The effect of proteinase inhibitors in food protein hydrolysis by digestive proteinases of white shrimp (Penaeus vannamei) larvae

Abstract

This study describes the digestive capacities of 10-day-old white shrimp postlarvae (PL10) and how some inhibitors of proteinases affect the digestion of protein in aquafeeds by using in vitro hydrolysis techniques. Biochemical data showed eight active proteinases in the PL10 hepatopancreas extract. Enzymes belong to the metallo- and serine-proteinase classes. The effect of inhibitors present in protein ingredients and aquafeeds on PL10 proteinases showed that ovalbumin alone and in commercial microcapsules yielded a significant inhibition in proteolytic activity of PL10 hepatopancreas enzymes. The capacity of PL10 proteinases to hydrolyse the protein fraction within different sources and microcapsules was demonstrated by two in vitro approaches, the pH-stat (degree of hydrolysis, DH) and electrophoresis (coefficient of protein degradation, CPD). It was shown that PL10 proteinases hydrolyse, in different extent protein sources and microcapsules. Casein, cuttlefish meal and feeds containing these ingredients are quickly hydrolysed. By contrast, ovalbumin and microcapsules containing ovalbumin are not hydrolysed. © 2006 Society of Chemical Industry.