OPTIMIZATION OF FOAMING PARAMETERS FOR THE SUBSEQUENT DRYING OF BLACK SOLDIER FLY (Hermetia illucens) LARVAE

Insects have been underscored as an emerging alternative food source. However, they are highly perishable, requiring fast processing. As drying is one of the main food preservation techniques, it has been widely studied to improve the quality of edible insect materials. Thus, to minimize changes in food and maximize water removal, different drying methods have been investigated, including foam layer drying. In this method, a liquid or pasty material is transformed into a stable foam using foaming agents and incorporating air, followed by drying. In this context, this study determined the optimal conditions for foam formation aiming at the subsequent drying of black soldier fly (Hermetia illucens) larvae (BSFL). For this purpose, the influence of emustab (X1: 1 – 2 g/100 g), maltodextrin (X2: 3 – 4 g/100 g), and whipping time (X3: 9 – 15 min) on BSFL foam properties (density, stability, porosity, and overrun) was analyzed according to a central composite design (23). The pre-pupal BSFL were cold processed in an extruder resulting in a pasty liquid that was centrifugated to obtain the aqueous/solid fraction used for foam processing in a planetary mixer. The central composite design generated 12 assays. For each response, a second-order polynomial equation was considered to represent the experimental data. The selected conditions were validated using three independent experimental replicates, and the values obtained were compared with those predicted by the models. The results showed that the optimum conditions for foam preparation were X1(1.5 g/100 g), X2(4 g/100 g), and X3(15 min). Under these conditions, the density, stability, porosity, and overrun were 409.69 kg/m3, 72.49%, 60.51%, and 153.64%, respectively. Thus, this study provides optimal parameters to obtain foams of low density, high stability, porosity, and overrun, which may be further successfully used to achieve high-quality dry materials from black soldier fly larvae.