Foam-mat drying of black soldier fly larvae: optimisation of foaming, drying kinetics, and powder characteristics

Desirable conditions for foaming, drying kinetics, and characteristics of black soldier fly larvae (BSFL) powders were studied. Pre-pupal BSFL was fractionated under wet conditions. A pasty liquid, free of fibrous material, was used and adjusted to a moisture content suitable (88%) for foaming. The influence of emustab ( : 1-2 g/100 g), maltodextrin ( : 3-4 g/100 g), and whipping time ( : 9-15 min) on the BSFL foam properties were analysed according to a central composite design (23) with added axials. Optimal conditions for foam preparation ( : 1.5 g/100 g, : 4 g/100 g, and : 15 min) revealed excellent foam properties (density: 409.69 kg/m3, stability: 72.49%, porosity: 60.51%, and overrun: 153.64%). For the drying process, foamed (optimum conditions) and liquid (no additives) samples were compared at different temperatures (40, 60 and 80 °C) to determine the drying kinetics and powder quality. For kinetic modelling, five mathematical expressions were fitted to the experimental data. The Newton, Henderson & Pabis, Page, Logarithmic, and Midilli models were adequate ( > 0.95) to represent the drying kinetics of the BSFL foams and liquids. However, the mathematical models that best described the kinetic curves were those proposed by Midilli and Page ( > 0.99 and < 0.03). In addition, foam dried at 60 °C exhibited excellent powder quality characteristics. Thus, this study provides new alternatives to process protein-rich food and feed (above 54.82%) in short periods with positive economic, social, and environmental impacts.