Ivanova Petya, Chalova Vesela I, Kalaydzhiev Hristo, Perifanova-Nemska Mariana, Rustad Turid, Koleva Lidia
University of Food Technologies, Department of Biochemistry and Molecular Biology, 26 Maritsa Bulv., BG-4002 Plovdiv, Bulgaria.
University of Food Technologies, Department of Technology of Tobacco, Sugar, Vegetable and Essential Oils, 26 Maritsa Bulv., BG-4002 Plovdiv, Bulgaria.
Food Technol Biotechnol. 2017 Sep;55(3):420-428. doi: 10.17113/ftb.55.03.17.5061.
The utilization of industrial sunflower meal to produce protein-rich products for the food industry is an alternative approach for better and more efficient use of this agricultural by-product. Sunflower meal proteins possess specific functional properties, which however need improvement to broaden their potential as supplements for delivering high--quality products for human nutrition. The aim of the study is to evaluate the combined influence of low-degree pepsin hydrolysis and transglutaminase (TG) modification on industrial sunflower meal protein isolate functionality at pH=2 to 10. Three TG-modified pepsin hydrolysates with the degree of hydrolysis of 0.48, 0.71 and 1.72% were produced and named TG-PH1, TG-PH2 and TG-PH3, respectively. All three TG-modified pepsin hydrolysates exhibited improved solubility at pH between 3.5 and 5.5 as the highest was observed of TG-PH3 at protein isoelectric point (pI=4.5). Sunflower meal protein isolate and TG-modified sunflower meal protein isolate had greater solubility than the three TG-modified hydrolysates at pH<3 and >7. Significant improvement of foam making capacity (p<0.05) was achieved with all three TG-modified pepsin hydrolysates in the entire pH area studied. Pepsin hydrolysis of the protein isolate with the three degrees of hydrolysis did not improve foam stability. Improved thermal stability was observed with TG-PH3 up to 80 °C compared to the protein isolate (pH=7). At 90 °C, TG modification of the protein isolate alone resulted in the highest thermal stability. Pepsin hydrolysis followed by a treatment with TG could be used to produce sunflower protein isolates with improved solubility, foam making capacity and thermal stability for use in the food industry.
利用工业向日葵粕生产富含蛋白质的食品工业产品，是更好、更高效利用这种农业副产品的一种替代方法。向日葵粕蛋白具有特定的功能特性，然而，为了扩大其作为人类营养优质产品补充剂的潜力，这些特性仍需改进。本研究的目的是评估低程度胃蛋白酶水解和转谷氨酰胺酶（TG）修饰对工业向日葵粕分离蛋白在pH=2至10时功能特性的综合影响。制备了三种水解度分别为0.48%、0.71%和1.72%的TG修饰胃蛋白酶水解产物，分别命名为TG-PH1、TG-PH2和TG-PH3。在pH值为3.5至5.5之间，所有三种TG修饰胃蛋白酶水解产物的溶解度均有所提高，其中TG-PH3在蛋白质等电点（pI=4.5）时的溶解度最高。在pH<3和>7时，向日葵粕分离蛋白和TG修饰向日葵粕分离蛋白的溶解度高于三种TG修饰水解产物。在整个研究的pH范围内，所有三种TG修饰胃蛋白酶水解产物的起泡能力均有显著提高（p<0.05）。三种水解度的分离蛋白经胃蛋白酶水解后，泡沫稳定性并未提高。与分离蛋白（pH=7）相比，TG-PH3在高达80°C时的热稳定性有所提高。在90°C时，单独对分离蛋白进行TG修饰可获得最高的热稳定性。胃蛋白酶水解后再用TG处理，可制备出溶解度、起泡能力和热稳定性均有所提高的向日葵分离蛋白，用于食品工业。
