Dehydration-Induced Changes in Physical and Volatile Characteristics of House Cricket (Acheta domesticus) Powder

• Exoskeleton rigidity and cryoprotectants are hypothesised to minimise denaturation. • Reoxygenation of metalloproteins may affect the colour of dehydrated cricket powder. • Freeze-drying may cause off flavours that require masking during reformulation. • Low-odour-threshold compounds occurring after drying may impact on sensory quality. This study evaluated changes in the physical properties of cricket powder during dehydration, under parameters consistent with EFSA scientific opinions and wider international practices. Freeze-drying for 24 h resulted in cricket powder with 3.96 g/100 g moisture content and a w of 0.237. In oven-dried crickets, greatest moisture loss occurred within the first 3 h across all temperatures evaluated. Significant colour changes were noted in dried cricket powders, lightening was attributed to metalloprotein deoxygenation, while increased darkening indicated the occurrence of non-enzymatic browning, supported by the appearance of Maillard reaction products. ATR FT-IR showed significant peak shifts indicating dipole-active vibrational changes, while Amide I deconvolution revealed an unchanged protein secondary structure. Concentration of volatile compounds increased as function of dehydration time, attributable to Strecker degradation, Maillard and lipid oxidation reactions. In conclusion, dehydration alters cricket powder attributes that may require adjustments for optimised processing or subsequent macromolecule extraction.