Investigating the Effect of Fermented Food on the Nutrient Content of Black Soldier Fly Larvae

Abstract

Food waste is a prevalent issue that afflicts all societies, especially as we tackle the ever-growing problem of world hunger. Even with the rapid advancements in agricultural technology, it seems the demand for food is still unable to be fulfilled, in part due to food wastage. To counter this issue, composting is often sought as an eco-friendly method of recycling spoiled foods into fertilisers. Recently, Black Soldier Flies have risen in popularity due to their larvae’s ability to consume large amounts of waste, producing fertilisers from frass and livestock feed from larvae. To aid this consumption, microorganisms are often introduced to the waste beforehand to catalyse the hydrolysis of complex compounds down to simple organic substances for the larvae to be more easily absorbed. In this study, Black Soldier Fly Larvae were fed food waste consisting of beer grains and okara fermented with Lactobacillus plantarum, a cocktail of Lactobacillus acidophilus, Lactobacillus gasseri and Lactobacillus plantarum and EM1, the industry’s effective microorganisms mix. Out of the three, Lactobacillus plantarum had the most significant effect on the mass, protein content, and nitrogen content of the larvae. Larvae fed with food waste fermented by EM1 had the highest nitrate content, while larvae fed with food waste fermented by the cocktail of Lactobacillus acidophilus, Lactobacillus gasseri and Lactobacillus plantarum had the highest phosphate content. The resulting larvae may be used as plant fertilisers, due to their high nitrate and phosphate contents.