Effect of pretreatments and temperature on chemical properties of sweet potato flour

Abstract

In this study slices of sweet potato were pretreated with different pretreatments such as; 0.1% w/v potassium metabisulfite (KMS), 1% w/v calcium chloride (CaCl2) and blanching at 80 °C for 5 min. Pretreated sweet potato slices were dried in a mechanical tray dryer at 50, 55, 60 and 65°C simultaneously at constant drying air velocity of 2 m/s in drying chamber. The dried samples were cooled at normal room temperature and grind. After grinding the chemical properties like protein, starch, total sugar, total soluble solids, ash, fiber and colour were studied. Protein temperature. Starch content was found maximum for KMS pretreated sample and decreases with increase in drying content was found maximum for control sample at 60 °C followed by CaCl2, KMS and hot water blanching. Total sugar content was found maximum for CaCl2 pretreated sample at 60 °C. Total soluble solids (TSS) was found increases with increase in drying temperature and found maximum for CaCl2 pretreated sample at 65°C, Ash content was found maximum for CaCl2 pretreated sample and decreases with increase in drying temperature. Fiber content was ranged from 0.10 to 0.18 per cent.