INFLUENCE OF NONENZYMATIC GLYCOSYLATION (GLYCATION) OF PEA PROTEINS (PISUM SATIVUM) ON THEIR SUSCEPTIBILITY TO ENZYMATIC HYDROLYSIS

Abstract

The Maillard reaction, also referred to as nonenzymatically glycosylation (glycation), causes changes to protein structure and occurs in food. The aim of this study was to investigate changes in susceptibility of glycated pea proteins to enzymatic hydrolysis. A pea proteins extract was glycated using different sugars (glucose, fructose, lactose and glucosamine). Then, the physicochemical changes of proteins after glycation in ultraviolet spectra as well as the content of sugars and free amino groups were determined and also separated electrophoretically. Native and glycated pea proteins were hydrolyzed for 120 min with pepsin (one-step hydrolysis) or with pepsin and trypsin (in two-step process). Pea proteins glycated by glucose and lactose were less susceptible to pepsin hydrolysis than the pea proteins glycated by fructose and glucosamine in comparison with native pea proteins. Glycated pea proteins were more susceptible to hydrolysis by pepsin and trypsin in the two-step hydrolysis than the native ones. PRACTICAL APPLICATION Nonenzymatic glycosylation (glycation) of food proteins is used for the improvement of their functional properties. The formed glycoproteins can be characterized by changing biochemical properties, i.e., the susceptibility to the enzymatic hydrolysis or the influence on the growth and survival of the gut microflora. For this reason, investigations on the effect of the glycation of food proteins on their biological properties were necessary from the nutritional and health-promoting point of view.