Efect of thermal and non-thermal processing methods on proximate composition, protein digestibility and sensory acceptability of Acheta domesticus flour incorporated bakery products

The present research investigated how thermal (oven drying, roasting, boiling) and non-thermal (freeze-drying, cold-pressing) processing methods afect the proximate composition, In-vitro protein digestibility, and sensory acceptability of bakery products enriched with Acheta domesticus (house cricket) flour at three substitution levels (10%, 20%, and 30% w/w). Cricket specimens were sourced from a commercial farm in Chiang Mai Province, Thailand, and processed using five diferent methods before milling into flour. Proximate analysis showed that freeze-dried cricket flour had the highest crude protein content (67.4 g/100 g), while boiled samples recorded the lowest (55.8 g/100 g). Moisture content ranged from 2.58% in freeze-dried samples to 8.93% in boiled specimens. In-vitro pepsin digestibility was highest in roasted flour (84.7%) and lowest in raw unprocessed flour (71.3%). Bread and cookie formulations were prepared at 10%, 20%, and 30% cricket flour substitution levels. Sensory evaluation using a 9-point hedonic scale with 48 semi-trained panelists indicated that products containing 10% freeze-dried cricket flour received the highest overall acceptability scores (7.83±0.41 for bread and 7.91±0.38 for cookies). Products with 30% substitution received lower acceptability scores owing to darker colour and stronger flavour. Protein content of finished bakery products rose proportionally with cricket flour inclusion, climbing from 11.2% in control bread to 22.8% in 30% freeze-dried flour bread. Freeze-drying and roasting proved the most efective methods for preserving protein content while achieving consumer acceptance, supporting the viability of A. domesticus flour as a protein-enrichment ingredient for bakery applications.