Chemical changes seen in protein during pelleting : a literature review

Abstract

Pelleting induced changes in protein denaturation with exposure to heat is to milder level. Denaturation of protein showed better digestibility of protein molecule. Change in the secondary structure i.e. alpha helix, beta sheet, beta turn and random coil is seen during pelleting and pressure induced treatment. Secondary structure directly affects the solubility and digestibility of the fractionated protein. Increase in conditioning time highly affect the fragmentation of protein molecule. As the heat is applied the molecular dissociation of the protein molecule lead to fractionated protein of smaller molecular weight. The amount of smaller molecular weight is higher compared to large molecular fraction. Antinutrients level is diminished to certain extent on exposure of heat during pelleting. Some of the amino acids like lysine and cysteine is prone to undergo maillard reaction and form Amadori compound. Degradation of lysine is higher during pelleting. Increase in degradation of lysine rises with shifting of the medium towards alkaline scale.