation conditions were determined as fermentation of Lonicera japonica leaves extract containing 7% sugar added at 38 ℃ for 24 h with an inoculum amount of 4%. Under these conditions, the chlorogenic acid content of Lonicera japonica leaves herbal tea reached 7.11%, the total flavonoids content was 22.51%, the DPPH free radical clearance rate was 84.23%±3.32%, and the ABTS free radical clearance rate was 85.30%±2.14%, which were significantly higher than those of the three kinds of herbal tea on the market (P<0.05). There were 32 kinds of volatile substances in Lonicera japonica leaves herbal tea, and their types and contents were higher than those in other comparison groups. Overall, the antioxidant capacity of Lonicera japonica leaves herbal tea fermented by L.plantarum 758 is outstanding, and it has higher nutritional value and practical function.

In order to evaluate the harm of pesticide residues and explore the high-risk hazard factors and risk levels in different varieties of Xinjiang red jujube (winter jujube, Hui jujube and Jun jujube), 93 pesticides were determined by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. The differences of pesticide residues in different varieties of jujube were compared, and the risk of pesticide residues in jujube samples were evaluated and ranked. A total of 16 kinds of pesticides were detected in 85 red jujube samples. The detection rates and types of pesticide residues in different varieties of red jujube were different. The detection rates of pesticide residues in winter jujube were 93.33% and 15 kinds of pesticides were detected, which were significantly higher than those in Hui jujube and Jun jujube. The risk of chronic dietary intake and acute dietary intake of pesticides detected in jujube were far less than 100%, which was in an acceptable range. The high and medium risk pesticides in winter jujube were methamamectin benzoate, mite, biphenthrin, thiophosphate, acetamidine and permethrin. The medium risk pesticides in Hui jujube and Jun jujube were: phosphorus, propylene bromphosphorus and acetamidine. There were high risk and medium risk samples in the winter jujube samples, but the Hui jujube and Jun jujube samples were both medium risk and low risk samples. The quality and safety of jujube in Xinjiang is generally good, but the risk of pesticide residue in winter jujube is generally high, which should be paid attention to.

This study aimed to establish an evaluation method for quality uniqueness and batch stability of Maotai-flavor Baijiu of specific brand. In this study, Gas chromatography-mass spectrometry (GC-MS) and similarity evaluation system for chromatographic fingerprints of TCM were used to establish a fingerprint of Maotai-flavor Baijiu of specific brand. As well as, comprehensive evaluation quality uniqueness and batch stability of Maotai-flavor Baijiu of specific brand was conducted based on similarity evaluation and chemical pattern recognition (hierarchical clustering and principal component analysis). The results showed that evaluation standard for quality uniqueness and batch stability of Maotai-flavor Baijiu of specific brand was fingerprint similarity greater than 0.99, which could effectively distinguish Maotai-flavor Baijiu of specific brand from other brands. The results of chemical pattern recognition showed that Maotai-flavor Baijiu of specific brand and other brands of Maotai-flavor Baijiu were obviously classified. Thus, the quality uniqueness and batch stability of Maotai-flavor Baijiu of specific brands could be effectively evaluated by the fingerprint similarity and chemical pattern recognition. 17 substances were found by principal component analysis, which caused the difference between Maotai-flavor Baijiu of specific brand and other brands. Hexanoic acid, hexanoic acid, ethyl ester, 1-hexanol, acetic acid, benzeneacetic acid, ethyl ester, propanoic acid, 2-hydroxy-, ethyl ester, hexadecanoic acid, ethyl ester, butanoic acid, 1-butanol, 3-methyl-, 1-propanol, 2-methyl-, n-propyl acetate, 1-propanol, 2-butanol , propanoic acid, 2-methyl-, ethyl ester, butanoic acid, 3-methyl-, ethyl ester, propanoic acid, ethyl ester, 1-butanol were included. These substances were the inherent embodiment of Maotai-flavor Baijiu of specific brand uniqueness. This study provides theoretical basis and technical support for the quality control of Maotai-flavor Baijiu of specific brand.

The method for the determination of migration of lactide in polylactic acid (PLA) food contact material by gas chromatography-mass spectrometry (GC-MS) was established. Olive oil simulants were extracted by acetonitrile, centrifuged and filtered, and then analyzed by GC-MS. Isooctane simulants were directly filtered and analyzed by GC-MS. The method could achieve the determination of lactide migration in PLA. The limit of detection was 0.01 mg/kg and the recoveries at spiked levels were 80.0%~120.0%. The relative standard deviations were 2.6%~6.6% (n=6). Seven PLA samples were analyzed by the method. The detection rate was 85.7% and the range of concentration were 0.033~1.1 mg/kg. The method had the advantages of high sensitivity, high recovery and accuracy. The detection limit can meet the requirements of regulations. The method was suitable for migration of lactide in PLA food contact materials. The results showed that the detection rate of migration of lactide in PLA samples was high and migration of lactide should be paid attention to. Compared with isooctane, the migration of olive oil in the sample was higher than that of isooctane under the substitution condition due to the higher migration temperature of olive oil.

Objective: To establish a method to detect four genes: qnrS, aac(6')-Ib-cr, oqxA, oqxB, among the plasmid-mediated quinolone resistance (PMQR) genes carried by foodborne Salmonella by applying a novel liquid-phase chip technique. Methods: For the four PMQR genes carried by foodborne Salmonella: qnrS, aac(6')-Ib-cr, oqxA, and oqxB, corresponding primers and microspheres were designed, and liquid-phase microarray technology was used to perform specificity experiments on seven standard strains. Reproducibility and sensitivity experiments were performed on four foodborne Salmonella strains containing one PMQR gene each. 71 quinolone resistant Salmonella strains from foodborne risk monitoring were tested, and a comparison experiment with ordinary PCR was carried out. Results: A method for the detection of four PMQR genes, qnrS, aac(6')-Ib-cr, oqxA and oqxB, in foodborne Salmonella was successfully established by liquid-phase microarray technology. The LOD (limit of detection) of qnrS, aac(6')-Ib-cr, oqxA and oqxB were 5, 25, 10 and 10 CFU/mL respectively. The median fluorescence values (MFI) of all positive determinations were ≥5 times those of the negative control group. The coefficients of variation (CV) of the repeatability experiments were less than 5%. In the specificity experiments, all quinolone resistant Salmonella strains were detected, and no cross-reactivity with other non-target bacteria was observed. The detection rate of qnrS, aac(6')-Ib-cr, oqxA and oqxB were 29.6% (21/71), 35.2% (25/71), 28.2% (20/71), 23.9% (17/71) respectively. The coincidence rate between the liquid chip technology and PCR was 100%. Conclusion: The experimentally established liquid-phase chip technique for the detection of foodborne Salmonella plasmid-mediated quinolone resistance genes qnrS, aac(6')-Ib-cr, oqxA and oqxB is characterized by high sensitivity, good specificity, stability, and accurate results, which can provide technical support for the detection of foodborne Salmonella PMQR genes and the monitoring of drug resistance.

The main chemical components of saponins extracted from quinoa and the components in the blood of rat after oral administration were analyzed and identified by ultra-performance liquid chromatography coupled with Q-Exactive mass spectrometry (UPLC-Q-Exactive-MS/MS). Hypersil Gold VANQUISH C₁₈ column (2.1 mm×100 mm, 1.8 μm) was used. The mobile phase was formic acid water-formic acid acetonitrile gradient elution, the column temperature was 30 ℃, the analysis time was 35 min, the flow rate was 0.3 mL·min⁻¹. Electrospray ion source (ESI), positive and negative ion sources and Full ms/dd-ms² mode were used for detection. The results showed that the recovery rate, matrix effect, precision and stability of the method met the requirements of biological samples. A total of 15 saponins were identified in the saponin extract of quinoa, which were divided into three oleanolic acid saponin types, five hederagenin saponin types, six phytolaccagenic acid saponin types and one serjanic acid saponin type according to the configuration of aglycones. Male Sprague Dawley (SD) rats were selected as the experimental object, after intragastric administration of quinoa saponin extract at 175.5 mg·kg⁻¹, at 0, 0.5, 1, 2 and 4 hours after administration, blood was taken from the orbit, the plasma of rats took buspirone hydrochloride as the internal standard, precipitated protein with methanol, centrifuged, filtered by microporous membrane, and then injected for analysis. The results showed that six prototype saponins and trace hydrolyzed hederagenin and serjanic acid glycosides were detected in the blood components of rat plasma. Through the analysis of the components of the extract and the components entering the blood, 15 saponins in quinoa saponins were identified and their cleavage laws were found, and the changes in the relative contents of the components into the blood of rat plasma were found. The chemical composition and metabolic characteristics of triterpenoid saponins in quinoa were preliminaries elucidated, which provided a theoretical basis for further research and application of quinoa.

In this paper, the spectral characteristics of extra virgin olive oil mixed with different proportions of olive oil (refined olive oil), rapeseed oil, corn oil and soybean oil were investigated. The adulterated samples and pure oil samples were rapidly detected by fluorescence spectroscopy and ultraviolet spectroscopy. The results showed that the spectral characteristics of extra virgin olive oil were quite different from other vegetable oils, and there was a good linear relationship between the adulteration volume and absorbance of adulterated extra virgin olive oil (R²>0.89), which realized the qualitative identification and quantitative detection of extra virgin olive oil. The quality control system of extra virgin olive oil and its adulteration detection and analysis technology was established. The minimum detection limit was 1% and the linear range was 5%~100% (v/v). Systematic cluster analysis accurately classified all extra virgin olive oils into one subclass, which also confirmed the stability and reliability of this method. This simple and fast detection technology is conducive to the research and development of real-time, online olive oil detection and analysis technology for extra virgin olive oil portable detection equipment, and provides a favorable technical guarantee for Chinese olive oil quality identification and industrial development.

A method was developed for the simultaneous determination of fat-soluble vitamins A, D₂, D₃ and α-, β-, γ-, δ-vitamin E in children's formula milk powder by combining online solid phase extraction (SPE) and two-dimensional liquid chromatography. The saponified samples were directly injected into the constructed system and purified by using the polymeric-based PLRP-S column as the SPE column. Then the target analytes were eluted in back-flush mode from the SPE column by SPE pump and refocused on the head of the first-dimensional column by using online dilution. Vitamins A and four E homologues were separated on a NuovaSil^TM PFP column (4.6 mm×150 mm, 3 μm) as the first-dimensional column using a mobile phase consisting of methanol and 0.1% formic acid in water by gradient elution, and vitamins D₂ and D₃ were separated on a ChromCore PAH column (4.6 mm×150 mm, 3 μm) as the second-dimensional column using a mobile phase consisting of methanol and acetonitrile (90:10, v/v). The results showed good linearity in the range of 5.0~500.0 ng/mL for vitamin A, 1.0~100.0 ng/mL for vitamin D and 50.0~5000.0 ng/mL for vitamin E, and the correlation coefficients were all better than 0.9999. The limits of quantification for vitamins A, D₂, D₃ and α-, β-, γ-, δ-vitamins E were 5.11, 1.22, 1.25, 83.82, 57.27, 56.61, 54.82 µg/100 g, respectively. The spiked recoveries were 91.20%~104.47%, and the relative standard deviations were 0.94%~3.34%. The results show that the method established in this paper has the advantages of simple pretreatment, high automation, high analytical efficiency, high accuracy and good reproducibility, and is suitable for the determination of vitamins A, D and E in children's formula milk powder.

In order to study the key aroma compounds of Zijuan white tea with different processing technologies, headspace solid-phase micro extraction and gas chromatography mass spectrometry (HS-SPME-GC-MS), combined with sensory evaluation, PCA validation, OPLS-DA analysis and relative odor activity value (rOAV), was used to analyze and screen the key aroma compounds of Zijuan white tea. The results showed that 82 major aroma components were detected, mainly alcohols, esters, heterocyclic and aromatic compounds, with relatively high contents of linalool, methyl salicylate, benzyl alcohol and β-Ionone. The results of rOAV analysis showed that 9 volatile organic compounds including 1-octen-3-ol, α-Ionone, phenylacetaldehyde and methyl salicylate contributed to the aroma formation of natural withering Zijuan white tea (TZW) with floral and fruity aroma and spicy medicinal aroma, and 9 volatile organic compounds including 1-octen-3-ol, α-Ionone, β-Ionone and benzaldehyde contributed to the aroma formation of compound withering Zijuan white tea (CZW) with floral and fruity aroma and spicy aroma. OPLS-DA analysis combined with rOAV showed that 1-octene-3-ol and methyl salicylate were the key compounds for aroma difference between TZW and CZW. In summary, the flower and fruit aroma of Zijuan white tea processed by natural wilting was more abundant, which could effectively improve the aroma quality of Zijuan white tea.

The contents of cadmium and arsenic in dried Auricularia auricula were rapidly detected by high definition X-ray fluorescence (HDXRF) spectrometry. In the process of the experiment, the dried Auricularia auricula samples were pre-treated, and the three experimental conditions of particle size, sample weight, and instrument measurement time were optimized. Figures of merit such as precision, reproducibility, and stability were evaluated. The results showed that, the optimal detection conditions of HDXRF were: particle size of 100 meshes, sample weight of 0.80 g, and measurement time of 600 s. This method allowed direct detection of cadmium and arsenic in 15 min, and a detection limit of 0.035 mg/kg of cadmium and 0.012 mg/kg of arsenic, respectively. The relative standard deviations (RSD) of precision, reproducibility and stability of HDXRF were all below 10%. Finally, the results of HDXRF were compared with inductively coupled plasma mass spectrometry (ICP-MS). The results were accurate and the relative errors were less than 20%. It indicates that the method of HDXRF can meet the rapid detection requirements of cadmium and arsenic in dried Auricularia auricula.

To develop a fast and convenient method for the molecular identification of donkey meat products, this study selected donkey meat and duck meat (a common meat used for adulteration) as the research objects, screened specific primers and TaqMan probes, and conducted sensitivity and specificity experiments with a portable Mini8 Plus real-time fluorescence quantitative PCR instrument. By drawing the amplification standard curve and determining the mass/DNA ratio constants of donkey meat and duck meat, it detected the real donkey meat samples and the simulated samples adulterated with different proportions of duck meat (20%, 40%, 60%, and 80%, respectively). The results showed that the method had good specificity for both donkey meat and duck meat, which could be clearly distinguished from meat from horses, pigs, goats, sika deer, cattle, chickens, and dogs. The detection limit of donkey-derived DNA components was 0.01 ng/μL, and that of duck-derived DNA components was 0.1 ng/μL. Its sensitivity to duck meat components in the mixture of donkey meat and duck meat was 0.1% (w/w). The established standard curve showed a sound linear relationship. The amplification standard curve of donkey DNA was: y=−3.584x+27.003, R²=0.9982. The amplification standard curve of duck DNA was: y=−3.538x+30.907, R²=0.9991. A market pilot survey was conducted on 35 donkey meat samples using the established method, and revealed that 6 donkey meat samples (17.1%) contained duck meat. These results indicated that the real-time PCR method could be used for the rapid and accurate detection of other meat (such as duck meat) adulterated in donkey meat products. The combination of a simple detection procedure with a portable real-time PCR system provides technical support for food adulteration monitoring and control at the retail or market level.

In order to elucidate the influences of pre-harvest spraying diethyl aminoethyl hexanoate (DA-6) on the disease occurrence in longan fruit during postharvest storage and its possible mechanism, fruit of ‘Fuyan’ longan at 70, 90 and 110 days after full bloom was sprayed with DA-6 solution at the concentration of 10 mg/kg, and the fruit sprayed with distilled water served as control. The harvested longan fruit were stored at (28±1) ºC. During storage, the index of longan fruit disease, the contents of lignin and total phenolics, the activities of phenylalnine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), chitinase (CHI) and β-1,3-glucanase (GLU) in longan pericarp were evaluated. When stored for 6 d, the fruit disease index in 10 mg/kg DA-6-treated longan was 11.59% lower than control longans. The results also indicated that, contrasted to the control samples, during postharvest storage, pre-harvest spraying DA-6 could lower index of fruit disease, reduce activities of PPO and POD, but retain higher activities of PAL, CHI and GLU, as well as maintain higher levels of lignin and total phenolics. These findings suggested that pre-harvest spraying DA-6 could effectively suppress disease development of postharvest longan fruit, which was due to DA-6 induced-the enhanced activities of disease resistance related-enzymes and the reduced activities of phenols oxidation related-enzymes, the increased levels of disease-resistant substances, and then the enhanced disease resistance.

The objective of this work was to investigated the influence of chlorogenic acid (CA, 0.3 mmol/L) and CA (0.3 mmol/L) complex salicylic acid (SA, 0.1 mmol/L) on green asparagus postharvest quality during cold storage (4±2 ℃). The rot rate, respiration rate, chlorophyll content, cellulose content, V_C content, total phenol content, superoxide anion radical content, the key enzymes of the enzymatic system catalase (CAT), polyphenol oxidase (PPO), peroxidase (POD) and total superoxide dismutase(T-SOD) enzyme activities were measured as indicators. The results showed that CA and CA+SA treatments reduced respiratory peaks of asparagus significantly, which was 7.21% and 6.22% lower than that of CK respectively (P<0.05). The two treatments could maintain higher level of chlorophyll and V_C content, increased total phenol content and the activities of CAT, POD and T-SOD, inhibited the decay rate, superoxide anion and PPO activities, the CAT activity peaks were appeared in advance by 4 days. CA+SA treatment was better than CA treatment. CA+SA reduced the cellulose content after 8 d storage significantly (P<0.05), the CAT activitie peak was 1.92 times comparing with CK, but CA had no effect on the CAT activity peaks and cellulose content. These results indicated that CA+SA could maintain the storage quality of green asparagus well, and provide some theoretical basis for the application of the postharvest storage and preservation technology of green asparagus.

Peach fruit is rich in nutrition, easy to digest and absorb, and loved by consumers. However, peach fruits are prone to mechanical damage after harvesting, decay and quality loss, limiting their commercial value. This study investigated the effect of different precooling rates on the reduction of mechanical damage in peaches after harvest. 'Hujingmilu' peach fruits were subjected to precooling treatments (rapid precooling for 3 h and slow precooling for 16 h, reducing the core temperature of the fruit from 27 ˚C to 9 ˚C), with the control (Control check, CK) being without precooling. Afterwards, the fruits were subjected to compression damage (A texture analyzer with a probe diameter of 100 mm, a test depth of 10 mm and an extrusion speed of 1.5 mm/s was used to simulate the compression process). Overall, the precooling treatment, especially the rapid precooling treatment of 3 h, reduced bruise index, decay rate and weight loss rate, delayed the decline of fruit firmness during storage and accelerated the rise of phenylalanine ammonia lyase activity in the late storage period. In particular, the bruise index and decay rate of the fruits subjected to rapid precooling (3 h) were reduced by 11.7% and 8.3%, respectively, compared to the control treatment. Furthermore, the precooling treatments, regardless of time (3 h or 16 h), minimised increase in respiration rate, ethylene production, malondialdehyde content and polyphenol oxidase activity in the peach fruit with compression damage. The polyphenol oxidase activities in rapid precooled and the slow precooled fruits were 75.7% and 72.1%, respectively of the control at 21 d of storage. In addition, the precooling treatments also delayed the increase in total phenolic content, with rapid and slow precooling having 85.1% and 92.1%, respectively of phenolic content contained in the control treatment at 7 d of storage. In conclusion, rapid precooling of postharvest peach fruit prior to compression damage can reduce quality deterioration and decay of the peach fruit, and therefore, could improve the marketability of the fruit.

In order to investigate the effects of temperature on the quality of Procambarus clarkiii during waterless preservation, the changes in survival rates, muscle flesh quality, and physiological indicators of Procambarus clarkiii were analyzed under different waterless storage temperatures. The results showed that the survival rates of Procambarus clarkii in those of 4~16 ℃ groups were 80%~90% after 72 h of waterless preservation, the 24 ℃ group dropped to 40%, and the 32 °C group had reached zero. The moisture content, water-holding capacity, muscle hardness, and elasticity of muscle decreased significantly with the increase in temperature and time (P<0.05). The muscle pH was decreased by the production of lactic acid. The activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) content in 4, 24 and 32 ℃ groups were increased significantly with the extension of storage time (P<0.05), the oxidative stress response value of 8~16 ℃ groups was lower than those of 4, 24 and 32 ℃ groups. The activities of acid phosphatase (ACP), alkaline phosphatase (AKP), and lysozyme (LZM) were increased significantly in 4, 24, and 32 ℃ groups (P<0.05), and the changes were relatively stable in those of 8~16 ℃ groups. The results indicated that the survival rates and muscle quality of Procambarus clarkii might be improved by keeping the appropriate low temperature in the range of 12~16 ℃ during waterless preservation, which was related to the maintenance of low oxidative stress levels and good immune mechanisms. The results would provide a theoretical basis for the waterless storage and transportation of Procambarus clarkiii.

In this paper, the active peptides were obtained from Acetes chinensis with protease, and then the immunoregulatory function and mechanism of them on the immunosuppressed mice were explored by establishing an immunosuppressive mouse model. Mice were randomly divided into six groups: Normal control group, model group, positive control group and low, medium and high dose groups, among which, the dose groups were given 0.25 g· kg⁻¹ BW, 0.5 g·kg⁻¹ BW, 1.0 g·kg⁻¹ BW A. chinensis active peptide. The results showed that the body weight of the immunosuppressed mice in dosegroups was significantly increased (P<0.05), and the thymus index of the immune organ indexes were remarkably improved (P<0.05) after being stimulated by the active peptides of Acetes chinensis. The serum levels of immunoglobulins (IgA, IgG, and IgM) and cytokines (IL-2, IL-6, and TNF-α) in mice were enhanced (P<0.05), and the total number of peripheral blood leukocytes was increased. In addition, NK cells activity was also significantly enhanced (P<0.05). To sum up, the active peptides of A. chinensis could improve the immune function damage caused by immunosuppression, and the immunoregulatory function of immunosuppressed mice.

This study aimed to investigate the effect of commercial protease enzymolysis and in vitro simulated gastrointestinal digestion on the release of ACE inhibitory peptides from the defatted goat milk powder with high digestibility, and to evaluate the necessity and the extent of enzymatic hydrolysis. Neutrase, alcalase, protamex, and flavourzyme were used for the enzymolysis of the defatted Kuishan goat milk powder. The goat milk and its enzymatic hydrolysates were further digested via simulated gastrointestinal digestion in vitro. The peptide content, ACE inhibitory activity and molecular weight distribution of the enzymatic hydrolysates and the simulated gastrointestinal digests were determined. Results showed that after the simulated gastrointestinal digestion in vitro, the peptide content and ACE inhibitory activity of the goat milk powder digests were 20.81 mg/mL and 62.55%, respectively. However, after moderate enzymatic hydrolysis by alcalase and flavourzyme, the peptide content and ACE inhibitory activity of simulated gastrointestinal digests decreased. After moderate enzymolysis by protamex, the peptide content and ACE inhibitory activity of simulated gastrointestinal digests were increased slightly to 22.67 mg/mL and 69.29%, respectively. After moderate enzymolysis by neutrase, the peptide content and ACE inhibitory activity of simulated gastrointestinal digests were significantly increased to 23.76 mg/mL and 81.10%, respectively. The molecular weight (MW) distribution results showed that after in vitro simulated gastrointestinal digestion, the amount of the small molecular peptides with MW<1000 Da increased from 70.77% to 90%. Above results indicate that Kuishan goat milk powder can exert ACE inhibitory activity after gastrointestinal digestion, and the ACE inhibitory activity can be further increased by 28.83% after neutral protease hydrolysis to degree of hydrolysis of 8%. Therefore, it was necessary to further enzymatic hydrolysis to a certain extent.

With the global development of China's brewing engineering industry, the demand for cultivating professional and compound talents with international competitiveness is increasing. Teaching English for brewing engineering can support the development of international compound talents with excellent comprehensive professional quality and systematic knowledge structure. However, professional English teaching still faces the dilemma of a lack of systematic environmental training, and knowledge points are plenty and complicated. Especially the Jiang-flavor Baijiu with unique Chinese characteristics involves a traditional complex brewing process. The conventional teaching model is challenging to meet the needs of comprehensive and systematic rofessional English training and application. While the virtual simulation technology of brewing engineering can provide a virtual system training platform for professional English teaching. Therefore, three virtual simulation experimental projects of sauce-flavored baijiu brewing technology, small beer production and fermentation technology, and wine production technology have been introduced during professional English teaching. Students conduct systematic training from the perspective of professional English in a virtual simulation environment and strengthen the comprehensive use of professional English in the offline production practice session. This teaching method helped students to effectively consolidate and apply the specialized English knowledge of brewing engineering for comprehensive large-scale training, which can be used for continuous exploration by similar majors or colleges and further promotion and improvement.

Gastrodia elata is a plant with both food and medicine. In the field of traditional Chinese medicine, it is often used to treat dizziness, headache, hemiplegia, etc. Modern medical research has found that Gastrodia elata has good effects in improving cardiovascular and cerebrovascular health, anti epilepsy, and improving hypertension. Gastrodia elata is often used in functional food to improve sleep. With the deepening of modern pharmacological research, the main active ingredients and action mechanism of gastrodia elata have been revealed and further improved, which has expanded the application range, development prospect and value of functional claims of Gastrodia elata in the field of health food. This paper expounded the basis for the compliance use of Gastrodia elata raw materials as functional food raw materials in China, summarized and analyzed the application status of Gastrodia elata and its extracts as functional food raw materials, and summarized the safety evaluation and related health functions of Gastrodia elata. In order to provide reference for the compliant use, research and development and clinical application of Gastrodia elata raw materials in functional food in China.

Soybean protein isolate processing and production produces a large amount of soybean whey wastewater, which causes environmental pollution and waste of resources directly discharged. Soybean whey wastewater contains soybean whey proteins (SWP), soybean isoflavones, soybean oligosaccharides and other nutrients, of which soybean whey proteins application value is extremely high, rich in trypsin inhibitors, β-amylase, soybean hemagglutinin, lipoxygenase and other functional factors. Therefore, with regard to the recycling of soy whey proteins, this paper sumerizes the main components in soybean whey proteins, analyses functional properties and research purposes of each component, and sortes out the recovery methods and applications of soy whey proteins. The aim of this paper is to provide a theoretical and technical reference for high value utilisation in industrial production practice.

Bacterial exopolysaccharide (EPS) is a secondary metabolite that is synthesized and secreted outside the cell wall during bacterial growth and metabolism. It can regulate the initial attachment of cells to different substrates and protect cells against environmental stress and dehydration. As a potential prebiotic, EPS has the characteristics of safety, non-toxicity and unique physical and chemical properties, and is widely used in the fields of food, medicine, biology and industry. However, the bacterial metabolic system is complex, and the biosynthetic mechanism of EPS has not been fully elucidated. Cyclic diguanylate (c-di-GMP) is an important second messenger, and it plays an important role in the regulation of many physiological activities such as biofilm formation, motility, adhesion, virulence and EPS synthesis. The analysis of the transcriptional regulation mechanism of c-di-GMP provides a new idea for exploring the biosynthesis mechanism of bacterial EPS. This paper summarizes the characteristics and synthetic degradation pathways of c-di-GMP in detail, and focuses on the regulatory mechanism of c-di-GMP in the process of bacterial EPS biosynthesis. This paper provides a theoretical basis for revealing the mechanism of bacterial EPS biosynthesis and the structure-activity relationship.

Cellulose is one of the abundant natural polymers in nature, which is renewable, environmentally friendly and biocompatible. Nanocellulose is prepared by physical or chemical method from cellulose. The morphology and physicochemical properties of nanocellulose are significantly affected by the different methods of preparation. Nanocellulose has attracted much attention in food industry due to its high surface area and modulus, amphiphilicity, biocompatibility and safety. In this paper, the application of nanocellulose prepared by agricultural and forestry by-products in food packaging, emulsifying stabilizer, enzyme immobilization and rapid nondestructive detection of food contaminants based on surface-enhanced Raman spectroscopy (SERS) are summarized. Challenges in the application of nanocellulose in food industry are analyzed, and the research development tendency is prospected.

Natural polysaccharides have numerous biological activities, a stable structure, a large molecular weight, and a high level of safety, making them a popular choice for use as emulsifiers in the food business. However, polysaccharides' strong hydrophilicity and insolubility caused them to perform poorly during emulsification in high-temperature and high-salt environments, restricting their widespread use. To improve their ability to form emulsions, polysaccharides can have their molecular weight, structure, hydrophobicity, and other functional qualities altered. This paper reviews the effects of physical, chemical, and biological modification methods on the molecular structure and emulsification properties of polysaccharides, as well as the status and progress of research on the use of modified polysaccharides in emulsions, and also analyzes the issues with the current modification methods and forecasts the future development trend, with the goal of providing a theoretical foundation for further research on improving the emulsification property and broadening their application fields.

Hydrogel is a polymer material composed of a hydrophilic three-dimensional network structure, which can quickly absorb water, swell, and maintain the swollen state to avoid significant water loss. It can provide sufficient capacity to accommodate a variety of materials, including small molecules, polymers and particles, among which, those that exhibit antibacterial properties are called antibacterial hydrogels. Antibacterial hydrogels have been widely used in many fields, such as biomedicine, textile, chemical industry, agriculture, and tissue engineering. They have great application potential in food packaging, food quality indication, and food preservation, but have not attracted enough attention. According to the type of active ingredients, antibacterial hydrogels can be divided into three categories: Natural polymer antibacterial hydrogel, hydrogels loaded with inorganic/organic antibacterial substances, and antibacterial hydrogels containing light-activated or light-responsive materials. This review expounds on the antibacterial mechanism and application status of these three types of antibacterial hydrogels, in order to provide a broader idea for the application of hydrogels in the field of food to exert its antibacterial effect.

As a non-thermal processing technology, high hydrostatic pressure (HHP) technology is often used to change the structure and physicochemical properties of proteins. Combining HHP with heat treatment can not only reduce the pressure and time required for HHP treatment, but also greatly improve the quality of meat products. In this paper, the effects of temperature-pressure combined treatment technology (TP) on the structure and gel properties of myofibrillar proteins (MP) together with the relevant mechanism are systematically reviewed, providing theoretical support for the application and promotion of this technology.

Quinolone antibiotic residues present a high risk for food safety and have gained widespread attention. Nanomaterials based sensors have the advantages of on-site application, sensitivity, and small sample volume requirement and has attracted significant interest in on-site detection technology research for quinolone antibiotics. This paper introduces the application of optical sensors including fluorescence, colorimetry, SERS, ICA and electrochemical sensors based on diverse nanomaterials in quinolone antibiotics detection and summarizes the characteristics of diverse sensors. The application of nanomaterials including quantum dots and upconversion in optical sensors, as well as those of carbon and metal nanomaterials and redox media in electrochemical sensors are reviewed and evaluated. The objective of this work is to provide new concepts for antibiotics detection in food and the development of sensors.

Parkinson's disease (PD) is a common neurological disorder of the brain. In recent years, there is increasing evidence that intestinal flora dysbiosis is closely related to the occurrence and development of PD. This suggests that intestinal microorganisms may be a new strategy for the treatment of PD. Probiotics are a group of active microorganisms that can colonize the host gut and play a beneficial role in the health of the body, and are of great significance to maintaining the intestinal microecological balance. Studies have shown that probiotics can effectively prevent and improve PD through the gut-brain axis, and the potential mechanisms of action include regulating intestinal microecology, alleviating inflammatory response and oxidative stress damage, and promoting the expression of neurotrophic factors. This article reviews the changes of intestinal flora in PD, the mechanisms of intestinal flora in the pathogenesis of PD, and the improvement effect and mechanisms of probiotics on PD-related symptoms, in order to provide a theoretical basis for probiotics to prevent and alleviate PD.