Techno-functional properties of black soldier fly (Hermetia illucens) larvae

Abstract

Quality, nutritional and techno-functional properties of whole black soldier fly larvae (BSFL) were investigated to determine its potential as a food ingredient. The effect of age, feed and killing method (blanching or frozen) on these characteristics were determined; all three factors influenced the characteristics investigated. The BSFL were freeze dried and milled into a powder and analysed for physical (larvae size, pH, colour, proximate composition) and techno-functional properties (water absorption capacity, lipid absorption capacity, emulsifying activity, emulsifying stability, and gel formation). Older larvae were found to have a higher ash, fat, and chitin content, whilst having lower moisture and protein contents than the younger larvae (P<0.05). The pH of the BSFL ranged from 6.79 (frozen) to 8.94 (blanched), with blanching causing a lighter coloured BSFL than freezing. The water absorption capacity of the BSFL ranged from 56.27 to 80.77% and the lipid absorption capacity ranged from 50.83 to 68.62%, both of which are lower than that of other insect species. Five-day aged frozen larvae could form a gel at 5% inclusion, whilst blanching had a negative effect on gel formation and required an inclusion of 30% BSFL to form a gel. Emulsion capacity (EC) (43%) and stability (ES) (32%) compared well to other insect species; however, blanching had a negative effect on these properties, reducing both EC (10%) and ES (5%). Overall, the results indicate that freezing is the preferred killing method for ingredient functionality and these findings demonstrate some promising potential for BSFL as a functional ingredient.