The production of soluble fish protein solution for use in fish sauce manufacture I. The use of added enzymes

Abstract

Abstract The production of a fish hydrolysate, using plant proteases, which could be added to traditionally fermented fish sauce to increase the total volume without affecting the overall nutritional quality was investigated. The effect of adding bromelain, papain or ficin, on the rate of hydrolysis and the extent of the conversion of insoluble fish protein, to soluble nitrogen was examined. The conditions employed were similar to those used in traditional fish sauce manufacture but both whole and minced Ikanbilis (Stolephorus sp.) were investigated. Measurement of the extent of hydrolysis after 1, 2, 4, 7, 14, 27, 28 and 35 days at 33°C showed that bromelain tended to give slightly better results with some 65% of the protein being hydrolysed. The effect of temperature enzyme, co-enzyme and salt concentrations for the hydrolysis by bromelain were investigated and the optimum conditions established at the pH normally found in fish sauce production. The hydrolysate produced in 18–21 days was comparable to traditional fish sauce in the distribution and concentrations of nitrogenous compounds and had very little aroma. The product could be added to the traditional sauce without affecting its quality.