Effect of drying methods on the biochemical and functional qualities of ready-to-mix sweet pumpkin powder (Cucurbitaceae)

With their convenient packaging and nutrient density, vegetable-based products are increasingly popular in contemporary convenience-focused diets. This study evaluated the physicochemical, proximate, functional and colour characteristics of sweet pumpkin (Cucurbita moschata Duchesne) powder for ready-to-mix applications, using three different drying techniques: tray drying (TD), freeze drying (FD) and vacuum drying (VD). Freshly made pumpkin puree (PP) was subjected to each drying method at the Department of Food Technology, School of Engineering, Avinashilingam Institute, Coimbatore. The resulting powders, as well as the original wet PP, were analysed for moisture content, protein, fat, fibre, ash, carbohydrate, pH, water activity, viscosity, titratable acidity and colour (L*, a* and b*) using standard AOAC methods. The results indicate that each drying method significantly altered the proximate composition of the PP compared to its wet-cured state (85.2 % moisture). Freeze-dried pumpkin powder exhibited the highest L* (74.82) and b* (30.00) values. It retained a higher percentage of carbohydrate (73.82 %) and dietary fibre (8.91 %), along with favourable carotenoid-associated colour attributes, indicating minimal thermal degradation. Vacuum-dried pumpkin powder showed the lowest water activity (0.298), suggesting increased microbial stability and shelf life.