Effects of relative humidity and temperature on small scale peach fruit drying using a tunnel solar dryer: a case study of peach fruit produced by small scale farmers in the midlands of Kwazulu-Natal, South Africa

Abstract

The study investigated the relationships between tunnel and ambient temperature and relative humidity (RH) and their effects on the performance of a tunnel solar dryer tested by drying peach slices. The temperature and RH showed an inverse proportion because if the ambient temperature increased, both the tunnel and ambient RH dropped. There was a direct proportion between the increasing ambient temperature and increased tunnel temperature. The use of treatment such as ascorbic acid or lemon juice did not have a significant effect on the overall drying between the yellow and white landraces. Ascorbic acid had a tendency to perform better than lemon juice which was also better than the untreated slices in terms of the taste and overall acceptability of the dried products. White peach slices were of better quality than yellow slices. It was concluded that solar drying is possible in the Midlands region. Extension officers and researchers can work hand in hand in partnerships with communities in implementing old and cheap but ignored technologies such as this method of food drying.

Keywords: Ambient temperature, ambient RH, tunnel RH, tunnel temperature, lemon juice, ascorbic acid