Impact of thermal and high-pressure treatments on the microbiological quality and in vitro digestibility of black soldier fly (Hermetia illucens) larvae

Campbell, Mairead; Ortu�o, Jordi; Stratakos, Alexandros Ch.; Linton, Mark; Corcionivoschi, Nicolae; Elliott, Tara; Koidis, Anastasios; Theodoridou, Katerina

Abstract

Black soldier fly larvae (BSFL) are gaining importance in animal feeding due to their ability to upcycle low-value agroindustry by-products into high-protein biomass. The present study evaluated the nutritional composition of BSFL reared on brewer’s by-product (BBP) and the impact of thermal (90◦C for 10/15 min) and high-pressure processing (HPP; 400/600MPa for 1.5/10 min) treatments on the microbial levels and in vitro digestibility in both ruminant and monogastric models. BBP-reared BSFL contained a high level of protein, amino acids, lauric acid, and calcium, and high counts of total viable counts (TVC; 7.97), Enterobacteriaceae (7.65), lactic acid bacteria (LAB; 6.50), and yeasts and moulds (YM; 5.07). Thermal processing was more effective (p < 0.05) than any of the HPP treatments in reducing TVC. Both temperature of 90◦C and pressure of 600 MPa reduced the levels of Enterobacteriaceae, LAB, and YM below the detection limit. In contrast, the application of the 400 MPa showed a reduced inactivation (p < 0.05) potential. Heat-treated samples did not result in any significant changes (p > 0.05) on any of the in vitro digestibility models, whereas HPP showed increased and decreased ruminal and monogastric digestibility, respectively. HPP did not seem to be a suitable, cost-effective method as an alternative to heat-processing for the large-scale treatment of BSFL.

• Journal Article Type: Article
• Acceptance Date: Apr 11, 2020
• Online Publication Date: Apr 14, 2020
• Publication Date: Apr 14, 2020
• Deposit Date: Jun 26, 2021
• Publicly Available Date: Jun 29, 2021
• Journal: Animals
• Electronic ISSN: 2076-2615
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 4
• Article Number: 682
• DOI: https://doi.org/10.3390/ani10040682
• Public URL: https://uwe-repository.worktribe.com/output/7450749