Quality Assessment of Formulated Osmotically Dehydrated Cashew Apple (Anacardium occidentale L.) Slices Dried using Hot air and Solar Driers

Abstract

Cashew apples are rich in phytochemicals particularly vitamin C and yet are highly underutilized in low technological countries. This study investigated the effect of drying methods on quality attributes of osmotically dehydrated cashew apples. Specifically; nutrient retention, rehydration coefficient, microbial safety and sensory attributes were assessed. Fully matured, ripe and intact fruits were washed, blanched, sliced, and immersed in 70% sucrose before drying on hot air and solar drier. No significant difference (p > 0.05) was observed on carotenoids (0.28-0.33 g/100g), vitamin C (0.73-0.85 g/100g), and tannins (266.59-267.95 mg/100g) in both dried cashew apple slices, except on significantly higher total phenolic (p < 0.05) in hot air-dried slices. During storage at room temperature for 60 days: total phenolic, tannins, and vitamin C were significantly reduced (p < 0.05) in both hot air and solar dried slices; while carotenoids were maintained (p > 0.05) in hot air-dried slices, and slightly reduced (p < 0.05) in solar dried slices. Solar dried slices had better rehydration efficiency compared to hot air-dried ones. Both dried products had similar (p > 0.05) overall acceptability, and zero microbial counts when observed for 60 days. Though solar drying retained less of the desirable nutritive values, it is relatively cheaper and is recommended for use in low resource settings.