影响大豆分离蛋白乳化稳定性测定的几种因素研究

采用离心法对影响大豆分离蛋白乳化稳定性的测定结果的几种因素进行了研究。通过研究得出如下结论：对乳化稳定性影响最大的是油相体积分数，然后依次是蛋白质溶液浓度、pH、离子强度、离心速度。在测定的范围内，均质速度、均质时间、水浴加热时间、加热温度和离心时间对测定结果的影响都很小。     

辐照对大豆分离蛋白功能特性影响

采用大豆分离蛋白为原料,经辐照处理达到对大豆分离蛋白物理改性的目的。测定吸水、吸油特性和乳化特性的变化,并分析吸水、吸油特性和乳化特性之间的相关性。结果表明：经辐射处理后,大豆分离蛋白吸水性变化不明显;当辐射剂量为4kGy 时,大豆分离蛋白吸油性及乳化性分别为最低值和最高值,吸油性的降低及辐射剂量的增加分别对大豆分离蛋白乳化性及乳化稳定性的提高有促进效果。     

提高大豆分离蛋白乳化性及乳化稳定性的研究

为了拓宽大豆分离蛋白在食品中的应用，提高其乳化性及乳化稳定性。研究了大豆分离蛋白物理、化学和生物改性，并对改性前后大豆分离蛋白的乳化性及乳化稳定性进行了比较。同时也探讨了pH对大豆分离蛋白及其改性物形成乳状液的影响，并利用成膜蛋白质分子所受的相互作用解释了蛋白质的乳化稳定性受外界条件和内部因素所发生的变化。研究发现适度改性可以提高大豆分离蛋白乳化性及乳化稳定性；碱性有利于大豆分离蛋白及其改性物乳化性的提高；而且用吸光值比(K)可较好地表示乳化稳定性．     

聚磷酸钠对大豆分离蛋白的修饰研究

采用多聚磷酸钠对大豆分离蛋白进行磷酸化修饰,研究磷酸化反应的工艺条件及改性后大豆分离蛋白几种功能特性的变化。结果表明:当大豆分离蛋白4%、三聚磷酸钠9%、反应初始pH9、反应时间3h时,磷酸化程度最大;磷酸化后的大豆分离蛋白的溶解性、乳化性以及粘度都有不同程度的改善。     

玉米醇溶蛋白提取工艺及功能性质研究

阐述了玉米醇溶蛋白的提取工艺，并对玉米醇溶蛋白的吸水性、持水力、湿润性、吸油性、乳化性、乳化稳定性、凝胶性和粘度等功能特性进行了测定，并与大豆分离蛋白和酪蛋白的相关性质进行比较，结果表明：玉米醇溶蛋白的吸水性低于大豆分离蛋白，但高于酪蛋白；玉米醇溶蛋白具有较好湿润性、吸油性、凝胶性，较弱的持水力和乳化性，一定的乳化稳定性．粘度随时间增加而增大。     

蒸谷米糠蛋白乳化性的研究

研究在不同质量浓度、不同温度、不同pH值、不同离子强度、不同蔗糖质量浓度等条件下,蒸谷米糠蛋白的乳化性和乳化稳定性的变化规律,并和大豆分离蛋白做比较。结果发现:蒸谷米糠蛋白乳化性和乳化稳定性均高于大豆分离蛋白,并变化幅度较大;温度、pH值对蒸谷米糠蛋白乳化性和乳化稳定性影响也较大,pH值接近中性可以平衡乳化性和乳化稳定性相互制约。     

超声-琥珀酰化复合改性提高大豆分离蛋白乳化性的研究

为提高大豆分离蛋白的乳化性,采用超声和琥珀酰化两种方法对大豆分离蛋白进行复合改性。通过单因素实验研究底物浓度、超声功率、超声时间、琥珀酸酐添加量和酰化反应温度对大豆分离蛋白乳化性的影响。在单因素实验的基础上,运用响应面法优化出超声-琥珀酰化改性大豆分离蛋白的适宜条件:超声功率569.36W、超声时间9.79min、酰化温度49.72℃。该条件下制得的改性大豆分离蛋白的乳化活性和乳化稳定性与未改性的大豆分离蛋白相比较,分别提高了3.05倍和4.65倍。     

超声-琥珀酰化复合改性提高大豆分离蛋白乳化性的研究

为提高大豆分离蛋白的乳化性,采用超声和琥珀酰化两种方法对大豆分离蛋白进行复合改性。通过单因素实验研究底物浓度、超声功率、超声时间、琥珀酸酐添加量和酰化反应温度对大豆分离蛋白乳化性的影响。在单因素实验的基础上,运用响应面法优化出超声-琥珀酰化改性大豆分离蛋白的适宜条件:超声功率569.36W、超声时间9.79min、酰化温度49.72℃。该条件下制得的改性大豆分离蛋白的乳化活性和乳化稳定性与未改性的大豆分离蛋白相比较,分别提高了3.05倍和4.65倍。      

大豆分离蛋白种类及取代量对冰淇淋品质的影响

研究了不同来源的大豆分离蛋白Ⅰ、Ⅱ、Ⅲ、Ⅳ的起泡性、泡沫稳定性、乳化性及乳化稳定性,并以20%～50%的取代率替代全脂乳粉生产冰淇淋,通过测定冰淇淋浆料粘度、硬度、膨胀率等指标,研究大豆分离蛋白来源与取代度对冰淇淋品质的影响。结果表明,冰淇淋浆料粘度及硬度均随四种来源的大豆分离蛋白取代率的增加而显著提高;不同来源的大豆分离蛋白,其取代率对冰淇淋膨胀率影响不同,膨胀率随着大豆分离蛋白Ⅰ取代率的增加而提高,随着大豆分离蛋白Ⅳ取代率的提高而降低;大豆分离蛋白来源不同,其取代率对冰淇淋融化率影响趋势基本一致,随着取代率的增加,融化率略有升高然后快速下降;大豆分离蛋白冰淇淋感官评价综合指标随着取代率的增加先升高后降低。而且研究结果还表明,大豆分离蛋白冰淇淋的膨胀率与起泡性无相关性;皮尔逊相关性分析表明在一定粘度范围内,膨胀率与大豆分离蛋白乳化性呈正相关。      

物理改性对大豆分离蛋白功能性质的影响

采用加热、紫外辐射、超声波振荡、均质分散和微波辐射5种物理方法对大豆分离蛋白进行改性处理,观察蛋白分散性、分散稳定性、乳化性、乳化稳定性、起泡性、起泡稳定性、黏度的变化。对5种物理改性方法的作用效果进行了横向比较,结果表明微波辐射的改性效果最好。对5种物理改性的蛋白质电泳分析表明,物理改性基本上不改变大豆分离蛋白的结构。     

Improving Functional Properties of Soy Protein Hydrolysate by Conjugation with Curdlan

ABSTRACT:  Soy protein hydrolysate was conjugated with curdlan through the naturally occurring Maillard reaction to extend its application in food processing. The gel-forming and emulsifying properties of soy protein hydrolysates were significantly improved ( P < 0.05) by conjugation with curdlan. The soy protein hydrolysate–curdlan conjugate (SPHCC)–soy protein isolate (SPI) mixed gel had a much thicker network than the soy protein hydrolysate and SPI mixed gel judged from scanning electron microscopic images. The improvement of gelling properties of soy protein hydrolysate by curdlan-conjugate was attributed to both the decrease in the repulsive forces among soy protein hydrolysates and the increase in the solubility. The covalent binding of soy protein hydrolysates and curdlan also showed a profound effect on the antioxidative activity of the soy protein hydrolysates. The higher antioxidative activity of SPHCC was related to the peptide reductants produced from the Maillard reaction and the higher emulsifying property of SPHCC. The conjugates of soy protein hydrolysate and curdlan can be used as a functional food additive having excellent gel-forming, emulsifying properties and antioxidative activity.     

复合添加剂提高调理肉饼乳化性的工艺优化

为提高调理肉饼的乳化性（保水性和保油性）,以卡拉胶、大豆分离蛋白、黄原胶和复合磷酸盐为添加剂,分别以水分流失率和脂肪流失率为指标,考察4 种添加剂对调理肉饼乳化性能的影响,并通过正交试验优化4 种添加剂的最佳配比。结果表明：单一添加组分能够改善调理肉饼的保水保油性;与单一添加相比,复合添加进一步提高了调理肉饼的乳化能力,其中以0.6%卡拉胶、4%大豆分离蛋白、0.6%黄原胶和0.5%复合磷酸盐组合的乳化性能较强,水分流失率和脂肪流失率分别为15.26%和11.17%。上述研究结果表明,将复合添加剂应用于调理肉饼加工中能提高其保水保油性,增强乳化性能。     

大豆分离蛋白乳化性的研究

采用蛋白质乳化容量电导法,对不同浓度、ＰＨ和酶水解条件下大豆分离蛋白乳化容量和乳化稳定性进行测定,结果表明：大豆蛋白的乳化性在低密度时随浓度上升而增加,浓度达到６％以后趋于稳定;等电点时（ＰＨ４．５）,乳化性最差,偏离等电点后尤其在偏碱性条件下,乳化性明显增加,酶水解后,乳化性变化产大,水解度１７％时,乳化性最佳。     

Composition and Functional Properties of Soy Protein Isolates Prepared Using Alternative Defatting and Extraction Procedures

ABSTRACT: In this study, the effects of alcohol defatting using ethanol, methanol, and non-alcoholic aqueous extraction methods on the yield, purity, and functionality of soy protein isolates were investigated. Soy protein extraction conditions were also modified (heat and mild acidic treatment before protein alkaline extraction, heat isoelectric precipitation, and non-neutral resolubilization of proteins), and the effects on the isolate properties were evaluated. Results showed that ethanol and aqueous extraction were potential alternatives to hexane. The soy protein isolates (SPI) obtained from these samples had protein contents of more than 90% and 84%, respectively, with functional properties comparable to those of SPI prepared from hexane defatted meal. Major differences were a decrease in the emulsifying activity properties of the SPIs resulting from the alternative defatting techniques, with, however, improved emulsion stability and foaming properties for the aqueous extracted SPIs. A marked decrease in the fat-holding capacity of the SPI made from methanol defatted meal was also noted. Modifying the protein isolation procedure also greatly influenced the functional properties of soy protein isolates. The results of the present investigation demonstrate that soy processing conditions can be modified to obtain soy proteins ingredients with specific functional properties.     

高功能性大豆浓缩蛋白的性能及在肉制品中应用的研究

高功能性大豆浓缩蛋白（FSPC）的乳化活性及乳化稳定性与大豆分离蛋白相似，对固体脂肪的乳化能力超过分离蛋白，在乳化型碎肉制品中添加可使产品得率及质构超过添加分离蛋白的肉制品。作者认为FSPC的功能性质可能与蛋白分子形成可溶性聚集体有关。     

Interaction and Functionality of Mixed Myofibrillar and Enzyme-hydrolyzed Soy Proteins

ABSTRACT Native and briefly heated (85 °C for 3 min) soy protein isolates (SPI) were partially hydrolyzed (4% DH) by Alcalase® and Flavourzyme™ before incorporation into a pork myofibril isolate (MPI) system. The hydrolysis of soy protein enhanced its interaction with MPI, leading to a decreased thermal stability of both soy and muscle proteins. Alcalase SPI hydrolysates, when compared with nonhydrolyzed SPI, improved viscoelastic properties and hardness of MPI gels, while Flavourzyme SPI hydrolysates had an adverse effect. Hydrolyzed SPI augmented emulsifying properties of MPI; the specific efficacy depended upon the type of enzymes used, the SPI:MPI ratio, and whether SPI was heated before hydrolysis.     

功能性大豆浓缩蛋白的性能及应用研究

功能性大豆浓缩蛋白（ＦＳＰＣ）的乳化活性及乳化稳定性与大豆分离与蛋白相似，对固体脂肪的乳化能力超过分离蛋白，在乳化型碎肉制品中添加可使产品得率及质构超过添加分离蛋白的肉制品，作者认为ＦＳＰＣ的功能性质可能与蛋白分子形成可溶性聚集体有关。     

Effects of homogenization on the molecular flexibility and emulsifying properties of soy protein isolate

The sensitivity of soy protein isolate (SPI) to trypsin was characterized by its flexibility. The effects of different homogenization conditions on soy protein isolate flexibility and emulsifying properties were investigated. Set the homogenization pressure was 120 MPa (megapascal) and the homogenous number of times is 0–4 times, the flexibility increases with the increase of the homogenization times (0–3 times), the change trend of flexibility is not obvious (3–4 times). When the homogenization times was 0–3 times, the emulsifying activity increases, and the emulsifying activity was the strongest at 3 times, after homogenization 3 times, the change trend of emulsifying activity is not obvious, the trend of emulsification stability and emulsification activity were similar. The surface hydrophobicity increases with the increase of homogenization times, while the turbidity decreases. The other structural indicators such as Ultraviolet scanning and endogenous tryptophan fluorescence spectroscopy suggest that the structure of SPI becomes more stretch as the flexibility increases.     

高压均质对大豆分离蛋白功能性质的影响

为了了解高压均质技术对大豆分离蛋白（SPI）功能性质的影响,采用不同的均质压力、均质次数和料液比对大豆分离蛋白溶液进行了高压均质处理,并分析处理前后SPI功能性质的变化.结果表明：高压均质可在一定程度上提高SPI的溶解性、乳化活性及其稳定性和起泡性及泡沫稳定性.均质压力在0～70 MPa的范围内升高时,SPI的溶解性、乳化稳定性、起泡性和泡沫稳定性得到了相应的改善,而乳化活性在压力为40 MPa时达到最高;均质次数由1次向3次增加时,SPI的乳化稳定性、起泡性及泡沫稳定性得到了提高,而溶解性和乳化活性则降低;均质物料料液比在1∶16～1∶8 （g∶mL）的范围内逐步增大时,SPI的各项功能性质均有不同程度的提高,并在料液比为1∶8时达到了最高值.