超声波辅助不同反胶束体系前萃7S和11S球蛋白的研究

主要研究了利用3种反胶束体系萃取7S、11S球蛋白,考查了缓冲溶液pH、WO、萃取温度、萃取时间等4因素对蛋白前萃率的影响规律,通过对3种反胶束体系提取7S、11S球蛋白的比较,筛选出最适于7S、11S蛋白的提取方法。在相同的条件下,AOT、CAB反胶束体系对大豆7S球蛋白的提取率一般高于对大豆11S球蛋白的提取率;而SDS反胶束体系对大豆7S球蛋白的提取率一般低于对11S球蛋白的提取率。为今后研究不同分子量大小的蛋白与反胶束"水池"微观结构相互关系的规律奠定基础。     

Optimization of extraction and isolation for 11S and 7S globulins of soybean seed storage protein

A new method was developed for extraction and isolation of 7S and 11S fractions from soybean seed, based on methods of Nagano et al., Thanh and Shibasaki [Nagano, T., Hirotsuka, M., & Mori, H. (1992). Dynamic viscoelastic study on the gelation of 7S globulin from soybeans. Journal of Agricultural and food chemistry 40, 941–944 and Thanh, V. H., & Shibasaki, K. (1976). Major proteins of soybean seeds. A straightforward fraction and their characterization. Journal of Agricultural and Food Chemistry 24, 1117–1121]. Optimization of the extraction and isolation of 11S and 7S globulins from soybean seed was investigated under various conditions by the Kjeldahl method and SDS-PAGE. The optimal conditions were as follows: 0.03–0.06 M Tris–HCl buffer (pH 8.5) containing 0.01 M sodium bisulfite as extract solution, extraction twice at 45 °C for 1 h, and with a 1:15 ratio (w/v) of flour:Tris–HCl. The 11S fraction was precipitated at pH 6.4, and the supernatant, after centrifugation, was adjusted to pH 5.5 to remove the insoluble intermediate fraction by further centrifugation. The supernatant obtained was then adjusted to pH 4.8 to afford the 7S fraction as a precipitate by centrifugation. With the improvements, the protein contents and purities of the isolated 11S and 7S fractions were significantly increased. The contents of all subunits of the isolated 11S and 7S fraction were markedly higher than those by Thanh and Shibasaki method, while the contents of α, β and B₃ were also significantly higher than those by Nagano et al. method.     

转谷氨酰胺酶对大豆11S蛋白疏水性的影响

利用转谷氨酰胺酶(TGase)对大豆11S球蛋白改性并对其疏水性进行研究.通过单因素考察和正交实验分析,得出最佳改性条件的组合为加酶量是30U/g,pH是7.5,反应温度是45℃,测得的最大11S蛋白表面疏水性指数(S0)为3076.6.     

大豆11S和7S蛋白质凝胶特性的研究综述

按照大豆蛋白质的构成,可以把11S和7S蛋白质凝胶特性的研究相对划分为3种类型:①蛋白质组分类型,研究11S和7S蛋白质热致凝胶的形成条件和部分特性;②分离蛋白类型,研究以11S和7S蛋白质为主要成分的大豆分离蛋白(SPI)凝胶特性;③蛋白质亚基类型,研究11S和7S蛋白质亚基的结构与凝胶形成机理的关系。对3种类型的研究具有相对的先后顺序,即在蛋白质组分类型基础上进行SPI类型的研究,在组分和SPI类型基础上进行亚基类型的初步研究,今后将对蛋白质亚基类型做深入研究。     

The characterization of soybean varieties by fluorescence spectroscopy

Fluorescence spectroscopy was used to differentiate between β‐conglycinin (βC) and glycinin (G) fractions that were isolated from four food grade soybean varieties (Glycine max var. K1430, Hutcheson, K93‐90‐29, and KS4997) grown in the same location. The protein fractions were discriminated by using spectroscopic tryptophan fluorescence emission and synchronous scanning techniques that took advantage of the sensitivity of the chromophore to changes in the protein environment. The relative intensities of the βC and glycinin fluorescence ranged from 1.00 to 1.30 and 1.00 to 1.31 respectively. The intensities of the βC and glycinin synchronous fluorescence ranged from 1.00 to 1.45 and 1.00 to 1.30 respectively. The spectroscopic method proved to be an effective technique to differentiate between different soybean varieties.     

7S和11S大豆球蛋白的分离研究

本研究选择低温脱脂大豆粕为原料,提出并采用碱提酸沉膜分离法来分离7S和11S大豆球蛋白,通过SDS-PAGE电泳鉴定分离纯度,并与传统的几种方法比较分离效果.结果表明,碱提酸沉膜分离法的分离效果明显优于传统的方法,所得的7S和11S大豆球蛋白的纯度可以分别达到75.5%和84.7%.     

大豆7S与11S球蛋白分离方法的研究

文章就提取分离低温脱脂大豆粕中大豆7S和11S球蛋白的方法进行了研究.利用SDS-PAGE凝胶电泳来评定不同pH值对分离大豆7S球蛋白和大豆11S球蛋白的纯度的影响.实验结果表明,浸提大豆蛋白的最佳工艺参数为磷酸盐缓冲液浓度为0.02 mol/L、料液比1∶16、浸泡温度45 ℃、pH值为8.5,可得到最高浸提率为89.55%.分离大豆11S球蛋白的最适pH值为6.2,纯度达75.76%;分离大豆7S球蛋白的最适pH值为4.7,纯度达72.99%.     

Comparison of acid-induced conformation changes between 7S and 11S globulin in soybean seeds

The acid-induced conformation changes between 7 and 11 S globulin, the major storage proteins in soybean seeds, were compared by ultraviolet difference spectra, ultracentrifugation and optical rotatory dispersion. Maximum denaturation occurred at approximately pH 2 in both and dissociation of the proteins into subunits and unfolding of the polypeptide chains were observed simultaneously. However, both proteins showed apparent differences in their readiness to undergo acid-induced denaturation. The differences were particularly remarkable in the presence of 0.1 ionic strength sodium chloride.     

大豆籽粒贮藏蛋白11S和7S组分提取分离方法的优化

为确定提取分离大豆贮藏蛋白11S和7S两种主要成分的最适方法,采用凯氏定氮和SDS-PAGE分析,从浸提液种类、提取液pH、浸提次数和温度、料液比、Tris-HCl浓度和还原剂种类等影响提取分离效果的因素着手,对Nagano法进一步优化。结果表明,浸提液采用pH 8.5、含0.01 mol/L亚硫酸氢钠的0.03~0.06 mol/L Tris-HCl缓冲液系统,提取温度45℃,料液比1∶15,重复浸提两次;分离过程中,在pH 6.4沉淀离心分离出11S组分、调pH 5.5沉淀离心分离出中间产物后,再调pH至4.8沉淀离心分离出7S组分。优化后的方法与Nagano法相比,可显著提高11S和7S组分的得率、蛋白含量和纯度。     

模拟酶解大豆7S、11S蛋白及其抗氧化活性的研究

以"活性肽搜寻与蛋白模拟水解系统"为工具,选择碱性蛋白酶和中性蛋白酶对大豆7S、11S蛋白进行模拟水解,得到不同水平的抗氧化肽肽段,以重均分子量为手段,评价理论模拟与实验水解的相关性;以还原力、清除二苯代苦味酰基苯肼(DPPH·)自由基能力比较以上蛋白酶水解物的抗氧化活性.结果表明:模拟与实验水解得到的分子量分布在比例以及重均分子量方面有显著相关性(P<0.01);四种酶解产物均具有一定的抗氧化活性,其中,以7S蛋白的碱性蛋白酶产物表现出最高的还原力和DPPH·清除能力(P<0.05).     

添加不同配比7S/11S大豆球蛋白对鸡肉丸品质的影响

从大豆蛋白中分离出7S、11S大豆球蛋白,根据7S与11S球蛋白不同的蛋白质功能性质,通过不同的比例配比,添加至鸡肉丸中,考察7S/11S(质量比)大豆球蛋白不同配比对鸡肉丸蒸煮损失、颜色、硬度、弹性、自旋-自旋弛豫时间(T_2)时间变化以及感官特征的影响。结果表明:随着7S/11S比值的增大,鸡肉丸的蒸煮损失显著降低(P0.05),亮度值显著增加(P0.05)、硬度和弹性以及结合水的能力也显著增强(P0.05)。当7S/11S比值为4∶1时,蒸煮损失降低至最低2.13%(P0.05),此时肉丸的亮度值达到最大值51.85,肉丸的硬度、弹性、咀嚼性、胶黏性和回复性显著增强(P0.05),并具有良好的感官评分。     

大豆乳清蛋白的热稳定性分析及其与球蛋白的相互作用研究

研究了大豆乳清蛋白在豆奶体系中的热稳定性,并进一步研究生豆奶在加热过程中大豆乳清蛋白与大豆球蛋白之间的相互作用。大豆乳清蛋白溶于生豆奶超滤液中,将加热前后的该溶液分别经SephacrylS-300凝胶过滤,发现大豆乳清蛋白加热后会发生热凝聚现象,形成较大的蛋白凝聚物。通过比较大豆乳清蛋白溶液和无乳清蛋白豆奶溶液对pH变化的敏感性,发现大豆乳清蛋白和大豆球蛋白在加热过程中会发生相互作用。     

大豆7S和11S球蛋白的结构和功能性质

主要介绍大豆７Ｓ和１１Ｓ球蛋白的结构和功能性质，大豆蛋白质各个成分的分子量有所不同，按超速离心分离系数可分为２Ｓ，７Ｓ１１Ｓ和１５Ｓ４个组份。７Ｓ组份占总蛋白质的３０．９％，它是由４种不同大豆蛋白民组成，１１Ｓ组份占总大豆蛋白质的４１％，而且都是单一的１１Ｓ球蛋白，１１Ｓ球蛋白的等电点为ｐＨ４．６４。     

大豆种子贮藏蛋白11S与7S组份的研究

大豆种子球蛋白组份的组成与蛋白品质密切相关。本实验利用SDS—PAGE梯度电泳分离11S球蛋白和7S伴球蛋白各亚基，通过软件Gel—pro analysis3．0计算了1757份大豆种质中11S和7S的相对含量(以蛋白亚基吸光值计算)以及11S／7S比值，结果表明，1757份大豆种子球蛋白11S／7S比值的变异幅度在0．72～2．99内，平均值为1．885；不同品种间亚基组份存在亚基含量和亚基缺失的变异，揭示了我国大豆遗传资源的多样性。大豆品种11S／7S比值在不同大豆生态区存在显著性差异，说明大豆11S／7S比值的高低具有一定的生态适应性；地方品种与育成品种的比较表明，同一生态区或同一省份地方品种11S／7S平均值显著高于育成品种：大豆种子粗蛋白含量的高低和11S／7S比值相关性不大，但是以大豆种子粗蛋白含量在40％～49％范围内．11S／7S比值在不同生态区之间的变异最为显著。     

Comparison of SDS gel capillary electrophoresis with microfluidic lab-on-a-chip technology to quantify relative amounts of 7S and 11S proteins from 20 soybean cultivars

SDS gel capillary electrophoresis (Beckman–Coulter ProteomeLab) and the lab-on-a-chip technology (Agilent 2100 Bioanalyzer) were used to quantify the relative amount of 7S and 11S fractions in twenty different soybean cultivars. The better repeatability of the migration times and peak areas was achieved for the Bioanalyzer. Both lab-on-a-chip instrument and a traditional capillary gel electrophoresis were shown to be adequate for analysis of soy-based products. Integrating the area of peaks within a certain range of molecular weights was used to calculate the relative content of each protein subunit. Poor agreement in the classification in the protein subunit groups between the two instruments was observed. Therefore, the approach of visual identification taking into account both the variability in the position of the peaks and the detection of different number of peaks between the profiles was applied. This resulted in statistically significant correlation being observed between 11S/7S ratios determined by Bioanalyzer and ProteomeLab ( R  = 0.82). The reported differences in 11S and 7S content between the studies are likely to be affected by the differences in the techniques used to analyse soy protein subunits. A brief presentation of the chemometric analysis of electrophoretic profiles as a common method for transforming electrophoretograms to multivariate data sets is shown.     

不同形态大豆磷脂产品中溶血磷脂酰胆碱含量研究

采用HPLC–ELSD法测定不同形态大豆磷脂产品中溶血磷脂酰胆碱(LPC)的含量,并通过对原料、工艺、储存期等因素的研究来确定溶血磷脂酰胆碱含量的变化规律。浓缩磷脂产品中LPC含量约为0.80%,大豆粉末磷脂中LPC含量为1.35%,大豆磷脂一次醇溶产品中LPC含量为2.87%,大豆磷脂二次醇溶产品中LPC含量为12.88%。在–20℃、避光储存条件下,各样品一年储存期内LPC含量的变化不大。     

大豆浓缩磷脂设备与工艺探讨

通过研究在工业条件下,如何利用水化豆油的油脚加工浓缩大豆磷脂,详细介绍了大豆磷脂的生产工艺过程,并对生产过程中的工艺条件控制进行了逐一的分析论述,同时对关键生产设备和操作安全注意事项进行了重点描述。     

流化床卵磷脂喷涂技术在豆奶粉生产中的应用

在充分调查国内豆奶粉厂现状的基础上,借鉴从国外引起设备的奶粉厂设计和使用经验,结合我国目前豆奶粉喷粉工段的实际情况,并熔入乳品界专家的设计经验,将流化床喷涂卵磷脂工艺应用到豆奶粉生产中,以提高豆奶粉的产量和质量。实践证明,设备的改造是成功的,尤其是在提高豆奶粉的质量方面。     

Changes in the protein complex of wheat dough affected by soybean 11 S globulin: Part 2—The interactions of soybean 11 S globulin with gluten proteins

The interactions between soy 11 S globulin and protein fractions of wheaten doughs were examined using a multistep extraction method followed by molecular sieving and characterisation of the fractions obtained. The soy 11 S globulin preparation was coupled with fluoresceine isothiocyanate to permit tracing of this protein in the complexes formed. In model experiments the average molecular weights of globulin/prolamine complexes were determined, the dispersion of light on the protein molecules being measured. The formation of high molecular weight complexes of soy 11 S globulin and prolamine was found. A shift between albumin/globulin and gluten fractions was also observed, which resulted in an increase in the contents of low molecular weight fractions dispersible in pyrophosphate buffer and acetic acid.Most of the investigations concerning the enrichment of bread with soybean proteins deal with technological problems. The documentation of the chemically induced changes in the dough-protein complex is rather limited and a number of questions are still awaiting answers. The data reported by Jakubczyk et al. (1973), Matthews (1972), Pollock & Geeds (1960a, b) do not explain the character of the interactions between soy proteins and gluten systems and give only inadequate information on the changes of molecular structure or aggregation/disaggregation phenomena occurring in the proteins of enriched dough. The results presented in our previous study (Lampart-Szczapa & Jankiewicz, 1982, encouraged us to continue the experiments to explain the rôle played by soybean 11 S globulin treated as a model soy protein in modifying the gluten matrix of wheat dough. In this paper the effects of soybean 11 S globulin on the fractional distribution of the dough-protein complex and average molecular weights of the fractions are presented.