Effects of drying conditions on the physicochemical and functional properties of red- and yellow-fleshed watermelon rinds flour

Abstract

This study aimed to investigate ate the effect of drying conditions (freeze dryingng and hot-air oven drying at 40 and 60°C) onon the physicochemical and functional proper perties of red and yellow-fleshed watermelon rind rind flour. In comparison among the drying proceocesses used in this study, freeze drying method re resulted in flour with better quality in terms of colour, pH, total titratable acids, total sugar, total starch and digestible starch. Howev ever, results on the physicochemical and functional nctional attributes of the flours revealed that hot--air dried flour had higher values for bulk density,, water absorption capacity, oil absorption ca capacity and resistant starch than that of the freeze e dried flour. Drying conditions exerted marke marked effects on the properties of watermelon rind flours in this study. 

Keywords: watermelon rind flour; hot-air oven drying; freeze drying; physicochemical properties; functional properties