Effect of Enzymolysis and in Vitro Simulated Gastrointestinal Digestion on the ACE Inhibitory Activity of Defatted Goat Milk Powder
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摘要: 本研究旨在探究商业蛋白酶酶解与体外模拟胃肠消化对高消化率的脱脂羊奶粉释放ACE抑制肽的影响,以评价脱脂羊奶粉酶解必要性及所需酶解程度。采用中性蛋白酶、碱性蛋白酶、复合蛋白酶和风味蛋白酶对脱脂后的圭山羊奶粉进行酶解反应,并对脱脂羊奶粉及其酶解物进行体外模拟胃肠消化,测定酶解液及模拟胃肠消化液的多肽含量、ACE抑制活性以及分子量分布。研究发现,羊奶粉经过体外模拟胃肠消化后,消化液的多肽含量与ACE抑制率分别达到20.81 mg/mL和62.55%;而经过碱性蛋白酶和风味蛋白酶的适度酶解,其模拟胃肠消化液多肽含量与ACE抑制活性反而下降;经过复合蛋白酶的适度酶解,其模拟胃肠消化液的多肽含量与ACE抑制活性小幅度提高,分别达到22.67 mg/mL和69.29%;经过中性蛋白酶的适度酶解,其模拟胃肠消化液多肽含量与ACE抑制活性均显著提高,分别达到23.76 mg/mL和81.10%。分子量分布结果显示,经过体外模拟胃肠消化后,<1000 Da的小分子肽由酶解液中的70.77%提高到90%。综上,圭山羊奶粉经过体内胃肠消化就可以释放出较多的ACE抑制肽,而经过中性蛋白酶酶解至水解度8%后,ACE抑制活性还可以再提升28.83%,因此在一定程度上具有进一步酶解的必要性。Abstract: 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.
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表 1 羊奶蛋白氨基酸评分
Table 1. Amino acid rating of goat milk protein
必需氨基酸 婴幼儿均值 2~5岁儿童 10~12岁儿童 成人 His 1.11 1.52 1.52 1.80 Ile 1.42 2.32 2.32 5.01 Leu 1.30 1.83 2.75 6.37 Lys 1.23 1.40 1.85 5.08 Met+Cys 0.73 1.23 1.40 1.81 Phe+Tyr 1.20 1.37 3.93 4.56 Thr 1.46 1.85 2.25 7.00 Val 1.23 1.94 2.71 5.21 Trp / / / / 表 2 蛋白酶的酶活、最适作用条件及酶切位点
Table 2. Enzymatic activity, optimum reaction conditions and cleavage sites of the different proteases
蛋白酶 蛋白酶活力(U/g) 最适作用条件 主要酶切位点 中性蛋白酶 155153.80 pH7.0; T 50 °C 酶切位点较为广泛 碱性蛋白酶 220157.69 pH9.0; T 50 °C 疏水性氨基酸残基,
如Ala和Leu复合蛋白酶 184000.00 pH6.5; T 50 °C 酶切位点较为广泛 风味蛋白酶 26553.85 pH6.5; T 50 °C 酶切位点较为广泛 注:T 温度。 表 3 羊奶粉基本成分
Table 3. Elementary components of goat milk powder
指标 水分 灰分 粗蛋白 脂肪 总糖 含量(%) 2.26±0.26 4.60±0.19 20.00±0.21 19.40±0.36 52.00±0.34 表 4 羊奶蛋白的氨基酸组成及含量
Table 4. Amino acid composition and content of goat milk protein
氨基酸 含量(%) 氨基酸 含量(%) Asp 7.96±0.11 Ile 6.51±0.10 Thr 6.30±0.09 Leu 12.11±0.06 Ser 4.88±0.01 Tyr 4.29±0.01 Glu 21.01±0.25 Phe 4.36±0.02 Gly 2.11±0.01 His 2.89±0.01 Ala 3.70±0.02 Lys 8.13±0.09 Val 6.77±0.06 Arg 3.96±0.03 Met 3.08±0.02 Pro 1.93±0.01 表 5 羊奶蛋白必需氨基酸及氨基酸分布
Table 5. Amino acid distribution and essential amino acids of goat milk protein
氨基酸种类 含量(%) 必需氨基酸 Lys、Trp、Phe、Met、Thr、Ile、Leu、Val 47.27 疏水性氨基酸 Ala、Phe、Ile、Leu、Met、Pro、Val、Trp 38.45 亲水性氨基酸 Ser、Thr、Tyr、Cys、Gly 17.58 酸性氨基酸 Glu、Asp 28.98 碱性氨基酸 Lys、Arg、His 14.98 表 6 羊奶蛋白营养价值分析
Table 6. Nutritional value of goat milk protein
营养评价参数 评分 E/T(%) 47.27 PER I 4.75 PER II 4.58 BV 93.63 表 7 中性蛋白酶酶解物及其胃肠模拟消化产物中肽的相对分子质量分布和其分布范围
Table 7. Molecular weight distribution of the neutrase hydrolysates and its simulated gastrointestinal digests
分子量范围
(Da)酶解液各组分含量
(%)胃肠模拟消化液各组分含量
(%)>10000 2.83 0.34 5000~10000 2.52 0.27 3000~5000 3.31 0.78 2000~3000 6.00 1.64 1000~2000 14.57 6.98 500~1000 19.45 16.96 180~500 36.37 46.43 <180 14.95 26.60 -
[1] ZENG Q, CAI Z X, LIU Y P, et al. A comprehensive review on bioactive peptides derived from egg proteins[J]. Food Science,2021,42(19):362−378. [2] LIU D, GUO Y, MA H. Production, bioactivities and bioavailability of bioactive peptides derived from walnut origin by-products: A review [J/OL]. Critical Reviews in Food Science and Nutrition, 2022.https://doi.org/10.1080/10408398.2022.2054933. [3] WANG R X, YI L, JI R M T. Research progress on the bioactive peptides in camel milk[J]. Journal of Chinese Institute of Food Science and Technology,2020,20(7):299−306. [4] LI H, LÜ Y, DING K, et al. Preparation and function assessment of antihypertensive peptides from food[J]. Food and Nutrition in China,2015,21(1):26−30. [5] LIU D, CHEN M, ZHU J, et al. A two-stage enzymolysis method and its application in exerting antioxidant activity of walnut protein[J]. Frontiers in Nutrition,2022,9:889434. doi: 10.3389/fnut.2022.889434 [6] HUANG S, LI Y, LI C, et al. Effects of ultrasound-assisted sodium bisulfite pretreatment on the preparation of cholesterol-lowering peptide precursors from soybean protein[J]. International Journal of Biological Macromolecules,2021,183:295−304. doi: 10.1016/j.ijbiomac.2021.04.125 [7] YANG X, LI Y L, LU F, et al. Effects of ultrasonic frequencies on ACE inhibitory activity of hydrolysate and gastrointestinal simulated digestive products from rice protein[J]. Journal of Chinese Institute of Food Science and Technology,2019,19(3):60−66. [8] LIU D, GUO Y, WU P, et al. The necessity of walnut proteolysis based on evaluation after in vitro simulated digestion: ACE inhibition and DPPH radical-scavenging activities[J]. Food Chemistry,2019,311:125960. [9] LIU D, GUO Y, ZHU J, et al. The necessity of enzymatically hydrolyzing walnut protein to exert antihypertensive activity based on in vitro simulated digestion and in vivo verification[J]. Food & Function,2021,12(8):3647−3656. [10] KASHYAP S, SHIVAKUMAR N, SEJIAN V, et al. Goat milk protein digestibility in relation to intestinal function[J]. The American Journal of Clinical Nutrition,2021,113(4):845−853. doi: 10.1093/ajcn/nqaa400 [11] SHU G, HUANG J, BAO C, et al. Effect of different proteases on the degree of hydrolysis and angiotensin I-converting enzyme-inhibitory activity in goat and cow milk[J]. Biomolecules,2019,8(4):101. [12] CHEN L, WANG J, SHU G, et al. Purification and production of novel angiotensin I-converting enzyme (ACE) inhibitory bioactive peptides derived from fermented goat milk[J]. Emirates Journal of Food and Agriculture,2018,30(9):742−749. [13] GU H F, ZHANG F X, ZHANG Y. In vitro digestion of proteins in goat milk formula[J]. Food Science,2013,34(19):302−305. [14] KETNAWA S, MARTINEZ A O, BENJAKUL S, et al. Gelatin hydrolysates from farmed giant catfish skin using alkaline proteases and its antioxidative function of simulated gastro-intestinal digestion[J]. Food Chemistry,2016,192(1):34−42. [15] LIU D D, ZHU J S, ZHANG X L, et al. Nutritional evaluation of walnut protein and its ameliorative effect on DSS induced acute colitis in mice[J]. Science and Technology of Food Industry,2022,43(20):372−379. [16] YANG X, LI Y, LI S, et al. Effects of ultrasound pretreatment with different frequencies and working modes on the enzymolysis and the structure characterization of rice protein[J]. Ultrasonics Sonochemistry,2017(38):19−28. [17] ADLERNISSEN J. Enzymic hydrolysis of food proteins[J]. Canadian Medical Association Journal,1986,172:1783−1785. [18] LI M, XIA S, ZHANG Y, et al. Optimization of ACE inhibitory peptides from black soybean by microwave-assisted enzymatic method and study on its stability[J]. LWT-Food Science and Technology,2018,98:358−365. doi: 10.1016/j.lwt.2018.08.045 [19] JIN J, MA H, ZHOU C, et al. Effect of degree of hydrolysis on the bioavailability of corn gluten meal hydrolysates[J]. Journal of the Science of Food and Agriculture,2015,95(12):2501−2509. doi: 10.1002/jsfa.6982 [20] BHASKAR B, ANATHANARAYAN L, JAMDAR S. Purification, identification, and characterization of novel angiotensin I-converting enzyme (ACE) inhibitory peptides from alcalase digested horse gram flour[J]. LWT- Food Science and Technology,2019(103):155−161. [21] MOHSIN A Z, SUKOR R, SELAMAT J, et al. Chemical and mineral composition of raw goat milk as affected by breed varieties available in Malaysia[J]. International Journal of Food Properties,2019,22(1):815−824. doi: 10.1080/10942912.2019.1610431 [22] ZHENG L, REN J, SU G, et al. Comparison of in vitro digestion characteristics and antioxidant activity of hot- and cold-pressed peanut meals[J]. Food Chemistry,2013,141(4):4246−4252. doi: 10.1016/j.foodchem.2013.06.081 [23] 邹平. 基于生物信息学与QSAR及分子对接的菜粕活性肽筛选及活性研究 [D]. 杭州: 浙江大学, 2014.ZOU Ping. Screening of bioactive peptides from rapeseed meal by bioinformatics, QSAR and molecular docking and research on their activity [D]. Hangzhou: Zhejiang University, 2014. [24] DASKAVA D C, YUCETEPE F, KARBANCIOGLU G H, et al. Angiotensin-I-converting enzyme (ACE)-inhibitory peptides from plants[J]. Nutrients,2017,9(4):316. doi: 10.3390/nu9040316 [25] SHAUKAT A, NADEEM M, RANJHA M, et al. Effect of ripening and in vitro digestion on free amino acids and angiotensin I converting enzyme inhibitory (ACE-I) potential of cow and Buffalo milk cheddar cheeses[J]. International Journal of Food Properties,2022,25(1):948−959. doi: 10.1080/10942912.2022.2070200 [26] WANG S, ZHAO M, FAN H, et al. Emerging proteins as precursors of bioactive peptides/hydrolysates with health benefits[J]. Current Opinion in Food Science,2022,48:100914. doi: 10.1016/j.cofs.2022.100914 [27] MA H, LIU B, LI S, et al. Enzymatic preparation of rice anti-oxidation peptide[J]. Transactions of the Chinese Society for Agricultural Machinery,2010,41(11):119−123. [28] ZAHARUDDIN N, BARKIA I, IBADULLAH W, et al. Identification, molecular docking, and kinetic studies of six novel angiotensin-I-converting enzyme (ACE) inhibitory peptides derived from Kenaf (Hibiscus cannabinus L.) seed[J]. International Journal of Biological Macromolecules,2022,220:1512−1522. doi: 10.1016/j.ijbiomac.2022.09.142 [29] RUI X, BOVE J I, SIMPSON B K, et al. Purification and characterization of angiotensin I-converting enzyme inhibitory peptides of small red bean (Phaseolus vulgaris) hydrolysates[J]. Journal of Functional Foods,2013,5(3):1116−1124. doi: 10.1016/j.jff.2013.03.008 [30] GONZALEZ M, VALLE M, ALUKO R E, et al. Production of antihypertensive and antidiabetic peptide fractions from quinoa (Chenopodium quinoa Willd.) by electrodialysis with ultrafiltration membranes[J]. Food Science and Human Wellness,2022,11(6):1650−1659. doi: 10.1016/j.fshw.2022.06.024