Department of Food Science and Technology, University of Georgia, Athens, Georgia 30602, USA.
J Agric Food Chem. 2013 Jan 16;61(2):387-93. doi: 10.1021/jf3032606. Epub 2012 Dec 28.
Soybeans stored under adverse conditions decrease in protein recovery (content) in the soymilk and tofu yield. This study investigated how protein structural changes contributed to the decrease in tofu yield. Soymilks were produced from original soybeans (Proto and IA2032 cultivars) and adversely stored soybeans, respectively, and soymilk protein contents were adjusted to the same level before making into tofu. Tofu yield was compared with that made from soybeans without protein content adjustment. For understanding protein structural changes, soy proteins were extracted from Proto soybean by using different solvents, including distilled water, sodium dodecyl sulfate (SDS), and 2-mercaptoethanol. The proteins in the extracts were analyzed by using SDS-PAGE and gel filtration. Results showed that tofu yield was more significantly affected by protein structural characteristics than the protein content in soymilk. Different levels of aggregations among 7S and 11S proteins during adverse storage were responsible for decreasing protein recovery in the soymilk.
在不利条件下储存的大豆会降低豆浆和豆腐产量中的蛋白质回收率（含量）。本研究探讨了蛋白质结构变化如何导致豆腐产量下降。分别用原始大豆（Proto 和 IA2032 品种）和储存不当的大豆生产豆浆，并在制成豆腐之前将豆浆的蛋白质含量调整到相同水平。比较了不调整蛋白质含量制成的豆腐的产量。为了了解蛋白质结构的变化，用不同的溶剂（包括蒸馏水、十二烷基硫酸钠（SDS）和 2-巯基乙醇）从 Proto 大豆中提取大豆蛋白。用 SDS-PAGE 和凝胶过滤分析提取物中的蛋白质。结果表明，豆腐产量受蛋白质结构特性的影响比豆浆中的蛋白质含量更为显著。在不利储存过程中，7S 和 11S 蛋白之间的不同聚集程度是导致豆浆中蛋白质回收率降低的原因。
