Convective Hot Air Drying of Musa nana Linn. by LPG and Electrical Heating : Drying Kinetics, Quality and Energy Consumption การอบแห้งกล้วยเล็บมือนางด้วยการพาความร้อนจากก๊าซหุงต้มและ พลังงานความร้อนจากไฟฟ้า : จลนพลศาสตร์ คุณภาพและความสิ้นเปลืองพลังงาน

Abstract

The main objective of this work is to investigate suitable strategy for Musa nana Linn. banana (Leb muea nang) drying with liquified petroleum gas (LPG) and electric hot air (HA) heating. The Musa nana Linn. banana drying experiments were carried on under the conditions of drying temperature ranging of 55-70 °C. Initial moisture content and average desired final moisture content of banana was in range of 250-300% and 20-25% dry-basis, respectively. The experimental results showed that the drying rate of banana sample depended on drying temperature. The specific energy consumption of the banana drying at high temperature was relatively low compared to those drying with low drying temperature. According to the physical qualities analysis in terms of colorness, percentage of shrinkage and sensory evaluation, the results showed that dried Musa nana Linn. banana with LPG has no significance in colorness measurement compared to the dried banana sample by electric heating. In contrast, percentage of shrinkage of the dried banana using LPG was slightly higher than the dried banana using electric heating. For sensory evaluation, the results showed that an overall acceptability of dried banana with LPG and Electric heating were insignificantly different from the reference dried banana by conventional heating (p < 0.05). In addition, the overall acceptability of dried banana was in moderate scale.