Assessment of the Nutritive Value of Heated Fish Protein Concentrates (FPC) by a Simple In Vitro Pepsin Digestion Procedure

Abstract

Abstract A simple in vitro pepsin digestion procedure with capacity for large numbers of samples has been developed for assessing the nutritive value of FPC in quality control laboratories. In vitro dry matter digestibility (DMD) of autoclaved FPC was significantly correlated with in vivo DMD of the same FPC fed as supplements to wheat gluten diets for rats. Reduced nutritive value caused by autoclaving was not reflected in animal growth until after 4 hr of autoclaving, when the diet contained 4% FPC. Blood plasma and fecal concentrations of lysine and methionine and digestibility data showed that nutritive value of FPC was reduced after shorter periods of autoclaving than was suggested by growth. Reduction of the FPC supplement to 2.5% of diet resulted in nutritive value decreases becoming apparent after shorter autoclaving periods and in the attainment of a significant correlation between in vitro DMD and animal growth criteria.