Effect of different levels of carbohydrates on the degree of hydrolysis of fish silage

Abstract

Fermented silage production by Lactic Acid Bacteria (LAB) represents a low cost method for the preparation of food and feed products characterized by hygienic quality and improved shelf life. The present study aimed to compare the effect of different levels of fermentable carbohydrate on the microbial level and the degree of hydrolysis in fermented fish silage from whole fish and dressed fish. Fermented fish silage was prepared with different levels of jaggery (w/w) i.e., 5%, 10% and 15% viz., type I type II and type III respectively. The study indicated that pH values decreased in all the samples during the period of ensilation except in type I sample which showed a higher pH after four days. Since the type I silage was spoiled at an early stage it. is. evident that 5% jaggery is not sufficient for proper preservation through fermentation. But in type II and type III, the changes in pH and degree of hydrolysis do not show significant difference during ensilation. The bacteriological results also indicate that the fermentation patterns of both type II and type III are almost same. Hence it is evident that for successful Lactobacillus fermentation of tilapia 10%, jaggery is sufficient either in whole condition or in dressed condition.