The concept of enzymatic disintegration of nutrients in the upper gastrointestinal tract

Abstract

The aim of the study was to study the effect of salivary amylase on improving gastric protein digestion, as well as the effect of gastric protein hydrolysis on improving fat digestion. The work consisted of two parts, in the first part, in two series, the hydrolysis of proteins under the influence of gastric juice in the presence of starch and the effect of saliva amylase on the change in the total proteolytic activity of gastric juice when using substrates of a mixture of starch and proteins were investigated. In the second part of the work, the lipolytic activity of pancreatic juice with the studied proteins was studied in the presence and absence of bile. From the data obtained, it was found that the use of a mixture of starch with proteins helps to reduce the hydrolysis of proteins by gastric juice. The use of salivary amylase promotes an increase in protein hydrolysis by reducing the formation of starch-protein complexes that prevent the digestion of proteins by gastric juice. All the studied proteins, except gelatin, have an inhibitory effect on lipase in the pancreatic juice; the degree of inhibitory effect of each protein is expressed differently. It depends on their degree of digestion in gastric juice. Thus, the preliminary hydrolysis of proteins by pepsins in the stomach contributes not only to the further improvement of their hydrolysis under the influence of proteolytic enzymes of pancreatic juice, but also to the hydrolysis of fats under the influence of pancreatic lipase. It is concluded that the sequence of nutrient breakdown by enzymes of saliva, stomach and pancreas is primarily aimed at enzymatic disintegration between polysaccharides and proteins, as well as proteins and fats, in order to reduce their interaction and the formation of physical complexes. Thus, secondarily, improve the digestibility of nutrients in the upper gastrointestinal tract. The conceptual assumption of enzymatic disintegration of nutrients in the upper gastrointestinal tract allows us to substantiate the existing sequence of initial digestion of polysaccharides by saliva, as well as the initial digestion of proteins by gastric juice.