Food-derived protein hydrolysates and peptides:anxiolytic and antidepressant activities,characteristics,and mechanisms

Globally,the prevalence of anxiety and depression has reached epidemic proportions.Food-derived protein hydrolysates and peptides delivered through dietary supplementation can avoid the negative risks associated with traditional pharmaceuticals while delivering superior anxiolytic and antidepressant effects.This review summarizes current research on food-derived anxiolytic and antidepressant protein hydrolysates and peptides,and subsequently analyses their physicochemical characteristics and elaborates on their mechanisms.The aim of this work is to contribute to the in-depth study and provide a theoretical foundation for the development of related products to better serve patients with anxiety and depression.

Protein hydrolysates in animal nutrition：Industrial production, bioactive peptides,and functional significance

Recent years have witnessed growing interest in the role of peptides in animal nutrition. Chemical, enzymatic, or microbial hydrolysis of proteins in animal by-products or plant-source feedstuffs before feeding is an attractive means of generating high-quality small or large peptides that have both nutritional and physiological or regulatory functions in livestock, poultry and fish. These peptides may also be formed from ingested proteins in the gastrointestinal tract, but the types of resultant peptides can vary greatly with the physiological conditions of the animals and the composition of the diets. In the small intestine, large peptides are hydrolyzed to small peptides,which are absorbed into enterocytes faster than free amino acids（AAs） to provide a more balanced pattern of AAs in the blood circulation. Some peptides of plant or animal sources also have antimicrobial, antioxidant,antihypertensive, and immunomodulatory activities. Those peptides which confer biological functions beyond their nutritional value are called bioactive peptides. They are usually 2–20 AA residues in length but may consist of 〉20AA residues. Inclusion of some（e.g. 2–8%） animal-protein hydrolysates（e.g., porcine intestine, porcine mucosa,salmon viscera, or poultry tissue hydrolysates） or soybean protein hydrolysates in practical corn-and soybean mealbased diets can ensure desirable rates of growth performance and feed efficiency in weanling pigs, young calves,post-hatching poultry, and fish. Thus, protein hydrolysates hold promise in optimizing the nutrition of domestic and companion animals, as well as their health（particularly gut health） and well-being.

Peptidomic analysis of whey protein hydrolysates and prediction of their antioxidant peptides

Enzymatic hydrolysis of proteins is a breakdown process of peptide bond in proteins,releasing some peptides with potential biological functions.Previous studies on enzymatic hydrolysis of whey proteins have not identified the complete peptide profiles after hydrolysis.In this study,we reconstructed a profile of peptides from whey hydrolysates with two enzymes and different processing conditions.We also developed an ensemble machine learning predictor to classify peptides obtained from whey hydrolysis.A total of 2572 peptides were identified over three process conditions with two enzymes in duplicate.499 peptides were classified and chosen as potential antioxidant peptides from whey proteins.The peptides classified as antioxidants in the hydrolysates had a proportion of 13.1%-24.5%regarding all peptides identified.These results facilitate the selection of promising peptides involved in the antioxidant properties during the enzymatic hydrolysis of whey proteins,aiding the discovery of novel antioxidant peptides.

Suppression of postprandial blood glucose elevation by buckwheat(Fagpopyrum esculentum) albumin hydrolysate and identification of the peptide responsible to the function

The objective of this study is to evaluate the suppressive effect of buckwheat-albumin hydrolysate on postprandial hyperglycemia and identify the peptide responsible to the function. Buckwheat-albumin hydrolysate was prepared by using digestive enzymes and was orally administered to rats together with soluble starch. The blood was taken from the tail vein up to 90 min after oral administration to measure blood-glucose and plasma-insulin levels. The peptide with α-amylase inhibitory activity was purified from the buckwheathydrolysate by gel-filtration chromatography, α-amylase affinity chromatography, and high performance liquid chromatography(HPLC). The amino-acid sequence of the peptide was identified by a protein sequencer and was compared with that in the buckwheat-genome database. Buckwheat-albumin hydrolysate significantly suppressed the elevation of blood glucose level 15 min after starch administration. The amino-acid sequence of the peptide with α-amylase inhibitory activity was YVEPDCGNLGCCYHC in the parental protein of molecular mass 17.8 k Da and theoretical pI 4.77. The amino-acid sequence, molecular weight, and pI of the parental protein in buckwheat albumin were different from those of α-amylase inhibitor in wheat albumin. This study suggests that the novel α-amylase inhibitor identified in buckwheat albumin is a potential candidate for a functional food material to suppress postprandial blood glucose elevation.

Novel Antioxidant Peptides Derived from Enzymatic Hydrolysates of Macadamia Protein

In the present work, macadamia protein was enzymatic hydrolyzed to produce peptides which had abundant antioxidant activities. The relative antioxidant capacity was investigated through some in vitro models such as scavenging activity of DPPH radical, scavenging of ABTS+ radical and evaluation of the total antioxidant capacity assay. Macadamia protein was characterized by methods of DEAE cellulose cation-exchange chromatography and SDS-PAGE. Besides, method of price graph was used to compare the difference and to investigate the connection between the actual and ideal antioxidant value of the hydrolysates, aiming to reduce this difference.

Supplementation with yak (Bos grunniens) bone collagen hydrolysate altered the structure of gut microbiota and elevated short-chain fatty acid production in mice

In this study, yak bone collagen hydrolysate(YBCH)was produced by mixed proteases and provided to standard-diet mice at a different dose(low dose(LD), medium dose(MD), and high dose(HD))to investigate its effects on the composition of gut microbiota and short-chain fatty acids(SCFA)production. It was found that YBCH was mainly composed of small molecular peptides whose molecular weight below 2 000 Da. Notably, supplementation with different doses of YBCH could significantly downregulate the ratio of Firmicutes to Bacteroidetes in the fecal microbiota. At the family level, the Lachnospiraceae abundance was significantly reduced in the YBCH gavage groups(mean reduction ratio 41.7 %, 35.2%, and 36.4% for LD, MD, and HD group, respectively). The predicted functions of gut microbes in the MD group were significantly increased at “lipid metabolism” and “glycan biosynthesis and metabolism”. Moreover, the SCFA production in the YBCH groups was elevated. Especially, the concentration of acetic acid, propionic acid, and butyric acid in the MD group was separately increased 79.7%, 89.2%, and 78.8% than that in the NC group. These results indicated that YBCH might be applied in the development of functional food for intestinal microecological regulation.

Optimization of Hydrolysis Conditions for the Isolation of Angiotensin-I Converting Enzyme(ACE) Inhibitory Peptides from Rhopilema hispidum

To obtain the maximum angiotensin-I converting enzyme(ACE) inhibitory activity, the protein hydrolysis conditions of the jellyfish Rhopilema hispidum were optimized using response surface methodology(RSM). Trypsin was selected to produce R. hispidum protein hydrolysates(RPH) with ACE inhibitory activity. The optimal parameters for producing protein hydrolysates with the highest ACE inhibitory activity were as follows: hydrolysis time 5 h, hydrolysis temperature 50℃, and the enzyme-to-substrate ratio 6%. Under these conditions, the ACE inhibitory rate of RPH could reach 64.28% ± 5.72%. In addition, RPH contained high levels of Gly, Glu, Pro, Ala, Asp and Arg, with a molecular weight distribution range of 0.32–6.84 kDa. The following three novel ACE inhibitory peptides were isolated and identified: Ile-Gly-Glu-Thr-Gly-Pro, Gly-Ala-Thr-Gly-Pro-Ala-Gly-Tyr-Val and Gly-AlaPhe-Gly-Pro-Gly-Gly-Leu-Val-Gly-Arg-Pro. The IC_(50) values of the ACE inhibitory activity of these three purified peptides were 19.07, 27.42 and 31.26 μmol L^(-1), respectively. These results suggested that proteins and peptides isolated from R. hispidum could be utilized as antihypertensive functional food sources.

Separation and Identification of Glutamine Peptides from Defatted Soybean Meal by Enzymatic Hydrolysis

Glutamine peptides were obtained from defatted soybean meal by enzymatic hydrolysis using a combination of Protamex~? and trypsinase. The results showed that the extent of hydrolysis and the concentration of Gln peptides in the hydrolysate were 22.02%and 6.05 mmol/L, respectively. The hydrolysates were fractionated by size-exclusion chromatography on a Sephadex G-15 into five major fractions(GelF1–GelF5). The peptide(GelF1) fraction with the highest glutamine peptide content(51.8%) was further evaluated to determine its molecular weight distribution. Most(92.37%) peptides were less than 1 000 Da. Glutamic acid and glutamine were the most abundant amino acids, accounting for up to 12.98% of the total amino acid content. In addition, the total amino acid content in GelF1 was higher than that in GelF2 and GelF3.

Effects of brewers' spent grain protein hydrolysates on gas production, ruminal fermentation characteristics, microbial protein synthesis and microbial community in an artificial rumen fed a high grain diet

Background: Brewers' spent grain(BSG) typically contains 20% – 29% crude protein(CP) with high concentrations of glutamine, proline and hydrophobic and non-polar amino acid, making it an ideal material for producing valueadded products like bioactive peptides which have antioxidant properties. For this study, protein was extracted from BSG, hydrolyzed with 1% alcalase and flavourzyme, with the generated protein hydrolysates(AlcH and FlaH)showing antioxidant activities. This study evaluated the effects of AlcH and FlaH on gas production, ruminal fermentation characteristics, nutrient disappearance, microbial protein synthesis and microbial community using an artificial rumen system(RUSITEC) fed a high-grain diet.Results: As compared to the control of grain only, supplementation of FlaH decreased(P < 0.01) disappearances of dry matter(DM), organic matter(OM), CP and starch, without affecting fibre disappearances;while AlcH had no effect on nutrient disappearance. Neither AlcH nor FlaH affected gas production or VFA profiles, however they increased(P < 0.01) NH_3-N and decreased(P < 0.01) H_2 production. Supplementation of FlaH decreased(P < 0.01)the percentage of CH_4 in total gas and dissolved-CH_4(dCH_4) in dissolved gas. Addition of monensin reduced(P < 0.01) disappearance of nutrients, improved fermentation efficiency and reduced CH_4 and H_2 emissions.Total microbial nitrogen production was decreased(P < 0.05) but the proportion of feed particle associated(FPA) bacteria was increased with FlaH and monensin supplementation. Numbers of OTUs and Shannon diversity indices of FPA microbial community were unaffected by AlcH and FlaH;whereas both indices were reduced(P < 0.05) by monensin. Taxonomic analysis revealed no effect of AlcH and FlaH on the relative abundance(RA) of bacteria at phylum level, whereas monensin reduced(P < 0.05) the RA of Firmicutes and Bacteroidetes and enhanced Proteobacteria. Supplementation of FlaH enhanced(P < 0.05) the RA of genus Prevotella, reduced Selenomonas, Shuttleworthia, Bifidobacterium and Dialister as compared to control;monensin reduced(P < 0.05) RA of genus Prevotella but enhaced Succinivibrio.Conclusions: The supplementation of FlaH in high-grain diets may potentially protect CP and starch from ruminal degradation, without adversely affecting fibre degradation and VFA profiles. It also showed promising effects on reducing CH_4 production by suppressing H_2 production. Protein enzymatic hydrolysates from BSG using flavourzyme showed potential application to high value-added bio-products.

Antifatigue,Antioxidant and Immunoregulatory Effects of Peptides Hydrolyzed from Manchurian Walnut(Juglans mandshurica Maxim.) on Mice

The Manchurian walnut(Juglans mandshurica Maxim.) is rich in proteins, whereas this resource has not been used efficiently. The antifatigue, antioxidative and immunoregulatory effects of Manchurian walnut hydrolysate peptides(MWHPs)were evaluated in this study. MWHPs with a degree of hydrolysis of 32.23% were ultrafiltered and divided into three fractions,namely, high(> 10 k Da), medium(3–10 kDa), and low molecular weight(< 3 kDa), and then fed to mice continuously at doses of 200, 400 or 800 mg/(kg·d). The antifatigue, antioxidative, and immunoregulatory effects of the peptides were tested on the second and fourth weeks of MWHP administration. Results showed that low-molecular-weight MWHPs exerted significant antifatigue(prolonging swimming time, elevating liver glycogen contents, and reducing lactic acid contents), antioxidative(enhancing superoxide dismutase(SOD), GSH-Px, and catalase(CAT) activities and reducing malondialdehyde(MDA) content), and immunoregulatory(raising the immune-organ index and promoting T-lymphocyte proliferation and s Ig A secretion in the intestinal tract) effects. This research indicates that MWHPs have potential applications in health care and may be developed as a base for new functional foods.

Radical-scavenging activity,ACE-inhibiting capability and identification of rapeseed albumin hydrolysate

Albumin derived from rapeseed was hydrolyzed sequentially using alcalase and flavorzyme to produce antioxidant peptides.To identify antioxidant peptides,rapeseed albumin hydrolysate(RAH)was fractionated using size exclusion chromatography(G-25).The antioxidant activity and angiotensin I-converting enzyme(ACE)inhibiting activity of rapeseed peptides(RSP)purified from RAH were evaluated.The results revealed that RSP-4 had the highest ABTS radical-scavenging activity(TEAC value=0.24)and ACE-inhibiting capacity(IC50=0.19 mg/mL)compared to other fractions.Moreover,RSP-4 was identified as PFDSYFVC(977 D)by electrospray ionization(ESI)mass spectrometry and tandem mass spectrometry(MS/MS).©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Fractionation of edible bird’s nest glycoprotein hydrolysates:characterisation and antioxidative activities of the fractions

E dible bird’s nest(EBN)hydrolysates have been proven to exhibit enhanced bioactivities.However,being a macromolecule,fractions with different molecular weights would have different properties and bioactivities.Hence,this research was aimed to determine the chemical properties and antioxidant activities of freezedried(EBN_(FD))and spray-dried EBN(EBN_(SD))hydrolysates fractionated using gel permeation chromatography(GPC).Overall,two well-separated fractions were identified(EBN_(fFD1),EBN_(fFD2),EBN_(fSD1) and EBN_(fSD2)).EBNFD demonstrated significantly higher(P≤0.05)peptide(3.6%),total carbohydrate(27.7%)and sialic acid(18.2%)contents than that of EBNSD.Similar trend was observed in low molecular weight fractionates(EBN_(fFD2) and EBN_(fSD2)).Meanwhile,the first fractionates(EBN_(fFD1) and EBN_(fSD1))exhibited significantly higher(P≤0.05)hydroxyl radical(·OH)scavenging activity.Fourier transform infrared(FTIR)spectroscopy demonstrated that all EBN fractionates have similar spectrum,except in the region of N—H(amideⅡ)and C—H alkyl group.In conclusion,EBN fractionates with different molecular weights showed different chemical properties and antioxidant activities.

In vitro Antioxidant Effects of Porphyra haitanensis Peptides on H_2O_2-Induced Damage in HepG2 Cells

In this study,protein from Porphyra haitanensis was used as raw material to prepare an antioxidant peptide,and its antioxidant activity was evaluated in vitro.A model of H_2O_2-induced oxidative damage in Hep G2 cells was established,and the effects of Porphyra haitanensis hydrolysates (PHHs) on superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected.Finally,the structure of PHHs was identified by ESI-MS/MS.The results showed that the 1,1-diphenyl-2-pyridylhydrazine(DPPH)-free radical-scavenging ability of PHHs was the strongest (59.28%at 1.0 mg m L~(-1)) when hydrolyzed with an acidic protease for 4 h.PHHs with different concentrations had protective effects on H_2O_2-induced damage to Hep G2 cells,and the protective effect was enhanced with increasing concentrations.When the level was 400μg m L~(-1),the cell survival rate was as high as 88.62%.Moreover,PHHs can significantly reduce oxidative damage to Hep G2 cells by H_2O_2,improve SOD activity,and reduce MDA content.The tetrapeptide Asp-Lys-Ser-Thr,with a molecular weight of 448 Da,was identified as an important fraction of PHHs by high-resolution mass spectrometry.

大球盖菇酶解液中鲜味肽的分离鉴定及其协同增鲜效果分析

利用超滤、凝胶过滤色谱结合感官评价和电子舌分析技术,分离大球盖菇酶解液中鲜味肽组分,对鲜味最强组分F3中的鲜味肽进行反向高效液相色谱-串联质谱鉴定,并将鉴定得到的鲜味肽合成后进一步探讨其呈味特性。结果表明,大球盖菇酶解液F3组分中鉴定得到8条鲜味肽段,分别为ELWR、RLVDR、KPDNR、AHLRF、LDWDR、LAEWR、DDWWR和EGHKGW,它们均具有鲜味特征和鲜味增强作用,阈值分别为0.30~1.33mmol/L和0.53~2.43 mmol/L;除LDWDR外,7条多肽对味精溶液均有不同程度的鲜味提升,提升幅度0.18%~61.12%,ELWR、RLVDR、KPDNR、AHLRF和EGHKGW 5条多肽在低浓度时表现出良好的鲜味提升效果。RLVDR和KPDNR协同增鲜的鲜味峰值质量浓度为5mg/mL,LDWDR、LAEWR、DDWWR和EGHKGW在4mg/mL时达到鲜味峰值。鲜味肽的氨基酸组成和空间结构会影响其味觉属性。本研究结果为大球盖菇鲜味肽的开发利用提供了理论依据。

基于Lasso回归模型研究抗冻肽性质对冷冻鱼糜肌原纤维蛋白的影响

为探究抗冻肽性质对其保护冷冻鱼糜肌原纤维蛋白效果的影响,本实验对3种抗冻肽(丝胶肽、胶原肽及鲢鱼酶解产物)的性质进行表征,分析不同冻藏条件下鱼糜肌原纤维蛋白指标变化规律,并基于最小绝对缩小和选择算子(least absolute shrinkage and selection operator,Lasso)回归构建了“冻藏工艺-抗冻肽性质-肌原纤维蛋白指标”的关联模型。结果表明,所用的3种抗冻肽均为分子质量低(m<10000 Da)、亲水性强(静态接触角小于30°)的“超活性”抗冻肽(热滞活性大于0.60℃),极性氨基酸占比超过60%;所用抗冻肽能够显著减缓冻藏处理对肌原纤维蛋白的负面影响;冻藏处理后,抗冻肽组鱼糜肌原纤维蛋白含量平均值维持在50.44~54.47 mg/g,Ca^(2+)-ATPase活性平均值为1.61~1.67 U/mg,表面疏水性指数平均值相比新鲜鱼糜仅增长39.91%~42.40%,肌原纤维蛋白变性速率远低于未添加抗冻剂组。Lasso回归模型解释了抗冻肽性质对冷冻鱼糜肌原纤维蛋白变化的影响,证明低分子质量、高热滞活性的抗冻肽有助于减缓肌原纤维蛋白含量、Ca^(2+)-ATPase活性、表面疏水性及特征指数的劣变速率;抗冻肽亲/疏水性的区别导致其与冰晶和蛋白之间的相互作用不同,从而对鱼糜肌原纤维蛋白产生不同影响。本研究可为抗冻肽在冷冻鱼糜中的应用及鱼糜制品的品质调控提供理论基础,同时为研究新型高效的抗冻剂提供方向。

Purification,characterization,in vitro anti-hepatic fibrosis activity of bioactive peptides derived from Carapax Trionycis hydrolysates

Anti-hepatic fibrosis peptide from Carapax Trionycis was purified, characterized, and inhibitory effect was assessed. Carapax Trionycis extract peptide hydrolysates （CTEPHs） were separated by ultrafiltration, Sephadex G-15 gel chromatography and RP-HPLC. One novel anti-hepatic fibrosis peptide （CTEPH-I： Asn-Pro-Asn-Pro-Thr） was obtained and identified. MTS assay and enzyme-linked immunosorbent assay were applied to evaluate the anti-fibrotic effect of CTEPH-1 on activated hepatic stellate cells （HSCs） in vitro. CTEPH-1 efficiently inhibited activation and proliferation of cultured HSC-T6 cells via lowering the contents of collagen and TIMP- 1 except for matrix metalloproteinase- 1 （MMP- 1）. The purified peptide might be beneficial as functional food or potential drug for treatment of liver fibrogenesis.

酪蛋白源活性肽的微胶囊化及其对酸乳品质的影响

为提高酸乳中酪蛋白源活性肽的稳定性及功能性,以包埋率和载肽量为筛选指标,确定以海藻酸钠和蔗糖脂肪酸酯为壁材的最佳包埋方式制备酪蛋白活性肽微胶囊并应用于酸乳。结果表明:扫描电子显微镜、傅里叶变换红外光谱、X射线衍射、差示扫描量热分析显示,微胶囊能够有效包埋酪蛋白活性肽;体外缓释实验表明,微胶囊表现出良好的缓释性能,经3 h的肠道消化后胃肠联合释放率达到(62.57±1.17)%;将微胶囊化活性肽应用于酸乳加工,发现酸乳的持水性、硬度和黏性均得到改善,同时其1,1-二苯基-2-三硝基苯肼自由基清除能力达到(63.73±1.97)%,避免了乳酸菌发酵过程对酪蛋白水解肽的降解,提高了酸乳的功能性。

小麦胚芽肽和大豆酶解蛋白的体外抗氧化活性研究

试验旨在研究小麦胚芽肽和大豆酶解蛋白的分子质量分布和体外抗氧化活性。试验采用单因素完全随机设计,以维生素C为对照,分别测定小麦胚芽肽和大豆酶解蛋白在0.625、1.25、2.5、5、10 mg/mL浓度下对DPPH自由基、羟自由基和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基的清除率,并通过测定T-AOC吸光度值计算总还原力。结果表明:使用高效液相色谱测定小麦胚芽肽和大豆酶解蛋白重均分子质量分别为513 u和551 u,二者分子质量小于1000 u的比例分别为90.22%和86.93%。在一定浓度范围内,随小麦胚芽肽和大豆酶解蛋白浓度的升高,其体外抗氧化性能线性增加(P<0.05),且呈正相关关系。在10 mg/mL浓度时,小麦胚芽肽对DPPH自由基、羟自由基和ABTS自由基清除率和总还原力分别为90.39%、70.66%、96.24%和2.23,大豆酶解蛋白对DPPH自由基、羟自由基和ABTS自由基清除率和总还原力分别达到65.55%、68.21%、75.14%和0.51。综上,在本试验条件下,不同浓度小麦胚芽肽和大豆酶解蛋白均具有一定的抗氧化能力,且小麦胚芽肽相较于大豆酶解蛋白的抗氧化能力更强。

基于黄鲫蛋白肽制备南美白对虾多酚氧化酶复合生物抑制剂的研究

目的 以黄鲫蛋白肽(half-fin anchovy hydrolysate peptides,HAHp)为基料复配抗坏血酸和茶多酚制备南美白对虾多酚氧化酶(polyphenol oxidase, PPO)复合生物抑制剂(composite biological inhibitor, CBI)。方法 以南美白对虾PPO抑制率为检测指标,分别研究HAHp、抗坏血酸、茶多酚、柠檬酸和乙二胺四乙酸二钠盐(ethylenediaminetetraacetic acid disodium salt, EDTA-2Na)单独抑制PPO活性,选取HAHp、抗坏血酸和茶多酚进行三因素三水平正交优化实验优化CBI配方组成,通过酶促动力学研究CBI对南美白对虾PPO的抑制模式。结果 HAHp、抗坏血酸、茶多酚、柠檬酸和EDTA-2Na对南美白对虾PPO都有一定的抑制作用,且有一定的剂量依赖性,但单一抑制剂对PPO的抑制作用有限。HAHp与天然抗氧化剂抗坏血酸和茶多酚复配,经(L933)正交实验优化CBI的最佳配方为:0.7%HAHp、0.02%抗坏血酸和0.20%茶多酚。经测定CBI对南美白对虾PPO抑制率达到94.71%±0.46%,酶促动力学结果表明CBI是一种混合型抑制剂,通过降低南美白对虾PPO对底物亲和力实现抑制PPO活力。结论 以HAHp为基料复配抗坏血酸和茶多酚制备的CBI能够有效地抑制南美白对虾PPO活性,有望开发成一种防虾黑变的天然抑制剂,为南美白对虾天然保鲜剂的研究奠定了理论基础。

食源抗氧化肽的制备与活性筛选

过多的活性氧自由基会导致细胞凋亡甚至组织损伤,引发慢性疾病,采用食源性活性肽辅助疾病的预防和治疗具有一定的开发潜力。该研究选择α-乳白蛋白、酪蛋白、米糠蛋白、麦谷蛋白和火麻仁蛋白,进行碱性蛋白酶单酶水解、胃蛋白酶与胰液素双酶解两种方式制备抗氧化肽,并测定水解产物的抗氧化活性。结果表明,碱性蛋白酶水解条件下的样品活性更高,α-乳白蛋白、酪蛋白、米糠蛋白和麦谷蛋白水解样的抗氧化活性相近且显著高于火麻蛋白(P<0.05)。将4种抗氧化活性较高的蛋白的水解样品进行凝胶色谱分离纯化,测定活性后发现,分子质量越小的分离组分活性越高。利用液相色谱-质谱联用对抗氧化肽进行序列鉴定,获得6条三肽和5条四肽,其中WVC、LFY和YWL具有抗氧化活性潜力。