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

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.

Automated summary

Older black soldier fly larvae have higher ash, fat, and chitin content, while lower in moisture and protein compared to younger larvae. Freezing is preferred as the killing method, resulting in lighter colored larvae than blanching.