pH值和离子强度对大豆蛋白凝胶热诱导形成及其流变学性质的影响，与变性及其蛋白质组成的关系。

Influence of pH and ionic strength on heat-induced formation and rheological properties of soy protein gels in relation to denaturation and their protein compositions.

作者信息

Renkema Jacoba M S, Gruppen Harry, van Vliet Ton

机构信息

Centre for Protein Technology TNO-WU and Laboratory of Food Physics, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.

出版信息

J Agric Food Chem. 2002 Oct 9;50(21):6064-71. doi: 10.1021/jf020061b.

DOI:10.1021/jf020061b

PMID:12358481

Abstract

The influence of pH and ionic strength on gel formation and gel properties of soy protein isolate (SPI) in relation to denaturation and protein aggregation/precipitation was studied. Denaturation proved to be a prerequisite for gel formation under all conditions of pH and ionic strength studied. Gels exhibited a low stiffness at pH >6 and a high stiffness at pH <6. This might be caused by variations in the association/dissociation behavior of the soy proteins on heating as a function of pH, as indicated by the different protein compositions of the dissolved protein after heating. At pH 3-5 all protein seems to participate in the network, whereas at pH >5 less protein and especially fewer acidic polypeptides take part in the network, coinciding with less stiff gels. At pH 7.6, extensive rearrangements in the network structure took place during prolonged heating, whereas at pH 3.8 rearrangements did not occur.

摘要

研究了pH值和离子强度对大豆分离蛋白（SPI）凝胶形成及凝胶性质的影响，以及与变性和蛋白质聚集/沉淀的关系。在所研究的所有pH值和离子强度条件下，变性被证明是凝胶形成的先决条件。凝胶在pH>6时表现出低硬度，在pH<6时表现出高硬度。这可能是由于加热时大豆蛋白的缔合/解离行为随pH值变化所致，加热后溶解蛋白的不同蛋白质组成表明了这一点。在pH 3-5时，所有蛋白质似乎都参与了网络结构，而在pH>5时，参与网络结构的蛋白质较少，尤其是酸性多肽较少，这与凝胶硬度较低相吻合。在pH 7.6时，长时间加热过程中网络结构发生了广泛的重排，而在pH 3.8时则未发生重排。