Optimisation of ready-to-cook chayote slices using pilot scale vacuum drying process

Abstract

Chayote (Sechium edule) fruits have very high moisture content and very soft skins, thus susceptible to spoilage and mechanical damage. Furthermore, due to a lack of suitable storage, transport and processing facilities, huge losses are incurred in terms of quality and quantity. Therefore, the study was conducted to optimise the process parameters of vacuum drying of chayote slices to produce a good quality dehydrated product. The experiments used slice thicknesses of 1, 3, and 5 mm at different temperatures (54 to 66°C). From the analysis using full factorial design and Duncan’s multiple range tests, it was observed that the optimum responses (final moisture content, rehydration ratio, energy consumption, production rate, and total cost) were obtained during vacuum drying of 1 mm chayote slices at 58°C. The results were at par with the treatment consisting of vacuum drying of 3 mm chayote slices at 58°C. From experience, slicing the chayote to 1 mm thickness was too difficult; hence, treatment at 58°C and 3 mm slice thickness may be considered as optimum process condition, which produced dried product with a moisture content of 3.5% at a production rate of 1.662 g d.p./h and had a rehydration ratio of 5.833.