MICROWAVE DRYING CHARACTERISTICS FOR GINGER ROOT (Zingiber officinale)

Taha, A. T.

doi:10.21608/mjae.2015.98632

MICROWAVE DRYING CHARACTERISTICS FOR GINGER ROOT (Zingiber officinale)

Document Type : Original Article

Author

A. T. Taha

Agricultural Engineering Department, Faculty of Agric., Menoufia University, Egypt.

10.21608/mjae.2015.98632

Abstract

This experiment was carried out at Agricultural Engineering DepartmentMinofiya University to study microwave drying characteristics for ginger root. Five microwave drying powers (180, 360, 540, 720 and 900 Watt) and four levels of ginger thickness (0.5, 1, 1.5 and 2 cm) were used. Drying characteristics and quality aspects of the dried ginger were studied. The drying time to achieve the save storage moisture content was 14 minutes at 900 Watt with 0.5cm thickness. Total phenolic content of fresh ginger was 0.40 mg/g.d.m. and the highest phenol content in dried ginger was detected at the 900 Watt power with 1.5cm thickness, and the lowest phenolic value was recorded at 180 Watt with 2 cm thickness. The fresh ginger hardness ranged from 0.5 to 1 kg /cm² and the highest hardness of dried ginger was 6 kg /cm² at both 720 and 900 W with all thickness. The highest drying efficiency of ginger slices was 78% at 720 and 900 Watt with 2 cm thickness and the lowest efficiency (less than 10%) was recorded at 180 Watt with all used thicknesses (except at 2 cm. thickness). The highest value of energy consumption (10.2 MJ) was detected at 180 Watt and 2 cm thickness, while drying at 900 Watt with both 0.5 and 1 cm. thickness represent the lowest energy consumption (1.13 MJ). Veirma model can be used to describe the behavior of microwave drying of ginger, which gave the best results.
Key word: microwave, drying, ginger, thickness

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