Fundamentals of Food Technology

Functions of proteins

DEFENITION
Digestion & Absorption

• The digestion of proteins takes place in the stomach and intestines. As a result of digestion, the proteins are broken down to amino acids and absorbed.

Gastric digestion

• The proteolytic enzyme present in gastric juice is called as pepsin which acts on proteins in an acid medium and hydrolyse them to simpler compounds known as polypeptides.

Intestinal digestion

• The digestion of proteins is further carried out in the intestines by the action of proteolytic enzymes (trypsin, chymotrypsin and peptidase) present in pancreatic and intestinal juices.
• The polypeptides produced by gastric digestion are hydrolysed to free amino acids by the above enzymes.
• The amino acids are absorbed in the small intestine and enter the blood circulation through the portal vein.