Effect of Pretreatment and Drying Methods on Physicochemical and Sensory Properties of Dried Kaffir Lime Leaves

Abstract

The objective of this research was to obtain the optimal pretreatment and drying methods in order to improve color and odor of dried kaffir lime leaves. A 3 x 3 factorial design was performed to investigate pretreatment methods (no pretreatment, blanching in magnesium carbonate and blanching in salt solution then soaking in potassium metabisulfite) and drying methods (hot air oven at 50 °C for 6 hours, microwave vacuum at 4,800 watt for 30 min, and fluidized bed at 60 °C for 2 hrs). Result showed that pretreatment and drying methods affected color value L* a* b*, citronellal content and liking scores (p≤0.05). Kaffir lime leaves pretreated with both of blanching in magnesium carbonate and blanching in salt solution then soaking in potassium metabisulfite had citronellal content more than that of no pretreatment. Kaffir lime leaves dried with microwave vacuum drying had citronellal content and liking scores higher than those of the other drying methods. Optimal drying condition for kaffir lime leaves which had the highest citronellal content and liking scores in term of color and odor was blanching in magnesium carbonate and then dried with microwave vacuum at 4,800 watt for 30 min.