Campbell Lydia, Euston Stephen R, Ahmed Mohamed A
School of Life Sciences, Heriot-Watt University, Edinburgh EH14 4AS, Scotland, United Kingdom.
School of Life Sciences, Heriot-Watt University, Edinburgh EH14 4AS, Scotland, United Kingdom.
Food Chem. 2016 Mar 1;194:1230-7. doi: 10.1016/j.foodchem.2015.09.002. Epub 2015 Sep 2.
This paper investigates the sensory acceptability and textural properties of leavened wheat bread and sponge cake fortified with cow protein isolates that had been denatured and glycated by thermal treatment. Defatted cowpea flour was prepared from cow pea beans and the protein isolate was prepared (CPI) and thermally denatured (DCPI). To prepare glycated cowpea protein isolate (GCPI) the cowpea flour slurry was heat treated before isolation of the protein. CPI was more susceptible to thermal denaturation than GCPI as determined by turbidity and sulphydryl groups resulting in greater loss of solubility. This is attributed to the higher glycation degree and higher carbohydrate content of GCPI as demonstrated by glycoprotein staining of SDS PAGE gels. Water absorption of bread dough was significantly enhanced by DCPI and to a larger extent GCPI compared to the control, resulting in softer texture. CPI resulted in significantly increased crumb hardness in baked bread than the control whereas DCPI or GCPI resulted in significantly softer crumb. Bread fortified with 4% DCPI or GCPI was similar to control as regards sensory and textural properties whereas 4% CPI was significantly different, limiting its inclusion level to 2%. There was a trend for higher sensory acceptability scores for GCPI containing bread compared DCPI. Whole egg was replaced by 20% by GCPI (3.5%) in sponge cake without affecting the sensory acceptability, whereas CPI and DCPI supplemented cakes were significantly different than the control.
本文研究了用经热处理变性和糖化的牛分离蛋白强化的发酵小麦面包和海绵蛋糕的感官可接受性和质地特性。从豇豆中制备脱脂豇豆粉，并制备分离蛋白（CPI）并进行热变性（DCPI）。为制备糖化豇豆分离蛋白（GCPI），在分离蛋白之前对豇豆面粉浆进行热处理。通过浊度和巯基测定，CPI比GCPI更容易发生热变性，导致溶解度损失更大。这归因于GCPI更高的糖化程度和更高的碳水化合物含量，如SDS-PAGE凝胶的糖蛋白染色所示。与对照相比，DCPI和GCPI在更大程度上显著提高了面包面团的吸水性，从而使质地更柔软。与对照相比，CPI导致烘焙面包的面包心硬度显著增加，而DCPI或GCPI导致面包心显著更软。用4%的DCPI或GCPI强化的面包在感官和质地特性方面与对照相似，而4%的CPI则有显著差异，将其添加水平限制在2%。与DCPI相比，含GCPI的面包有更高感官可接受性得分的趋势。在海绵蛋糕中，用20%的GCPI（3.5%）替代全蛋，不影响感官可接受性，而添加CPI和DCPI的蛋糕与对照有显著差异。
