The Development of Ginger Drying Using Tray Drying, Heat Pump–Dehumidified Drying, and Mixed-Mode Solar Drying

Abstract

Mature ginger was pretreated by soaking in citric acid prior to drying in a single layer in a tray and heat pump dehumidified dryer at three temperatures of 40, 50, and 60°C and in a mixed-mode solar dryer at 62.82°C and a radiation intensity of 678 W/m². The drying data were applied to the modified Page model. Diffusivities were also determined using the drying data. Quality evaluation by color values, reabsorption, and 6-gingerol content showed best quality for ginger with no predrying treatment and dried at 40°C in a heat pump–dehumidified dryer. At drying temperature of 60 to 62.82°C, no pretreated dried ginger from mixed-mode solar dryer provided the shortest drying time and retained 6-gingerol as high as heat pump–dehumidified dryer.

Keywords:

• 6-Gingerol
• Ginger
• Heat pump–dehumidified dryer
• Mixed-mode solar dryer
• Tray dryer

ACKNOWLEDGEMENTS

The authors acknowledge Postharvest Technology Innovation Center, Khon Kaen University, and Khon Kaen University for their financial support throughout this research.

Notes

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^{a, b} Superscripts are significantly different (p ≤ 0.05).

^{a– j} Superscripts are significantly different (p ≤ 0.05).

^{a, b} Superscripts are significantly different (p ≤ 0.05).

^{a, b} Superscripts are significantly different (p ≤ 0.05).