A STUDY ON THE EFFECTS OF PRETREATMENT AND TEMPERATURE ON LYCHEE BY DRYING

Abstract

A Study on processing method to solve the ploblems of keeping an excessive amount of fruits such as lychee in the growing districts in the north of Thailand. The method included processing technique and storage. We proposed to study drying mehtod to store the excessive production of the lychee.

The lychee were pretreated by different blanching methods prior to drying under the three temperature levels of 60 °C, 70 °C and 80°C. Pretreatments did not effect on the quality of dried lychee. Quality evaluation by sensory tests and storage life showed best quality for lychee pretreated by blanching in boiling sodium hydroxide solution. Sulphuring and drying at 60°C and the Munsell system of color notation of dried lychee and storage for 6 months changed from yellow-orange of 7.5 YR 6/10 and 10 YR 7/10 to orange-yellow of 7.5 YR 4/6 and 7.5 YR 6/8.