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[Display omitted] • Supermarket food waste is suitable substrate for rearing black soldier fly larvae. • High waste reduction of supermarket food waste by rearing black soldier fly larvae. • Heat treatment of supermarket food waste is necessary for microbiological safety. • Substrate composition influences the effect of heat treatment on food pathogens. • Heat treatments applied on supermarket food waste did not influence larval growth. Supermarket food waste, constituting 13% of global food waste, can be upcycled as substrate for black soldier fly larvae (BSFL) and converted into larval biomass. Since presence of food pathogens in supermarket food waste is likely, microbiological safety should be ensured when using waste as insect substrate. Heat treatment provides a suitable pre-treatment to reduce microbiological contaminations. This study investigated the effect of different temperature–time combinations on the microbiological safety of supermarket food waste as BSFL substrate. Artificial supermarket food waste without meat and fish (SFW) was inoculated with both Salmonella and Staphylococcus aureus (7.0 log cfu/g) and treated at 50 and 60 °C for 10, 20 and 30 min. While 50 °C was insufficient for adequate pathogen reduction, 60 °C only required 10 min to reduce the Enterobacteriaceae and S. aureus counts to < 1.0 log cfu/g and for absence of Salmonella in 25 g. Heat-treated SFW could be stored for two days at ambient temperature or refrigerated without pathogen growth. Treatment of supermarket food waste containing meat and fish at 60 °C for 10 min caused similar results as for SFW, but S. aureus persisted (2.4 log cfu/g), possibly by protective effects of fat and/or proteins. Finally, BSFL rearing experiments on SFW revealed significantly higher larval mass, bioconversion efficiency and waste reduction than on Gainesville diet, with no notable differences between untreated and heat-treated SFW. Rearing BSFL on supermarket food waste is possible, and unsafe food waste can be heated to obtain safety without eliminating nutrients necessary for rearing. [ABSTRACT FROM AUTHOR]

This study evaluated the production of two black soldier fly larval meals (BSFLMs) when rearing the larvae on brewers' spent grains (BSFLM-B) or a commercially available substrate (BSFLM-C, Gainesville house fly diet). The resulting nutrient composition of the BSFLMs were significantly impacted by the feeding substrates, and they were evaluated as a protein ingredient for red drum, where BSFLM-B and BSLFM-C replaced 65% of the fishmeal protein from the control diet. For a comparative feeding trial, three experimental diets were formulated to be isonitrogenous and isoenergetic. Groups of 12 red drum (~ 5 g) were stocked in each of 15, 38-L aquaria, and the three experimental diets were distributed in a completely randomized block design. The experimental diets were offered for 8 weeks at fixed percentage of the body weight that was weekly adjusted. Red drum fed BSFLM-B diets presented impaired weight gain and feed efficiency when compared to the control group. However, red drum fed BSFLM-C diets had growth performance numerically lower, but it was not statistically different than that of fish fed the control diet. Dietary inclusion of BSFLMs significantly affected the whole-body saturated fatty acid composition, total omega-3 and omega-6, and reduced the mineral profile of red drum. The intestinal microbiota was also affected by the dietary BSFLMs, with possible reduction of the relative abundance of a prominent pathogenic bacterial Flavobacterium spp. The findings of the present study highlight the importance of the nutrition of BSFL prior ingredient manufacturing to be a suitable sustainable replacement of forage fishmeal for carnivorous fish, and the potential nutraceutical properties of BSLFMs to possibly combat enteric pathogenic in industrial conditions. • Feeding substrate affected the nutrient composition of black soldier fly larvae meals (BSFLMs). • Production performance of red drum was impaired by the dietary inclusion of BSFLMs. • Nutrient composition of red drum whole-body was affected by the dietary BSFLMs. • Intestinal microbiome of red drum was affected depending on which BSFLM was offered. [ABSTRACT FROM AUTHOR]