Walnut Protein Research Articles

Walnut Protein Isolate-κ-Carrageenan Composite Gels Improved with Synergetic Ultrasound-Transglutaminase: Gelation Properties and Structure

Walnut protein is a kind of natural, high-quality plant protein resource. However, its high content of gluten, strong hydrophobicity and poor gelation ability have greatly limited its development and utilization in gel products. It was found in this experiment that ultrasonic power combined with transglutaminase (TGase) had a significant effect on the gel properties of the walnut protein isolate (WNPI)-κ-carrageenan (KC) complex. The results showed that the gel strength of the WNPI-KC complex first increased and then decreased with the increase in ultrasonic power (0-400 W). WNPI-KC composite gel had the best texture properties, rheological properties, water-holding capacity (99.41 ± 0.76%), swelling ratio (2.31 ± 0.29%) and thermal stability (83.22 °C) following 200 W ultrasonic pretreatment. At this time, the gel network was more uniform and much denser, and the water molecules were more tightly bound. Further, 200 W ultrasonic pretreatment could promote the transformation of α-helices to β-folds in protein molecules, improve the fluorescence intensity, increase the content of free sulfhydryl groups and enhance the intermolecular forces. The experimental results could provide technical support for the development of walnut protein gel food.

Multi-dimensional deep learning drives efficient discovery of novel neuroprotective peptides from walnut protein isolates.

Neurodegenerative diseases, such as Alzheimer's and Parkinson's, are multi-factor induced neurological disorders that require management from multiple pathologies. The peptides from natural proteins with diverse physiological activity can be candidates as multifunctional neuroprotective agents. However, traditional methods for screening neuroprotective peptides are not only time-consuming and laborious but also poorly accurate, which makes it difficult to effectively obtain the needed peptides. In this case, a multi-dimensional deep learning model called MiCNN-LSTM was proposed to screen for multifunctional neuroprotective peptides. Compared to other multi-dimensional algorithms, MiCNN-LSTM reached a higher accuracy value of 0.850. The MiCNN-LSTM was used to acquire candidate peptides from walnut protein hydrolysis. Following molecular docking, behavioral and biochemical index experimental validation eventually found 4 hexapeptides (EYVTLK, VFPTER, EPEVLR and ELEWER) demonstrating excellent multifunctional neuroprotective properties. Therein, EPEVLR performed the best and can be investigated in depth as a multifunctional neuroprotective agent. This strategy will greatly improve the efficiency of screening multifunctional bioactive peptides, and it will be beneficial for the development of food functional peptides.

Effect of Oxidative Modification by Peroxyl Radical on the Characterization and Identification of Oxidative Aggregates and In Vitro Digestion Products of Walnut (Juglans regia L.) Protein Isolates.

Walnut protein is a key plant protein resource due to its high nutritional value, but walnuts are prone to oxidation during storage and processing. This article explored the oxidative modification and digestion mechanism of walnut protein isolates by peroxyl radical and obtained new findings. SDS-PAGE and spectral analysis were used to identify structural changes in the protein after oxidative modification, and LC-MS/MS was used to identify the digestion products. The findings demonstrated that as the AAPH concentration increased, protein carbonyl content increased from 2.36 to 5.12 nmol/mg, while free sulfhydryl content, free amino content, and surface hydrophobicity decreased from 4.30 nmol/mg, 1.47 μmol/mg, and 167.92 to 1.72 nmol/mg, 1.13 μmol/mg, and 40.93 nmol/mg, respectively. Furthermore, the result of Tricine-SDS-PAGE in vitro digestion revealed that protein oxidation could cause gastric digestion resistance and a tendency for intestinal digestion promotion. Carbonyl content increased dramatically during the early stages of gastric digestion and again after 90 min of intestine digestion, and LC-MS/MS identified the last digestive products of the stomach and intestine as essential seed storage proteins. Oxidation causes walnut proteins to form aggregates, which are then re-oxidized during digestion, and proper oxidative modification may benefit intestinal digestion.

An overview of walnuts application as a plant-based.

The plant-based refers to plant-based raw materials or products that are available as the source of protein and fat. Utilization and development of walnuts as a plant-based, resulting in a high-quality protein-rich walnut plant-based product: walnut protein powder and walnut peptides. Progress in research on the application of walnuts as a plant-based has been advanced, solving the problem of wasted resources and environmental pollution caused by the fact that walnut residue, a product of walnuts after oil extraction, is often thrown away as waste, or becomes animal feed or compost. This paper reviews and summarizes the research and reports on walnut plant-based at home and abroad, focusing on the application of walnut plant-based in the preparation process (enzymatic and fermentation methods) and the biological activity of the walnut protein and walnut peptide, to provide a theoretical basis for the further processing of walnuts as a walnut plant-based. It can make full use of walnut resources and play its nutritional and health care value, develop and build a series of walnut plant-based products, improve the competitiveness of walnut peptide products, turn them into treasure, and provide more powerful guidance for the development of food and medicine health industry in Yunnan.

Ultrasonic treatment improves physical and oxidative stabilities of walnut protein isolate-based emulsion by changing protein structure

In this study, the effect of ultrasonic, heating, and enzymatic treatments on the structural and emulsifying attributes of walnut protein isolate (WNPI) was assessed and compared. Ultrasonic, heating, and enzymatic treatments all effectively improved WNPI's emulsifying capacity and stability, especially ultrasonication. Ultrasonication (400 W, 30 min) obviously made WNPI's structure looser and more unfolded, in turn led to 1.57-fold and 2.67-fold increase in EAI and ESI of WNPI, respectively. Besides, the exposure of WNPI′ hydrophobic groups induced by sonication, reflected in a 3.64-fold increase in WNPI's surface hydrophobicity, may also contributes to the increase of WNPI's emulsifying properties. Furthermore, the emulsion stabilized by UT-WNPI exhibited the best lipid and protein oxidative stabilities during storage at 55 °C for 7 days. Compared to emulsion stabilized by the untreated WNPI, hydroperoxide, TBARS, and protein carbonyl contents in the emulsion stabilized by UT-WNPI decreased by 46.92%, 40.74%, and 33.89%, respectively. Our results clarify ultrasonication is the best for improving the emulsifying properties of walnut protein, thereby broadening walnut protein's application in the emulsified food.

Purification, Identification and Molecular Docking of Novel Antioxidant Peptides from Walnut (Juglans regia L.) Protein Hydrolysates

Walnut protein isolate (WPI) was hydrolyzed using Alcalase for 0, 30, 60, 90, 120 and 150 min to investigate the effect of different hydrolysis times on the structure and antioxidant properties of walnut proteins. The identified peptides HADMVFY, NHCQYYL, NLFHKRP and PSYQPTP were used to investigate the structure-activity relationship by using LC-MS/MS and molecular docking. The kinetic equations DH = 3.72ln [1 + (6.68 E0/S0 + 0.08) t] were developed and validated to explore the mechanism of WIP hydrolysis by Alcalase. Structural characteristics showed that the UV fluorescence intensity and endogenous fluorescence intensity of the hydrolysates were significantly higher than those of the control. FTIR results suggested that the secondary structure gradually shifted from an ordered to a disordered structure. Enzymatic hydrolysis containing much smaller molecule peptides than WPI was observed by molecular weight distribution. In vitro, an antioxidant test indicated that Alcalase protease hydrolysis at 120 min showed more potent antioxidant activity than hydrolysates at other hydrolysis times. In addition, four new antioxidant peptides were identified by LC-MS/MS. Molecular docking indicated that these peptides could interact with ABTS through interactions such as hydrogen bonding and hydrophobic interactions. Thus, WPI hydrolysates could be used as potential antioxidants in the food and pharmaceutical industries.

Phenolic compounds in walnut pellicle improve walnut (Juglans regia L.) protein solubility under pH-shifting condition

This study focused on the interaction of walnut protein with phenolic extracts of walnut pellicle (PEWP) under alkaline condition, leading to enhancement of protein solubility under neutral condition. First, the change of PEWP under alkaline condition was determined by RP-HPLC and mass spectrometry, and the results showed that most ellagitannins in PEWP could be retained under alkaline condition within 3 h. Interaction between PEWP and walnut protein under pH-shifting condition resulted in the remarkable increase of protein solubility (above 90%) at neutral pH. The results from SDS-PAGE and SEC showed that the improved solubility lied in the formation of large and soluble protein aggregates due to the covalent interaction among walnut protein and polyphenols. A significant change in tertiary structure of protein–phenolic complex was witnessed by fluorescence spectrum and near-UV circular dichroism. Meanwhile, walnut protein–polyphenol interaction led to a slight increase in β-turn while a slight decrease in β-sheet. Combined with amino acid composition, it could be illustrated that the covalent bonding for walnut protein with polyphenol mainly occurred at Lysine residues.

Nutritional Evaluation of Walnut Protein and Its Ameliorative Effect on DSS Induced Acute Colitis in Mice

Nutritional Evaluation of Walnut Protein and Its Ameliorative Effect on DSS Induced Acute Colitis in Mice

Novel angiotensin I-converting enzyme (ACE) inhibitory peptides from walnut protein isolate: Separation, identification and molecular docking study.

Walnut protein isolate was hydrolyzed using alcalase® to obtain angiotensin-I-converting enzyme (ACE) inhibitory (ACEI) peptides. The components with high ACEI activity were successfully purified from walnut protein isolate hydrolysates (WPIH) by ultrafiltration and G-25 gel chromatography. The 1520 peptides were identified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Then the screening model of ACEI peptides was established by in silico approach. It was found that four ACEI active peptides (PPKP, YPQY, YLPP, and PKPP) were obtained with IC50 values ranging from 506 to 89 μmol/L, among which PPKP had the highest ACEI activity (IC50 =89 ± 1μmol/L). The four peptides mentioned above were novel, non-toxic, and resistant to gastrointestinal digestion. The molecular docking studies showed that the ACEI effect of ACEI peptide was mainly due to the interaction with residues of Gln281 and His353 in the ACE active pockets. In vivo availability of ACEI peptides showed that the probability of PPKP binding to ACE was 37.9% in the human body. Our studies suggest that the ACEI peptides derived from the WPIH can be considered functional foods that can prevent hypertension. PRACTICAL APPLICATIONS: Hypertension is a significant risk factor for cardiovascular and cerebrovascular disease, the leading cause of death worldwide. This study used a cost-effective method to isolate and identify potential ACEI peptides from the walnut meal. Since the walnut meal is often discarded in the processing of walnut products and thus pollutes the environment, the preparation of walnut meal into ACEI peptides can reduce the impact of hypertension on people and reduce environmental pollution. The experimental results show that walnut ACEI peptides are a safe and healthy nutritional product.

Arginine-Containing Peptides Derived from Walnut Protein Against Cognitive and Memory Impairment in Scopolamine-Induced Zebrafish: Design, Release, and Neuroprotection.

The purpose of this study was to investigate the neuroprotective effect of Arg-containing peptides from walnut storage protein sequences in scopolamine-induced zebrafish and further to validate the potential neuroprotection of Arg-containing peptide enriched walnut hydrolysates prepared by in silico hydrolysis and controlled enzymatic release. Results showed that walnut derived Arg-containing peptides with high abundance and great bioactivity predicted by bioinformatics displayed potent neuroprotection in scopolamine-induced zebrafish, and regulation of neurotransmitter level and antioxidant enzyme activity might be the main target for Arg-containing peptides to exert neuroprotection. Notably, Arg-containing peptides (not free arginine) contributed greater neuroprotection, and the positive charge and cell-penetrating properties also affected their neuroprotection. Subsequently, Arg-containing peptides could be released efficiently from walnut protein following hydrolysis by trypsin, pepsin, papain, and thermolysin (bound arginine content: ranging from 110.43 ± 1.58 to 121.82 ± 1.02 mg/g). Among them, trypsin had excellent potential for releasing Arg-containing peptides in silico hydrolysis, and its hydrolysate was confirmed to have neuroprotective capacity, indicating that the combination of in silico hydrolysis and controlled enzymatic release might be an effective approach to obtain Arg-containing neuroprotective peptides.

The effects of conjugation of walnut protein isolate with polyphenols on protein solubility, antioxidant activity, and emulsifying properties

Alkaline-extracted walnut protein isolate (AWPI) shows poor solubility in aqueous solutions, resulting in relatively low emulsion capacity. This work investigated the influence of ellagic acid (EA) or epigallocatechin-3-gallate (EGCG) conjugation on the solubility and emulsifying properties of AWPI. The increase in polyphenol content and decrease in free amino and thiol groups of walnut proteins confirmed successful conjugation. AWPI polyphenol conjugates showed significantly reduced surface hydrophobicity, greatly enhanced surface charge, and consequently improved solubility. Circular dichroism (CD) results indicated that the polyphenol-conjugated AWPI contained relatively higher α-helical and lower β-sheet contents than AWPI. The antioxidant capacity of the polyphenol-conjugated AWPI was significantly enhanced. Additionally, polyphenol conjugation resulted in decreased mean particle sizes and increased surface charges of the walnut protein-covered oil droplets. The emulsions stabilized by AWPI-polyphenol conjugates were relatively more stable over a range of pH values (7.0–11.0) and thermal treatments (25 °C–90 °C). Moreover, they exhibited greater storage stability than those stabilized by unmodified AWPI.

Effects of Oxidation Modification by Malondialdehyde on the Structure and Functional Properties of Walnut Protein.

(1) Background: The effects of protein oxidization induced by malondialdehyde (MDA), which was selected as a representative of lipid peroxidation products, on the structure and functional properties of walnut protein were investigated. (2) Methods: Walnut protein isolate was produced by alkali-soluble acid precipitation. The modification of walnut protein isolate was conducted by MDA solutions (0, 0.01, 0.1, 1, and 10 Mm), which were incubated in the dark for 24 h. (3) Results: Increased carbonyl content and the degradation of sulfhydryl groups indicated MDA-induced protein oxidization. The circular dichroism spectra revealed disruption of the ordered protein secondary structure. The change in the tertiary conformation of the MDA-treated protein was observed through intrinsic fluorescence. Small polypeptide chain scission was observed at low MDA concentrations (≤0.1 mM) and protein aggregation was observed at high MDA concentrations (>0.1 mM) using high-performance size exclusion chromatography. Oxidized protein solubility was reduced. Furthermore, the emulsification stability index, foam capacity, and foam stability of walnut proteins were increased after treatment with 0.1 mM of MDA. An excessive concentration of MDA (>0.1 mM) decreased emulsification and foaming properties. (4) Conclusions: These results show that MDA oxidation modified the structure of walnut protein and further affected its function, which should be taken into account in processing walnut protein products.

Multi-mode S-type ultrasound-assisted protein extraction from walnut dregs and in situ real-time process monitoring

This study aimed to investigate the impact of multi-mode S-type ultrasound treatment on the protein extraction level of walnut dregs. The structural properties of the walnut protein (WP) were characterized, and the correlation between protein structure and extraction level was analyzed. The in situ real-time monitoring model for the ultrasound-assisted WP extraction process was established by a miniature fiber near-infrared (NIR) spectrometer. Results showed that the protein yield, purity, and comprehensive extraction index (CEI) of extracted WP were 71.07 %, 72.69 %, and 71.72, respectively, under optimal conditions (dual-frequency 20/28 kHz, ultrasonic treatment duration 30 min, and ultrasound power density 120 W/L). The secondary structure of extracted WP displayed that the proportion of α-helix and β-sheet reduced, while the contents of β-turn and random coil increased after ultrasonic treatment. Besides, sonication decreased the disulfide bond content and increased free sulfhydryl (-SH) and surface hydrophobicity compared to the control. The microstructures of WP confirmed that appropriate sonication could unfold the protein aggregates and reduce the particle size. The extraction level of WP is positively correlated with the -SH content (p < 0.01). The quantitative prediction model of Si-PLS for -SH content in the ultrasound-assisted WP extraction process was established and performed a good correction and prediction performance (Rc = 0.9736; RMSECV = 0.446 μmol/L; Rp = 0.9342; RMSEP = 0.807 μmol/L). This study exploited a high-efficiency way for the WP extraction industry, and provided theoretical support for the development of the intelligent system in industrial protein extraction process.

Quantification of Vitamins, Minerals, and Amino Acids in Black Walnut (Juglans nigra)

This paper aims to quantify the micronutrients in black walnut and address its human health benefits. The metabolic profiling of 11 black walnut cultivars was accomplished using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometer. Results revealed that the highest concentration of vitamin B9 was present in cultivar “Daniel” (avg. relative signal intensity 229.53 × 104 mAU). “Surprise” and “Daniel” cultivars had the highest amount of vitamin B5. However, vitamin A, D3, E, and K showed no significant difference among the cultivars. The vitamin content levels among the cultivars were compared by applying one way ANOVA method with (P < 0.05) significance level. Mineral analysis for the black walnut kernel, Persian walnut, and black walnut protein powder was done using Inductively Coupled Plasma Optical Emission spectroscopy. The experimental data for black walnut kernel is 0.04 mg/g for Fe and 0.03 mg/g for Zn, and for black walnut, protein powder is 0.07 mg/g for Fe and 0.07 mg/g for Zn. The amino acid analysis and comparison with black walnut kernel show that black walnut flour and protein powder have a higher amount of essential and non-essential amino acids. Therefore, researchers, food process engineers, and food product developers should consider the health benefits of black walnuts and explore the commercial potential of this native agroforestry crop.

The effect of plant-derived peptides on the hot-melt stickiness of herbal extracts during spray drying

The aim of this study was to explore plant-derived peptides as carrier material with the function of anti-hot-melt stickiness of traditional Chinese herbal extracts during spray drying. Crataegi fructus extract (CFE) with a severe hot-melt stickiness problem was used as a model drug, and soy peptides (SPT) were screened as the most effective and suitable carrier material among seven plant-derived proteins and peptides which include soy protein isolate, walnut protein and five kinds of peptides (corn peptides, wheat peptides, walnut peptides, rice peptides and SPT). The addition of 15% SPT also exhibited a strong anti-stickiness effect in other four hot-melt sticky herbal extracts from Chinese herbs (Lycii fructus, Corni fructus, Chaenomelis fructus and Mume fructus) since the obtained powder increased from completely sticking to the wall to more than 50% powder yield. The dynamic surface tensions (DST) of CFE decreased consistently with the increase of SPT from 5% to 20%, and DST1000ms had consistent reduction with the addition of SPT from zero to 20%. Meanwhile, the adhesive force of the single droplet at 28 min decreased below 18.5 N. The softening point of the spray-dried powder of CFE added 15% SPT increased by about 40 °C, and the addition of 15% SPT improved the stability which might be similar with the addition of 50% MD based on scanning electron microscope analysis but more efficiently. These findings confirmed that SPT plant-derived could serve as effective and stable carrier material with good anti-stickiness ability during spray drying.

Extraction optimization and antioxidant activity evaluation of se‐enriched walnut proteins

In this study, the proteins of selenium-enriched walnuts produced in three seleniferous areas of Enshi (Yesanguan (YS), Lichuan (LC), and Sancha (SC)) were extracted by the alkaline method. Response surface methodology (RSM) was used for the optimization of protein extraction. The total selenium (Se) content of walnut proteins was 1.3345 mg/kg in YS, 0.6219 mg/kg in LC, and 0.4219 mg/kg in SC, and about 82–85% was organic Se. The major Se speciation was selenocystine and selenomethionine. All walnut proteins showed antioxidant activities in a Se-concentration-dependent manner. The antioxidant activity of YS walnut was stronger than that of other proteins, which exhibited high DPPH radical (69.5%) and moderate hydroxyl radical (46.5%) scavenging activities at 1.0 mg/ml. After enzymatic hydrolysis, protein hydrolysates displayed significantly higher antioxidant capacities than undigested proteins at all tested concentrations. The overall results indicated that Se-enriched walnuts have great potential as functional food additives for a dietary supplement. Novelty impact statement Organic selenium accounts for more than 82% of the total Se in walnut proteins, in which SeCys2 and SeMet are major organic forms of selenium. The Se content in walnut proteins is positively correlated with the antioxidant ability. Walnut protein hydrolysates exhibit better antioxidant activities than proteins.

De Novo Arginine Synthesis Is Required for Full Virulence of Xanthomonas arboricola pv. juglandis During Walnut Bacterial Blight Disease.

Walnut blight (WB) disease caused by Xanthomonas arboricola pv. juglandis (Xaj) threatens orchards worldwide. Nitrogen metabolism in this bacterial pathogen is dependent on arginine, a nitrogen-enriched amino acid that can either be synthesized or provided by the plant host. The arginine biosynthetic pathway uses argininosuccinate synthase (argG), associated with increased bacterial virulence. We examined the effects of bacterial arginine and nitrogen metabolism on the plant response during WB by proteomic analysis of the mutant strain Xaj argG-. Phenotypically, the mutant strain produced 42% fewer symptoms and survived in the plant tissue with 2.5-fold reduced growth compared with wild type, while showing itself to be auxotrophic for arginine invitro. Proteomic analysis of infected tissue enabled the profiling of 676 Xaj proteins and 3,296 walnut proteins using isobaric labeling in a data-dependent acquisition approach. Comparative analysis of differentially expressed proteins revealed distinct plant responses. Xaj wild type (WT) triggered processes of catabolism and oxidative stress in the host under observed disease symptoms, while most of the host biosynthetic processes triggered by Xaj WT were inhibited during Xaj argG- infection. Overall, the Xaj proteins revealed a drastic shift in carbon and energy management induced by disruption of nitrogen metabolism while the top differentially expressed proteins included a Fis transcriptional regulator and a peptidyl-prolyl isomerase. Our results show the critical role of de novo arginine biosynthesis to sustain virulence and minimal growth during WB. This study is timely and critical as copper-based control methods are losing their effectiveness, and new sustainable methods are urgently needed in orchard environments.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Phosphorylated walnut protein isolate as a nanocarrier for enhanced water solubility and stability of curcumin

The low solubility and poor dispersion of alkaline-extracted walnut protein isolate (AWPI) limit its application as a protein-based carrier for the delivery of poorly soluble nutraceuticals, including curcumin. This work investigated the physicochemical characteristics of phosphorylated walnut protein isolate (PWPI) extracted using sodium tripolyphosphate (STP) and evaluated its encapsulation ability. The results of phosphorus determination, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy confirmed the phosphorylation of the extracted PWPI. Circular dichroism (CD) analysis indicated that PWPI contained higher α-helix and lower β-sheet contents than AWPI. The PWPI prepared at pH 9.0 and 11.0 showed significantly improved solubility, similar surface hydrophobicity, and increased surface charges compared to the AWPI. Fluorescence quenching experiments indicated that the binding affinity of curcumin to PWPI was significantly higher than that of AWPI. When bound to PWPI, the solubility of curcumin in aqueous solution was greatly enhanced, with an 8,700-fold increase at a nanocomplex concentration of 10 mg/mL. The complexation of curcumin with PWPI significantly improved the storage stability of curcumin. Additionally, the PWPI-curcumin nanocomplexes showed significantly increased antioxidant capacity. Phosphorylated walnut protein isolate showed greatly improved solubility and strong encapsulation ability, making it a promising nanocarrier for curcumin. This article is protected by copyright. All rights reserved.

Effect of NaCl on the Rheological, Structural, and Gelling Properties of Walnut Protein Isolate-κ-Carrageenan Composite Gels.

In this study, we discovered that a certain concentration of Na+ (15 mM) significantly improved the bond strength (12.94 ± 0.93 MPa), thermal stability (72.68 °C), rheological properties, and textural attributes of walnut protein isolate (WNPI)-κ-carrageenan (KC) composite gel. Electrostatic force, hydrophobic interaction, hydrogen bond, and disulfide bond were also significantly strengthened; the α-helix decreased, and the β-sheet increased in the secondary structure, indicating that the protein molecules in the gel system aggregated in an orderly manner, which led to a much denser and more uniform gel network as well as improved water-holding capacity. In this experimental research, we developed a new type of walnut protein gel that could provide technical support for the high-value utilization and quality control of walnut protein.

A Two-Stage Enzymolysis Method and Its Application in Exerting Antioxidant Activity of Walnut Protein.

Traditional enzymolysis method for producing bioactive peptides does not consider the utilization of digestive enzymes in the human gastrointestinal tract, leading to the possibility of excessive hydrolysis and higher production cost. Therefore, a two-stage enzymolysis method was established in this study based on in vitro limited enzymolysis and gastrointestinal digestion, and applied it to the research of walnut protein (WP) in exerting antioxidant activity. Results showed that WP could be well-digested by pepsin and pancreatin. WP with limited enzymolysis degree of 0% could achieve high antioxidant activity after the simulated gastrointestinal digestion, and the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power were 66.53% and 8.55 μmoL TE/mL, respectively. In vivo experimental results also exhibited that both WP and WP hydrolysate (WPH) could alleviate the oxidative damage induced by D-galactose in SD rats to some extent. Considering the digestive function of human body, in vitro limited enzymolysis, in vitro simulated gastrointestinal digestion and in vivo validation are necessary processes for the production of bioactive peptides.