Characterization of physicochemical and immunogenic properties of allergenic proteins altered by food processing:a review

Food allergens are mainly naturally-occurring proteins with immunoglobulin E(IgE)-binding epitopes.Understanding the structural and immunogenic characteristics of allergenic proteins is essential in assessing whether and how food processing techniques reduce allergenicity.We here discuss the impacts of food processing technologies on the modification of physicochemical,structural,and immunogenic properties of allergenic proteins.Detection techniques for characterizing changes in these properties of food allergens are summarized.Food processing helps to reduce allergenicity by aggregating or denaturing proteins,which masks,modifies,or destroys antigenic epitopes,whereas,it cannot eliminate allergenicity completely,and sometimes even improves allergenicity by exposing new epitopes.Moreover,most food processing techniques have been tested on purified food allergens rather than food products due to potential interference of other food components.We provide guidance for further development of processing operations that can decrease the allergenicity of allergenic food proteins without negatively impacting the nutritional profile.

GmSTF accumulation mediated by DELLA protein GmRGAs contributes to coordinating light and gibberellin signaling to reduce plant height in soybean

Plant height influences plant architecture,lodging resistance,and yield performance.It is modulated by gibberellic acid(GA)metabolism and signaling.DELLA proteins,acting as central repressors of GA signaling,integrate various environmental and hormonal signals to regulate plant growth and development in Arabidopsis.We examined the role of two DELLA proteins,GmRGAa and GmRGAb,in soybean plant height control.Knockout of these proteins led to longer internodes and increased plant height,primarily by increasing cell elongation.GmRGAs functioned under different light conditions,including red,blue,and far-red light,to repress plant height.Interaction studies revealed that GmRGAs interacted with the blue light receptor GmCRY1b.Consistent with this,GmCRY1b partially regulated plant height via GmRGAs.Additionally,DELLA proteins were found to stabilize the protein GmSTF1/2,a key positive regulator of photomorphogenesis.This stabilization led to increased transcription of GmGA2ox-7b and subsequent reduction in plant height.This study enhances our understanding of DELLA-mediated plant height control,offering Gmrgaab mutants for soybean structure and yield optimization.

Emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure

Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.

Studies on BN rats model to determine the potential allergenicity of proteins from genetically modified foods

AIM： To develop a Brown Norway （BN） rat model to determine the potential allergenicity of novel proteins in genetically modified food. METHODS： The allergenicity of different proteins were compared, including ovalbumin （OVA）, a potent respiratory and food allergen, bovine serum albumin （BSA）, a protein that is considered to have a lesser allergenic potential, and potato acid phosphatase （PAP）, a non-allergenic protein when administered to BN rats via different routes of exposure （intraperitoneally or by gavage）. IgG and IgE antibody responses were determined by ELISA and PEA, respectively. An immunoassay kit was used to determine the plasma histamine level. In addition, possible systemic effect of allergens was investigated by monitoring blood pressure. RESULTS： OVA provoked very vigorous protein-specific IgG and IgE responses, low grade protein-specific IgG and IgE responses were elicited by BSA, while by neither route did PAP elicit anything. In either routes of exposure, plasma histamine level in BN rats sensitized with OVA was higher than that of BSA or PAP. In addition, an oral challenge with BSA and PAP did not induce any effect on blood pressure, while a temporary drop in systolic blood pressure in few animals of each routes of exposure was found by an oral challenge with OVA. CONCLUSION： BN rat model might be a useful and predictive animal model to study the potential allergenicity of novel food proteins.

Study on screening potential allergenic proteins from infant milk powders based on human mast cell membrane chromatography and histamine release assays

Cow's milk allergy is mainly observed in infants and young children. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems. Conventional diagnosis is based on positive allergy studies and evaluation of parameters including IgE and IgG1 levels, acute allergic skin response and anaphylactic shock reactions. We developed a cell membrane chromatographic(CMC)method based on human mast cells(HMC-1) for screening potential allergens in infant formula milk powders(IFMP). HMC-1 cell membranes were extracted and mixed with silica to prepare cell membrane chromatography columns(10 mm ? 2 mm i.d., 5 mm). Under the conditions of 0.2 mL/min flow rate and214 nm detection wavelength, human breast milk showed no retention. However, IFMP showed clear retention. The retained fractions were collected and analyzed through matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Four major milk proteins, i.e., α-casein, β-casein, α-lactalbumin, and β-lactoglobulin A, were identified. Furthermore, these proteins and β-lactoglobulin B showed clear retention on HMC-1/CMC columns. To test the degranulation effects of the five proteins, histamine and β-hexosaminidase release assays were carried out. All five proteins induced HMC-1 cells to release histamine and β-hexosaminidase. Also, we established a reversed phase liquid chromatographic(RPLC) method for the determination of the five proteins in IFMP and the results showed that 90% proteins in IFMP were α-casein and β-casein. We concluded that cow's milk proteins may be potential allergens and caseins cause more β-casein allergic risk than other proteins. This conclusion was consistent with other studies.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

An innovative method used for the identification of N-glycans on soybean allergenβ-conglycinins

β-Conglycinin is one of the major allergens existed in soybean.N-Glycans attached to theβ-conglycinin influenced the immunoreactivity and antigen presenting efficiency ofβ-conglycinin.In this study,we described a new method used to release and collect the N-glycans fromβ-conglycinin,and the N-glycans existed in linear epitopes ofβ-conglycinin were identified.Glycopeptides hydrolyzed fromβ-conglycinin were purified by cotton hydrophilic chromatography.Trifluoromethylsulfonic acid was then used to release glycans from glycopeptides,and new glycopeptides containing one single N-acety1-D-glucosamine(G1 cNAc)moiety were then utilized for mass spectrometry.Five glycosylation sites(Asn-199,Asn-455,Asn-215,Asn-489 and Asn-326)and 22 kinds of glycopeptides were identified.It is noteworthy that the peptide VVN^(#)ATSNL(where^(#)represents for the glycosylation site)was analyzed to be both glycopeptide and linear epitope.Our results provided a new method for the N-glycoform analysis of food allergens,and laid a foundation for understanding the relationship between glyco sylation and food allergy.

Structure and allergenicity of a-lactalbumin:effects of ultrasonic prior to glycation and subsequent phosphorylation

Bovineα-lactalbumin(BLA)induced severe cow's milk allergy.In this study,a novel strategy combining ultrasonication,performed before glycation,and phosphorylation was proposed to reduce BLA allergenicity.Result showed that IgE-and IgG-binding capacities and the release rates of histamine and interleukin-6 from RBL-2 H3 were reduced.Moreover,intrinsic fluorescence intensity and surface hydrophobicity were decreased,whereas glycated sites(R10,N44,K79,K108,N102 and K114)and phosphorylated sites(Y36 and S112)of BLA were increased.Minimum allergenicity was detected during BLA treatment after ultrasonic prior to glycation and subsequent phosphorylation because of considerable increase in glycated and phosphorylated sites.Therefore,the decrease in allergenicity of BLA,the effect correlated well with the shielding effect of glycated sites combined with phosphorylated sites and the conformational changes.This study provides important theoretical foundations for improving and using the ultrasonic technology combined with protein modification in allergenic protein processing.

Proteomic Studies of Petal-specific Proteins in Soybean [Glycine Max(L.)Merr.] Florets

A survey of petal-specific proteomes of soybean(Glycine max(L.) Merr[Non-italic].) was conducted comparing protein expression profiles in different petals. Two-dimensional polyacrylamide gel electrophoresis reference maps of protein extracts from standard petals(SP), lateral wings(LW), keel petals(KP), and reproductive organs(RO)(a mixture of stamen and carpel) were obtained. Protein expression in the three petal types was compared using Image Master TM 2 D platinum 6.0 software. This indicated that the proportion of homologous proteins between SP and LW was 59.27%, between SP and KP was 61.48%, and between LW and KP was 60.05%. Within a mass range of 6.5-200.0 ku and pH 4.0-7.0, approximately 590, 646, 544, and 700 protein spots were detected in SP, LW, KP, and RO, respectively. A total of 82 differentially expressed proteins were detected. Sixty-four of these detected spots were differentially expressed and showed more than 2-fold changes in abundance; of these 64 proteins, 26 showed increased expression and 38 showed decreased expression. Among these spots, single organ-specific proteins were also identified.They were ID 49(60.9 ku), ID 45(50.0 ku), and ID 46(40.5 ku) in RO, ID 98(42.0 ku) in SP, and ID 05(29.0 ku) in KP. A total of 14 protein spots from 82 differentially expressed proteins were identified with LC-MS/MS. Further protein identification was conducted using the SwissProt and NCBInr databases. The identified proteins and their putative functions were discussed further. This was the first study reporting the comparison of petal protein profiles of soybean florets using proteomics tools.

Genome-wide analysis of soybean DnaJA-family genes and functional characterization of GmDnaJA6 responses to saline and alkaline stress

Plant Dna JA proteins act as molecular chaperones in response to environmental stressors.The purpose of this study was to characterize the function and regulatory mechanisms of Dna JA genes in soybean.Gene expression profiles in various soybean tissues at various stages of development indicated that Gm Dna JAs function in the coordination of stress and plant hormone responses.Gm Dna JA6 was identified as a candidate regulator of saline and alkaline stress resistance and Gm Dna JA6 overexpression lines showed increased soybean saline and alkaline tolerance.Dna J interacted with Hsp70,and Gm Hsp70 increased the saline and alkaline tolerance of plants with chimeric soybean hairy roots.

Novel Gluten-Free Amaranth and Oat Flour Cookies Fortified with Soybean Hulls

Soybean hulls, an abundant byproduct of soybean processing, contain rich phytochemicals, fibers, proteins, and minerals. Currently soybean hulls are primarily used as animal feeds. For value-added soybean hull utilization, 25% soybean hulls were substituted for amaranth or whole oat flour (WOF) in novel gluten-free cookies. Composition, nutritional values, water-holding capacities, correlation between properties, and pasting and rheological properties of soybean hulls, amaranth, and WOF were appraised in comparison to wheat flour. Water loss, cookie texture, and geometrical properties of the cookies were examined. The results disclosed that soybean hulls, amaranth and WOF contain higher protein content, minerals, fiber, special amino acids, and critical vitamins (C and K) than wheat flour. Considerably higher total amino acid content was found in soybean hulls (18.33%) than wheat flour (12.77%). Water-holding capacities increased by replacing amaranth and WOF with soybean hulls. Soybean hulls exhibited higher rheological elastic properties than amaranth, WOF and wheat flours. The soybean hulls utilized in amaranth or WOF cookies greatly improved their nutritional value, the water retention and moisture content along with acceptable physical properties when compared to wheat flour cookies. This study explored the feasibility and potential of utilizing soybean hulls with amaranth and WOF in gluten-free bakery products and other food applications.

Effects of Rare Earth Lanthanum and Cerium on Key Enzyme Activi-ties of Soybean Nitrogen Metabolism

In this study,the typical northeast soybean varieties Dongnong 42(high protein),Dongnong 47(high fat)and Dongnong 52(mixed-use)were used as experimental materials and planted in pots.Foliar spraying 100,150 and 200 mg•L^(-1)LaCl_(3)solution,30,60 and 90 mg•L^(-1)CeCl_(3)solution and 40,60 and 70 mg•L^(-1)LaCl_(3)+CeCl_(3)mixed solution.To study the effects of different types and concentrations of rare earth on nitrate reductase activity,glutamine synthetase activity of soybean leaves and protein content of soybean grains.The results showed that spraying appropriate concentration of rare earth solution on the leaves could increase the activities of nitrate reductase and glutamine synthase in soybean functional leaves and the protein content of soybean grains.The protein content of the three types of soybean grains was significantly positively correlated with the activity of nitrate reductase and glutamine synthetase in the leaves.

利用乳酸乳球菌发酵大豆蛋白产低聚肽的研究

筛选可以发酵分解大豆蛋白的食源性微生物,对分解产生的多肽进行分子量分析,通过分离纯化获得低聚肽并研究其抗氧化活性。结果表明:从自制泡菜中分离到一株食源性乳酸菌PZ1,经形态和16S rDNA鉴定为乳酸乳球菌;全基因组分析PZ1菌株具有多种肽酶和蛋白酶基因,具备分解蛋白的潜在能力;利用PZ1发酵大豆分离蛋白,采用凝胶渗透色谱分析发酵产生的多肽,分子量1000 Da以下占比达85%;通过超滤纯化获得300~1000 Da的低聚肽;研究大豆低聚肽的抗氧化活性,发现低聚肽对DPPH自由基、羟基自由基(·OH)和超氧阴离子自由基(O_(2)^(−)·)均有较好的清除作用,浓度为2 mg/mL时,清除率分别为79.31%、78.27%和84.62%。因此乳酸乳球菌PZ1能够高效降解大豆蛋白,可作为益生菌应用于大豆功能产品的开发。

黔豆系列品种贮藏蛋白亚基组成及其含量分析

为明确黔豆系列大豆品种(品系)中大豆球蛋白组分及其各亚基组分含量,以促进营养或加工专用大豆新品种的选育与应用,本研究利用聚丙烯酰胺凝胶电泳(SDS-PAGE)对41份大豆品种(品系)的7S和11S球蛋白亚基组成、相对百分含量和11S/7S比值进行分析。结果表明,各品种间大豆蛋白及其亚基组分相对百分含量存在较大差异;41份供试品种(品系)的7S、11S球蛋白平均相对百分含量分别为26.93%、54.92%,变幅分别为15.58%~43.89%、37.10%~66.48%,变异系数分别为29.36%、13.57%;11S/7S值为0.85~4.05,平均值为2.28,变异系数为38.71%;7S蛋白的变异系数高于11S蛋白,7S蛋白β亚基的变异系数最大,11S蛋白B亚基的变异系数最大,表现出更丰富的遗传多样性;筛选出11S/7S值高于3的品种11份,其中高于4的品种2份;7S与11S球蛋白组分间存在极显著负相关;系统聚类将41份供试品种(品系)聚类为三类,第Ⅰ类群11S蛋白含量和11S/7S平均值最高,第Ⅱ类群A 4、A 1A 2亚基平均含量最高,第Ⅲ类群7S蛋白和A 3亚基的平均含量最高。

不同贮藏温度对采后菜用大豆3种营养物质含量的影响

【目的】探明不同贮藏温度条件下菜用大豆中蔗糖、蛋白质和维生素C(V_(C))3种营养物质含量的变化规律,为菜用大豆贮藏保鲜和加工提供理论依据。【方法】在4℃(低温)和-20℃(速冻)贮藏条件下,分别于0 d、5 d、10 d测定川鲜豆1号、川豆155和川鲜豆2号3个菜用大豆品种的蔗糖、蛋白质含量,在-20℃(速冻)和-70℃(超低温)贮藏条件下,分别于0 d、15 d、30 d、45 d、60 d、90 d测定3个菜用大豆品种的V_(C)含量。【结果】4℃和-20℃贮藏,3个菜用大豆品种蔗糖含量随时间延长呈下降趋势,2种贮藏温度下蔗糖含量差异显著。4℃贮藏,蔗糖含量前5 d下降缓慢,5~10 d急剧下降,损失率为50.8%~60.9%;-20℃贮藏,蔗糖含量下降较缓慢,5~10 d损失率低于10%,-20℃贮藏可显著抑制采后大豆蔗糖含量的下降。蛋白质含量在4℃贮藏10 d内呈上升趋势,-20℃贮藏10 d内小幅下降,4℃贮藏的蛋白质含量均显著高于-20℃贮藏,-20℃贮藏抑制采后菜用大豆蛋白质的合成。V_(C)含量在-20℃和-70℃贮藏90 d内随时间延长而逐渐下降,下降幅度较缓,均小于10%。【结论】-20℃贮藏条件下菜用大豆蔗糖、蛋白质和V_(C)含量变化较小,宜作为菜用大豆采后短期保鲜贮藏方式。

限制性酶解结合糖基化改性对大豆分离蛋白乳化性质的影响

目的:开发基于大豆分离蛋白(soybean protein isolate,SPI)的新型乳化剂。方法:采用限制性酶解结合糖基化处理对SPI进行结构修饰,研究协同改性对SPI乳化特性的影响。结果:SPI水解物(soybean protein isolate hydrolysate,SPIH)中的相对分子质量较大组分(F30)的乳化性最佳,且糖基化反应4 h的F30-葡聚糖轭合物乳化稳定性相对最好。相较于SPI,SPIH与F30,F30-葡聚糖轭合物稳定的乳液表现出最低的初始平均粒径,并且具有最佳的贮藏稳定性。当pH接近SPI等电点或体系处于高盐浓度时,所有乳液均出现不稳定聚集现象。与SPI相比,SPIH和F30稳定乳液的聚集程度更高,而F30-葡聚糖轭合物由于共价结合的葡聚糖提供了额外的空间位阻和亲水性,使得轭合物稳定的乳液能够耐受离子强度和温度的变化,在不利环境条件下表现出更高的抵抗力。结论:限制性酶解结合糖基化改性是开发SPI基乳化配料的潜在可靠途径。

发酵降低大豆组织蛋白豆腥味的复合菌株筛选

采用顶空固相微萃取-气相色谱-质谱联用技术并结合风味活度值和感官评价,比较了生香酵母、活性干酵母、植物乳杆菌和肉葡萄球菌对大豆组织蛋白(textured soybean protein,TSP)豆腥味的降低效果,筛选出可有效降低豆腥味的2种菌株,并研究其复配质量比和添加方式。结果表明,4种菌对大豆组织蛋白豆腥味均有一定的消减效果,其中活性干酵母的降腥效果最明显,其发酵TSP中豆腥味物质含量减少了70%;肉葡萄球菌的增香作用最大,其发酵TSP中良好风味物质的含量增加了865.41%。选择活性干酵母作为降腥菌、肉葡萄球菌作为增香菌,二者复配适宜的的质量比为10∶1,添加方式为先加肉葡萄球菌于20℃发酵12 h后加活性干酵母于该温度下发酵20 h。

羊乳清蛋白部分和深度水解工艺、水解物致敏性及肽谱分析

利用羊乳清蛋白制备低致敏性配料是目前乳品工业的研究热点。乳清蛋白是乳中主要的蛋白质之一,也是引起婴幼儿过敏反应的主要成分,将蛋白质水解为小分子肽是降低其致敏性的有效方法。以山羊乳清蛋白为原料,研究了部分水解乳清蛋白和深度水解乳清蛋白的水解工艺和水解物特性(水解度、分子质量分布和β-乳球蛋白抗原性),并利用液相色谱串联质谱法(L C-MS/MS)比较了部分水解和深度水解工艺中过敏表位酶切位点的差异。研究结果表明,中性蛋白酶和碱性蛋白酶对羊乳清蛋白水解效果较好,其中碱性蛋白酶的水解度最高,达21.26%。经电泳分析,单酶水解后的产物中仍存在大分子多肽链,深度水解工艺需要复合酶水解。在酶底比为4000 U/g时,使用碱性蛋白酶在pH值为10.0、温度为55℃条件下水解羊乳清蛋白1.0 h,部分水解产物的水解度为12.31%,分子质量在5 kDa以下的多肽占95.18%,β-乳球蛋白抗原性下降率为9.40%。中性蛋白酶和碱性蛋白酶的质量比为1∶1,酶底比为6000 U/g,在pH值为8.5、温度为50℃条件下,水解羊乳清蛋白3.0 h,深度水解产物的水解度为35.58%,分子质量低于3 kDa的多肽为97.26%,β-乳球蛋白抗原性下降率为40.97%。部分水解和深度水解均能破坏β-乳球蛋白的大部分过敏表位,但相较于部分水解,深度水解能更大程度地降低乳清蛋白的致敏性。研究旨在为低致敏性羊水解乳清蛋白的生产提供一定的理论参考。

微波条件下大豆蛋白-绿原酸复合物的理化及结构特性

为探究微波条件下绿原酸对大豆蛋白理化性质和结构特性的影响,采用微波处理大豆蛋白-绿原酸复合物,分析其溶解度、持水性、乳化性、持油性和起泡性的变化,进而对其晶体结构进行表征并观察颗粒形态。结果表明:添加绿原酸使大豆蛋白的溶解度、持油性、起泡性降低,分别为290.55μg/mL,269.70%,143.67%,而泡沫稳定性和乳化性升高,分别为21.67%和43.00%;在功率700 W下微波处理5 min,可使大豆蛋白-绿原酸复合物的溶解度、持油性、泡沫稳定性和乳化性升高,分别达到368.00μg/mL,402.51%,156.30%和52.67%,而持水性降低至432.88%。大豆蛋白-绿原酸复合物结构分析结果显示,衍射峰强度和结晶度下降,并出现新的衍射峰,粒径明显减小,表面粗糙,凹凸不平,结构向内部卷曲,且受微波作用影响明显。结论:微波处理可在一定程度上抵消因多酚加入而引起的蛋白质溶解性和持油性的降低,微波条件下加入绿原酸能有效改善大豆蛋白的起泡性和乳化性能。

不同酶解条件下大豆分离蛋白结构特性及起泡性研究

以大豆分离蛋白(SPI)为原料,采用碱性蛋白酶(Alcalase)进行酶解(0~180 min),通过凝胶电泳、傅里叶红外光谱(FT-IR)和内源荧光光谱等方法探究酶解产物的结构变化;通过表面张力、界面蛋白吸附量等指标说明酶解产物的界面行为,并分析结构变化和界面行为对泡沫性质的影响。经酶解后,蛋白中7S和11S典型条带消失并有新条带产生(约24 ku);与SPI相比,水解物中α-螺旋含量减少,β-转角和无规则卷曲含量增加;荧光波长发生红移。以上结果说明蛋白结构展开,进而促进蛋白功能性的改变。结果发现,酶解90 min时样品起泡性最好(起泡性指数143.20%),可能由于此时水解物平均粒径最低(208.10 nm),溶解度较高(90.44%),表面张力最低,有利于提升水解物在空气-水界面的吸附速率,但由于酶解作用产生较小的肽段失去了蛋白质网络结构的能力,因而对泡沫稳定性有负面的影响。此外,酶解作用大大提高了蛋白抗氧化性。通过酶解可以有效地改善SPI的起泡性,拓宽了酶解后的SPI作为一种有效的起泡剂在食品中的应用范围。