Production and characterisation of duck albumen hydrolysate using enzymatic process

Influences of different ultrasound treatments combined with heat pretreatment on enzymatic hydrolysis, emulsifying properties and antioxidant activities of hydrolysates from duck egg albumen were studied. Heat pretreatment at 95 °C for 30 min inhibited both serine and cysteine protease inhibitors effectively. Ultrasonication of heated duck albumen at 60% amplitude for 10 min yielded the highest surface hydrophobicity. Coincidentally, aforementioned pretreatment rendered the hydrolysate with highest degree of hydrolysis (DH) than other pretreatments when Alcalase was used. The resulting hydrolysate showed the highest antioxidant activities including DPPH radical and ABTS radical cation scavenging activities and ferric reducing antioxidant power as well as emulsifying properties when hydrolysis time of 90 min was used. The hydrolysate possessed the peptides with molecular weight of 219–255 Da with the highest ABTS radical scavenging activity. Thus, heat pretreatment, followed by ultrasonication of duck albumen under appropriate condition could increase DH, antioxidant activities and emulsifying properties of duck albumen hydrolysate.     

Effects of sweeping frequency ultrasound treatment on enzymatic preparations of ACE-inhibitory peptides from zein

In this study, the effect of sweeping frequency ultrasound (SFU) treatment on the degree of hydrolysis of zein and the angiotensin I-converting enzyme (ACE)-inhibitory activity of its hydrolysates were investigated. The mechanism through which ultrasonic pretreatment releases peptides with ACE-inhibitory activity was also studied by fluorescence, circular dichroism (CD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Compared to the control, SFU and fixed frequency ultrasound (FFU) increased the degree of zein hydrolysis by approximately 11.5 %. Sweeping frequency ultrasound pretreatment increased ACE-inhibitory activity of zein hydrolysates by 12.3–116.7 % over the control. At 40 ± 2 kHz, SFU-treated zein hydrolysates had 42.9 % ACE-inhibitory activity, representing an increase of 116.7 % over the control. The fluorescence intensity of SFU- and FFU-treated zein was weaker than in untreated zein, indicating that more Phe, Trp, and Tyr residues were exposed outside the polypeptide chains. CD spectra show that SFU treatment resulted in increase in the α-helix content by 3.4 %, and β-sheet, β-turns, and random coils content by 24.4 %. Analyses of microstructure by SEM and AFM revealed that ultrasonic pretreatment ruptured the fine meshwork structure of zein resulting in the appearance of several micro-holes. We conclude that the SFU pretreatment for 40 ± 2 kHz can remarkably raise the degree of zein hydrolysis and ACE-inhibitory activity of the hydrolysates by altering the second structure of zein and rupturing the smooth surface of protein.     

Proteolysis characteristics of sarcoplasmic, myofibrillar, and stromal proteins separated from grass carp and antioxidant properties of their hydrolysates

Proteolysis of grass carp sarcoplasmic, myofibrillar, and stromal proteins by 5 commercial proteases were studied. Sarcoplasmic and myofibrillar protein could be well hydrolyzed by Alcalase 2.4 L to reach high protein recoveries (PR) (71.86±2.46 and 80.77±3.05%, respectively), while the maximum PR for stromal protein was only 42.83±2.84%. However, stromal hydrolysates, containing mostly 6–10 kDa fraction, exhibited higher ·OH scavenging activities due to its high content of antioxidant-assisting amino acids. Alcalase 2.4 L and pancreatin 6.0, which produced hydrolysates with relative high degree of hydrolysis (DH), were used for further hydrolysis of whole grass carp protein with the assistance of response surface methodology (RSM). The results showed that serine proteases (Alcalase 2.4 L and pancreatin 6.0) could produce sarcoplasmic, myofibrillar, or stromal hydrolysates with relatively high PR, DH, and strong ·OH scavenging activity, which may be used to prepare antioxidant hydrolysates from grass carp.     

Preparation of antioxidant peptide from egg white protein and improvement of its activities assisted by high-intensity pulsed electric field

BACKGROUND: Egg white protein powder was hydrolyzed by three proteases—alcalase, trypsin, and pepsin—to produce antioxidant peptides. Three kinds of hydrolysates were prepared under optimal enzymatic parameters that were obtained from the preliminary one‐factor‐at‐a‐time test and response surface methodology. Thereafter, three enzymatic hydrolysates were sequentially fractionated by ultrafiltration membranes in cut‐off MW of 30, 10, and 1 kDa, and tested in terms of their reducing power (RP). Effects of high‐intensity pulsed electric field (PEF) were further investigated on the antioxidant peptides to improve their activities. RESULTS: Alcalase hydrolysates possessed stronger RP ability than the other two hydrolysates, particularly for the fraction within < 1 kDa. After PEF treatment, this fraction showed an improvement of RP ability within 4 h; however, the effects were reversible. High‐performance liquid chromatographic analysis showed some MW changes of PEF‐treated sample compared with control. CONCLUSIONS: Among the three kinds of proteases, alcalase could be regarded as the most appropriate enzyme for preparation of bioactive peptide from egg white protein, with the best antioxidant activity. Also, PEF showed some effects on the peptide and could be further applied to improve its antioxidant activity. Copyright © 2011 Society of Chemical Industry     

Bioactive properties of Kilka (<Emphasis Type="Italic">Clupeonella cultriventris caspi</Emphasis>) fish protein hydrolysates

Whole common Kilka fish was hydrolyzed separately using four commercial enzymes, Alcalase, Neutrase, Protamex at 50 °C and Pepsin at 37 °C for 30, 60 and 90 min. Degree of hydrolysis, angiotensin-I-converting enzyme (ACE) inhibitory activity and antimicrobial activity of each hydrolysate against Gram-negative (Escherichia coli, Salmonella enteritidis) and Gram-positive (Staphylococcus aureus, Listeria innocua) bacteria were studied. Results showed that the degree of hydrolysis for all enzymes was in the range of 2.63–3.36%. Electrophoresis profiles of the Kilka protein hydrolysates showed that most of produced peptides were in the range of 30 D but Alcalase and Neutrase had a better performance in the production of low molecular weight peptides in the range of 10 D. This led to increase the antimicrobial activity against the examined bacteria at the concentration of 200 µg/mL peptide solution. The Neutrase enzyme produced hydrolysate with the highest ACE inhibitory activity (53%?±?1.8 at 500 µg/mL). Antimicrobial activity of Kilka protein hydrolysates using Protamex and Pepsin was lower than the others due to lack of considerable amount of small peptides. The current research has demonstrated that the peptides derived from the enzymatic hydrolysis of Kilka fish protein in optimum conditions are capable of being converted to antimicrobial and antihypertensive agents to be used in functional foods.     

Hydrolysis conditions for antioxidant peptides derived from enzymatic hydrolysates of sandfish (<Emphasis Type="Italic">Arctoscopus japonicus</Emphasis>)

Sandfish (Arctoscopus japonicus) meat and roe were used as natural materials for the preparation of antioxidant peptides using enzymatic hydrolysis. Meat and roe were hydrolyzed using Alcalase 2.4 L and Collupulin MG, respectively. Optimal hydrolysis conditions were determined through the effects of pH, temperature, enzyme concentration, and hydrolysis time on the radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH). The optimal hydrolysis conditions for meat hydrolysate (MHA) obtained via Alcalase 2.4 L treatment were a pH of 6.0, temperature of 70 °C, enzyme concentration of 5% (w/w), and a hydrolysis time of 3 h. The optimal hydrolysis conditions for roe hydrolysate (RHC) obtained via Collupulin MG treatment were pH 9.0, 60 °C temperature, 5% (w/w) enzyme concentration, and 1 h hydrolysis time. Under the optimal conditions, the DPPH radical scavenging activities of MHA and RHC were 60.04 and 79.65%, respectively. These results provide fundamental data for the production of antioxidant peptides derived from sandfish hydrolysates.     

超声预处理对玉米蛋白可酶解性的影响

旨在采用超声预处理改善玉米蛋白的酶解性,研究了超声频率模式(单频、双频、定频和扫频)及频率参数对玉米蛋白酶解水解度及溶解率的影响,采用高效尺寸排阻色谱法对酶解液的分子质量分布进行了表征。研究发现,(68±2)kHz/(28±2)kHz双频扫频为最佳超声频率模式,优化试验获得超声预处理的最佳工作参数为:超声温度30℃、料液比1:20(g/mL)、超声处理时间40 min、扫频周期500 ms、超声功率密度80 W/L、脉冲超声的工作时间10 s和间歇时间3 s。在最佳超声频率模式及工作参数预处理的条件下,水解度和蛋白溶解率分别为23.6%和75.2%,较对照组(未经超声处理)分别提高了39.4%和54.7%,且酶解液具有更窄的分子质量分布范围。这表明超声预处理能促进玉米蛋白向多肽转化,尤其有利于分子质量为200~1 000 u的玉米蛋白肽的形成。     

Effect of Microwave Treatments on Antioxidant Activity and Antigenicity of Fish Frame Protein Hydrolysates

Protein solubility, protein recovery, antioxidant activity, and antigenicity of microwave pretreatment and/or microwave-assisted hydrolysis of trout frame protein hydrolysates was investigated. Treatments consisted of (1) microwave pretreatment at low temperature (55 °C) followed by conventional enzymatic hydrolysis or (2) high temperature (90 °C) followed by conventional enzymatic hydrolysis; (3) microwave pretreatment at high temperature (90 °C) followed by microwave-assisted enzymatic hydrolysis, and (4) no microwave pretreatment followed by microwave-assisted enzymatic hydrolysis. Compared to controls, microwave treatments significantly improved (P < 0.05) protein solubility, protein recovery, degree of hydrolysis, and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) free radical scavenging radical scavenging activity. Decrease of antigenicity (55–93 %) was obtained in all microwave-treated samples. Based on the results of this study, the use of microwave pretreatment for 5 min at 90 °C, followed by conventional enzymatic hydrolysis with alcalase for 2–10 min was the best treatment condition to produce fish peptides with antioxidant activity and the lowest immunoreactivity. These peptides have potential to be applied as hypoallergenic ingredients in food formulations and nutraceuticals.     

Recovery of protein hydrolysates from brewer’s spent grain using enzyme and ultrasonication

The aim of this study was to develop a green ultrasound-assisted enzymatic process to separate protein from brewer’s spent grain (BSG) to produce protein hydrolysates and determine the physicochemical properties of produced protein hydrolysates. When the enzyme (Alcalase) loading increased from 1 to 20 μL g⁻¹ BSG, the protein separation efficiency increased from 34.0% to 61.6%. The application of ultrasound pretreatment further increased protein separation efficiency to 69.8%. More promisingly, the ultrasound pretreatment was able to reduce enzyme loading by 73% and decrease enzyme incubation time by 56%. The produced protein hydrolysates had molecular weights lower than 15 kDa and high protein solubilities at the pH of 1.0–11.0. The ultrasound pretreatment improved the protein solubility to above 90%. Glutamic acid and proline were the most abundant amino acids in produced protein hydrolysates. This study demonstrated that enzymatic hydrolysis along with ultrasound pretreatment is an effective way to separate protein from BSG.     

Production and characterisation of antioxidant peptides from sweet potato protein by enzymatic hydrolysis with radio frequency pretreatment

Effect of radio frequency (RF at 70, 80 and 90 °C) pretreatment on production and characterisation of sweet potato protein hydrolysates (SPPH) prepared using Alcalase (ALC), Protease (PRO) and the combination of ALC + PRO was investigated. RF highly improved degree of hydrolysis (DH) and enhanced antioxidant activity of all SPPH produced by ALC, PRO and the combination as compared to traditional water bath (WB) heating pretreatment (P < 0.05). RF significantly increased molecular weight (MW) <3 kDa peptide fraction from SPPH produced by ALC, and MW <3 kDa peptide fraction from RF80- and RF90-pretreated samples has higher antioxidant activity. Diverse peptides in MW <3 kDa fractions with RF80 and RF90 pretreatments were identified using LC–QTOF–MS/MS, which matched the sequences of sporamins and contained antioxidant amino acids Trp, Tyr, Met, Phe and/or His. There is a great potential application of using SPPH in functional foods as a novel ingredient.     

Calcium-binding peptides derived from tilapia (Oreochromis niloticus) protein hydrolysate

Calcium-binding peptide was derived from protein hydrolysates. In this study, tilapia protein at a concentration of 2 % (w/v) was hydrolyzed using various proteases including Alcalase 2.4 L, Flavourzyme 1,000L, Protease GN, and papain at 50 °C, pH 8 for 6 h. It was found that the degree of hydrolysis increased with the time of the incubation in all cases. The highest calcium-binding capacity of the hydrolysate was 65 mg/g protein at 27.7 % degree of hydrolysis by Alcalase 2.4 L. The molecular weight of the calcium-binding peptides characterized by gel-filtration chromatography on a Sephadex G-25 was 1.2 kDa. The calcium-binding motif of the hydrolyzed peptides identified by the automated Edman degradation was a short peptide (Trp-Glu-Trp-Leu-His-Tyr-Trp). The results of this study suggested that tilapia protein is a good source for calcium-binding peptides.     

不同苦荞蛋白酶解产物抗氧化活性研究

以苦荞蛋白作为底物,采用碱性蛋白酶Alcalase 2.4 L、木瓜蛋白酶、胃蛋白酶、胰蛋白酶以及胃蛋白酶加胰蛋白酶模拟体内蛋白消化,制备苦荞麦蛋白水解物。采用DPPH及ABTS~+·法比较不同的蛋白水解物与水解前苦荞蛋白的体外抗氧化活性。结果表明:不同蛋白酶水解产物水解度由高到低的顺序为:碱性蛋白酶胃蛋白酶~胰蛋白酶胃蛋白酶木瓜蛋白酶胰蛋白酶,其中碱性蛋白酶水解苦荞蛋白水解度达29.95%。苦荞蛋白本身具有一定的抗氧化能力,其中DPPH清除率及ABTS~+·清除率最高分别达71.91%及11.25%,但均显著低于阳性对照Vc。随着水解程度的增加,苦荞蛋白水解产物抗氧化能力逐渐增强。其中,以碱性蛋白酶酶解产物抗氧化活性最高,其DPPH清除率及ABTS~+·清除率最高分别为91.65%(0.5 mg/mL)及16.67%(1 mg/mL),均显著高于原苦荞蛋白。其中,碱性蛋白酶水解产物的DPPH自由基清除率在高浓度(0.5mg/mL)条件下,与阳性对照Vc持平。同时碱性蛋白酶酶解产物抗氧化性(DPPH清除率及ABTS~+·清除率)显著优于其他蛋白酶解产物。因此,苦荞麦蛋白采用碱性蛋白酶解制备苦荞水解产物可作为天然的抗氧化剂。     

Functional Properties and Bioactivities of Pine Nut (Pinus gerardiana) Protein Isolates and Its Enzymatic Hydrolysates

The functional properties and bioactivities of the pine nut protein isolates (PPI) and its enzymatic hydrolysates (PPH) prepared with Alcalase at 5 %, 10 %, 15 % and 25 % degree of hydrolysis (DH) were studied. The solubility of PPH significantly increased (p?<?0.05) with the increase of the DH, while the foaming capacity of PPH was only improved at a low DH. However, enzymatic hydrolysis reduced the emulsifying capacity of PPH. The DPPH radical scavenging and inhibition of linoleic acid oxidation activities of PPH were significantly improved by a low DH (5 %) compared with those of PPH with a higher DH and the original PPI (p?<?0.05). The reducing power of PPH at all DH decreased in comparison to that of the original PPI. Potent angiotensin-converting enzyme (ACE) inhibitory peptides could be generated by hydrolysis with Alcalase, and the ACE inhibitory activity of PPH increased (p?<?0.05) with the DH. These results revealed that a low degree of enzymatic hydrolysis was appropriate to obtain PPH with improved functional properties and good antioxidant activities, while a high degree of hydrolysis was essential to obtain highly potent ACE inhibitory peptides from PPI. These results suggest that the control of the DH may be an effective strategy to modify specific functional and bioactive properties of PPH, and PPH has potential as a functional food ingredient for related functional and health benefits.     

Evaluation of free radical‐scavenging activities of sweet potato protein and its hydrolysates as affected by single and combination of enzyme systems

To evaluate the free radical‐scavenging activities of sweet potato protein (SPP) and its hydrolysates, single enzymes alone (alcalase, neutrase, protamex) or in combination with flavourzyme were employed. Compared with SPP, free radical‐scavenging activities of the resulting hydrolysates were all significantly increased (P < 0.05). Alcalase (ALC) hydrolysates exhibited the highest superoxide, hydroxyl and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activities (P < 0.05), which was 18.71 ± 0.22, 27.13 ± 0.24 and 90.10 ± 0.15% respectively. Compared with SPP hydrolysates by single enzymes, the hydrolysates obtained by combination of enzyme systems exhibited higher degree of hydrolysis, but lower free radicals scavenging activities. In addition, the content of several antioxidant amino acid residues, such as His, Met, Tyr and Phe, in ALC hydrolysates was much higher compared with SPP and other hydrolysates using amino acids composition assay. The results suggested that peptides with free radical‐scavenging activity could be released from entire SPP chain via moderate enzymatic hydrolysis.     

Amino acid composition,antioxidant and functional properties of protein hydrolysates from the roe of rainbow trout (Oncorhynchus mykiss)

A fish roe protein hydrolysate from rainbow trout (Oncorhynchus mykiss) trout roe protein hydrolysates (TRH) was produced by pepsin and Alcalase. Proximate, amino acid compositions, protein digestibility and molecular mass distribution of the hydrolysates were determined. The degree of hydrolysis was found to be 44.08% and 27.62% (pepsin and Alcalase, respectively). The two hydrolysates contained a high amount of essential amino acids (33.53% Alcalase–29.39% pepsin). The results showed that TRH by different enzymes is a good source of the leucine and lysine amino acids. The pepsin produced a white powder with higher brightness (L* = 89.50). Alcalase hydrolysate was brownish yellow in colour (L* = 52.85, a* = 10.30, b* = 26.25). The hydrolysates represented excellent antioxidant activities in various concentrations. TRHs showed a good foaming and emulsification properties. The results thus revealed that protein hydrolysates from rainbow trout roe could be used as food additives possessing essential amino acids and antioxidant activity.     

Biochemical properties and antioxidant activity of myofibrillar protein hydrolysates obtained from patin (Pangasius sutchi)

Antioxidant activities of myofibrillar protein hydrolysates (MPH) prepared from patin (Pangasius sutchi) using papain and Alcalase^® 2.4 L with different degrees of hydrolysis (DH) were investigated. With a DH of 65.83%, the hydrolysate prepared with papain exhibited the maximum of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activity (71.14%) with a reducing power of 0.310. At a concentration of 1 mg mL^?1, the papain‐MPH exhibited a Trolox equivalent antioxidant capacity (TEAC) of 70.50 ± 1.22 μmol g^?1 protein. With a DH of 83.6%, the Alcalase‐MPH had the highest metal‐chelating activity. Low molecular weight peptides showed higher antioxidant activities than high molecular weight peptides. Both papain‐MPH and Alcalase‐MPH contained high amounts of the essential amino acids (48.71% and 48.10%, respectively) with glutamic acid, aspartic acid and lysine as the dominant amino acids. These results suggest that the protein hydrolysates derived from patin may be used as an antioxidative ingredient in both functional food and nutraceutical applications.     

Preparation and characterisation of isoflavone aglycone‐rich calcium‐binding soy protein hydrolysates

Isoflavone aglycone‐rich calcium‐binding soy protein hydrolysates were prepared by subcritical water treatment and subsequent protease hydrolysis. Contaminated β‐glucosidase in the Protease M preparation could effectively convert glycosides into aglycones. Compared with Alcalase hydrolysates, Protease M hydrolysates exhibited higher molecular weight (>5000 Da) and more hydrophobic characteristics because of its weaker proteolytic activity. The antioxidant activity of Protease M hydrolysates was obviously improved. Initial increased DPPH and ABTS radical scavenging rate of Protease M hydrolysates may be ascribed to the conversion of isoflavones (<30 min) and a gradual release of antioxidant peptides. In the later hydrolysis, a gradual exposure of isoflavones involved in the interior of heat‐induced protein aggregates was mainly responsible for further improved antioxidant activities. Higher calcium‐binding capacity (up to 7.86%) with lower yield of peptide–calcium complex was observed for Protease M hydrolysates. These results could help researchers to develop a feasible protocol for producing nutrient‐enhanced soy protein hydrolysates.     

扫频超声处理时间对β-乳球蛋白酶解制备多肽抗氧化活性的影响

目的:研究不同扫频超声处理时间对β-乳球蛋白酶解制备多肽抗氧化活性的影响。方法:研究不同的超声预处理时间(10,20,30,60,90 min)对β-乳球蛋白表观结构的影响,以及超声波处理对β-乳球蛋白酶解产物的抗氧化活性、氨基酸组成、分子质量分布和疏水性的影响。结论:超声波处理可显著提高β-乳球蛋白酶解产物的DPPH自由基清除率、ABTS·清除能力和Fe2+络合能力。随着超声时间的延长,β-乳球蛋白酶解产物抗氧化活性呈先增加后降低的趋势。扫频超声波处理可以提高β-LG酶解产物的疏水性,并且显著增加多肽中的疏水性氨基酸的含量。扫频超声处理10~60 min有利于分子质量为200~2000 u多肽的生成,从而提高其酶解产物的抗氧化活性。粒径分布表明短时间的超声处理(<30 min)引起β-LG粒径减小,大分子蛋白的结构疏松,分子间的疏水性作用力增加;长时间(60~90 min)的超声处理则引起大分子蛋白聚集,疏水性作用力降低,蛋白颗粒粒径增大。     

Process optimisation and physicochemical characterisation of enzymatic hydrolysates of proteins from co‐products of Atlantic Salmon (Salmo salar) and Yellowtail Kingfish (Seriola lalandi)

The aim of this study was to develop an enzymatic hydrolysis process of protein co‐products for two major commercial fish species in Australia: Atlantic salmon (AS) and Yellowtail kingfish (YTK). The outcomes are to produce high protein recovery of fish protein hydrolysates within controlled molecular weight ranges that display enhanced physicochemical properties of oil binding and emulsification. Three enzymes (Flavourzyme, Neutrase and Alcalase) were applied to processing co‐products. Protein recovery and physicochemical properties were evaluated with increasing hydrolysis time from 30 min to 180 min and ratio of enzyme to substrate (E/S) from 0.5% to 3.0%. In order to achieve a product with optimum emulsifying capacity (50 ± 0.6 m² g^?1), an E/S ratio of 0.6–1.3% Flavourzyme was applied for 30–111 min with a protein recovery of 55%; in order to achieve a product with optimum oil‐binding capacity (8.3 ± 0.3 g oil g hydrolysates^?1), an E/S ratio of 2.3–3.0% Flavourzyme was applied for 25–64 min with a protein recovery of 70%. YTK protein hydrolysates were further membrane‐fractionated into five fractions (>100 kDa, 50–100 kDa, 30–50 kDa, 10–30 kDa and <10 kDa), and of these, the 10–30 kDa exhibited the best properties of oil binding (19 ± 0.3 g oil g hydrolysates^?1) and emulsification (57 ± 0.7 m² g^?1). These results demonstrate the importance of enzymatic hydrolysis of seafood co‐products into high‐value ingredients for food products and processing.     

不同蛋白酶对小麦蛋白酶解物抗氧化活性的影响

小麦蛋白是小麦淀粉加工的副产物,酶解是提高小麦蛋白溶解性和功能性的有效方式,而酶解用酶种类可能对酶解产物的功能性如抗氧化活性有一定影响。采用碱性蛋白酶、中性蛋白酶、胃蛋白酶、风味蛋白酶、胰蛋白酶、木瓜蛋白酶6种常用的蛋白酶分别对小麦蛋白进行酶解,并对酶解4 h后酶解物的多肽得率、分子质量分布、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、超氧阴离子自由基(O_2~-·)清除率、羟自由基(·OH)清除率等反映水解程度和抗氧化能力的主要指标进行评价。结果表明,风味蛋白酶酶解物中多肽得率最高,达91.44%,且分子质量小于3 000 D的多肽含量达76.9%;酶解物质量浓度为3 mg/m L时,木瓜蛋白酶酶解物对DPPH自由基清除作用最好,清除率为65.12%(P0.01),其次是风味蛋白酶(58.43%)和碱性蛋白酶(55.29%);碱性蛋白酶酶解物对O_2~-·清除率效果最好,清除率为58.68%(P0.01),其次是风味蛋白酶(49.25%);碱性蛋白酶和木瓜蛋白酶酶解物对·OH清除效果最佳,清除率分别为59.23%和58.16%。结果说明,蛋白酶种类对小麦蛋白酶解物抗氧化活性影响显著,风味蛋白酶对提高蛋白水解程度和生成小分子质量多肽的作用明显,而碱性蛋白酶、木瓜蛋白酶和风味蛋白酶对提高酶解产物抗氧化活性效果较好。