Influence of drying methods on the physicochemical, volatile profile, and sensory characteristics of chip formulations prepared from discarded prawns

Prawn processing generates discards with nutritional value and valorisation potential, including prawns rejected during commercial grading for size or appearance. The growing demand for ready-to-eat foods presents an opportunity to valorise them as dehydrated snacks; however, information on the development of such products remains limited. Therefore, this study evaluated the effects of formulation and drying method (conventional drying, CD, and freeze-drying, FD) on the final characteristics of prawn chips. Four formulations were developed: a control containing 99% discarded prawn meat (C), and three formulations containing 56% each, prepared with rice flour (RF), potato starch (PS), or rice flour and mashed potato (RFPM). All formulations were subjected to both drying methods, and their physicochemical, colour, textural, and volatile properties were evaluated, together with sensory responses using JAR and penalty analyses. CD samples showed higher mean a* (16.6), b* (26.2), and C* (31.1) values and greater differentiation among formulations in colour and mechanical resistance, whereas FD produced lighter ( L* = 84.5), more brittle chips with lower moisture content. CD samples also showed a greater abundance and diversity of volatile compounds, particularly aldehydes (hexanal: 66.8 mg/kg; nonanal: 47.0 mg/kg) and pyrazines (up to 11 mg/kg). JAR analysis showed that responses at the JAR level ranged from 9 to 62% of consumers, depending on the attribute, formulation, and drying method. Penalty analysis showed that RFPM-FD had the lowest penalty for overall liking. The drying method significantly influences the physicochemical and volatile properties, whereas sensory responses depend on the combination of these methods with the type of formulation, with RFPM-FD being the best-performing option among those evaluated.