Solar drying of West Indian ginger (Zingiber officinale Roscoe) rhizome using a wire basket dryer

A wire basket dryer (1.8 m × 0.9 × 0.2 m) was used to dry sliced (0.15 cm) West Indian ginger (Zingiber officinale Roscoe) rhizome to an acceptable moisture content of 10.2% (dry weight basis) over a 3 day period. The optimum charge size was 14.97 kg, with a packing density of 462.04 kg m−3 and a specific drying rate of 0.446 h−1. The quantities (determined by high-pressure liquid chromatography) of the main pungent principles (gingerol and shogaol) extracted from fresh, non-steam-distilled solar-dried and steam-distilled solar-dried ginger rhizomes showed increases of 0.068, 0.46 and 0.67 g [per 100 g (dry weight basis)], respectively, with a decrease in the oleoresin quality (reflected in pungency profile) of the same order.