Effects of blanching on the dehydration characteristics of unripe banana slices dried at different temperature

Abstract

A study was undertaken to examine the effect of blanching on the dehydration characteristics of unripe banana slices blanched and dried at temperatures 50, 60 and 80⁰C. The effects of pretreatments such as blanching, dehydration and combination treatments on the quality of unripe bananas (Musa acuminata) were investigated. The banana fruits were dehydrated at 50, 60 and 80⁰C in a tray dryer at the air velocity of 2-2.5 m/s. The moisture loss from unriped banana slices sample A1, A2 and A3 was higher at blanching temperatures 50⁰C was 7, 6.91 and 6.86 gram and percentage loss in weight was also higher was 2.38, 2.28 and 2.24%, respectively than the blanching temperatures 50 and 60⁰C The drying rates of all treatments were high at drying temperature 50⁰C when the moisture content was highest then decreased rapidly. The overall drying rate of banana after application of dehydration was found to be significantly (P<0.05). The level of total sugars, vitamin C and pH were significantly higher in the blanching process followed by the combined blanching and dehydration. Therefore, combined blanching and dehydration could be used as a pre-treatment to produce high quality dried banana slices where the banana fruits are produced in surplus annually.