Effect of solar drying on proximate composition of two varieties of ginger rhizomes for blanched and unblanched treatments

Abstract

Ginger (Zingiber officinale Roscoe) of two verities UG I ('Tafin-Giwa', a yellowish variety with plump rhizomes) and UG II ('Yatsun-Biri', a black or dark variety with small compact rhizomes), were analysed to identify its proximate composition. The effects of drying as a processing technique on ginger were investigated with respect to the proximate composition of the produce. The UG I and UG II were collected, sorted (whole, peeled and unpeeled) and (slice, peeled and unpeeled), and were subjected to Unblanched and Blanched (50℃ at 3,6 and 9 min respectively) treatments and dried using solar dryer for a period of one month. The initial moisture content of UG I and UG II were 71.12% and 72.47% respectively, the final moisture content were reduced to 7.02% SUP (Unblanched) and 5.52% SUP (Blanched at 9 min) for UG I, while that of UG II were 4.82% SP (Unblanched) and 5.85% WUP (Blanched at 3 min). For Carbohydrate content, 61.38% was noted to be the lowest level at Unblanched (Whole peeled), and 68.37% indicates higher CHO content at Blanched 50℃ at 9 min (Split Unpeeled) treatments for UG I samples. Similarly, for UG II, CHO's presence was low at 56.01% for Unblanched (Whole peeled) and high at 76.32% for Blanched on the temperature of 50°C at 9 min (Whole peeled) treatment. Ash content was observed to be low at 4.68% for Blanched 50℃ at 3 min (Split Unpeeled) and high at 6.47% for Unblanched (Whole peeled) treatment for UG I samples, and 3.82% low for Blanched on the temperature of 50°C at 9 min (Split peeled) with higher ash content of 7.69% Unblanched (Split Unpeeled) treatment for UG II samples.