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.

中文翻译：

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胃蛋白酶辅助的转谷氨酰胺酶修饰从工业向日葵粉获得的蛋白分离物的功能特性。

利用工业向日葵粉生产食品工业中富含蛋白质的产品是更好，更有效地利用这种农业副产品的替代方法。葵花籽蛋白具有特定的功能特性，但是需要加以改进以扩大其潜力，以作为补充剂，为人类提供高品质的营养产品。本研究的目的是评估低度胃蛋白酶水解和转谷氨酰胺酶（TG）修饰对pH = 2至10的工业向日葵粕蛋白分离物功能的综合影响。三种TG修饰的胃蛋白酶水解物的水解度为0.48分别生产了0.71％和1.72％的TG-PH1，TG-PH2和TG-PH3。三种TG修饰的胃蛋白酶水解产物在3.5至5的pH值下均显示出改善的溶解度。在蛋白质等电点（pI = 4.5）观察到最高的TG-PH3为5。在pH <3和> 7的条件下，向日葵粉蛋白分离物和TG修饰的向日葵粉蛋白分离物的溶解度高于三种TG修饰的水解物。在所研究的整个pH范围内，所有三种TG改性的胃蛋白酶水解物均可显着提高泡沫制造能力（p <0.05）。具有三个水解度的蛋白分离物的胃蛋白酶水解不能改善泡沫稳定性。与蛋白质分离物（pH = 7）相比，TG-PH3在高达80°C的温度下观察到改善的热稳定性。在90°C下，仅对蛋白分离物进行TG修饰即可获得最高的热稳定性。胃蛋白酶水解后再用TG处理可用于生产溶解度提高的向日葵蛋白分离物，