Use of Peat Extract in the Ensiling of Fisheries Wastes

Abstract

Fish processing wastes, namely minced cod (Gadus morhua) offal and minced male capelin ( Mallotus villosus), were used in two kinds of ensiling (silage making) processes. In one process they were ensiled by the direct addition of acids, and in the other they were ensiled using various carbohydrate sources and bacterial cultures to produce organic acids in situ. Ensiled material was analysed for various components at times throughout its storage period, and monitored for onset of spoilage. It was found that neither prior freezing nor initial heat treatment of capelin had an effect on the preservation effectiveness of the ensiling process. It was concluded that both the addition of formic acid to cod offal and the fermentation of lactic acid bacteria are effective methods of ensiling this material. Peat extracts with a relatively high carbohydrate content were found to be a satisfactory source of carbohydrates for the fermentation of lactic acid bacteria in cod offal silage. However, peat extracts with a relatively low pH were found to be unsatisfactory as a direct source of acid for ensiling.