Comparison of microwave and vacuum oven drying on the amino acid composition and antioxidant properties of black soldier fly (Hermetia illucens) prepupae

Abstract

Hermetia illucens or black soldier fly (BSF) is one of the edible insects with the potential to replace animal protein in feed. This study is aimed to compare the effect of microwave oven drying and vacuum drying on its biochemical, antioxidant and physicochemical properties of BSFP to produce shelf-stable animal feed. BSF larvae were fed with fruit waste until prepupal stage and subsequently the prepupae were harvested for drying process using microwave-oven drying (MD-BSFP) and vacuum-oven drying (VD-BSFP). Based on the experimental result, the crude protein of VD-BSFP (31.00%) was higher than MD-BSFP (16.90%) which was significantly different at p < 0.05. Furthermore, the proportion of EAA to total amino acids (E/T) attained using MD-BSFP (24.64%) was significantly higher than that of VD-BSFP (7.86%). In addition, VD-BSFP (12.0 ± 3.0%) had higher free radical scavenging activity than MD-BSFP (5.7 ± 0.2%) at p < 0.05. In conclusion, VD is more preferable than MD as a drying procedure to produce BSFP powder with lower moisture content, higher protein content and antioxidant properties.