Cutting-edge insect processing: unlocking the potential for bacterial reduction in black soldier fly (Hermetia illucens) protein

Insects are rising in importance as an alternative animal protein feed source for livestock and pets. Black soldier fly larvae (Hermetia illucens) are one of the most common species in this alternative sector. This is based on their nutritional value, growth potential, high bioconversion ratio, and low environmental impact. The bacterial population in the larvae has been characterized but not the impact of process technology on bacterial reduction. This study focuses on the effect of insect processing on bacterial levels, from the larvae up to the protein feed generated from them. The two common processes, dry and wet processing, are compared with regard to their individual impact on product hygiene. Significant differences were observed between the technologies used for insect processing. In the dry process, a reduction of bacteria in the range of 2.63–3.41 log CFU/g was observable. In wet processing, a higher potential to reduce bacteria in the products was found, resulting in a decrease in bacterial count of 5.68 log CFU/g over the entire process. Both systems have shown different reduction potentials at different process stages. The EU Regulation 142/2011 is set as a legal benchmark in this study. Additionally, we observed a slow recontamination of the protein feed in a storage study over 14 days.