The Quality of Elephant Ginger Dried by Using Modified Hohenheim Dryer under Tropical Climate

Abstract

The objective of the study was to determine the quality of elephant ginger (Zingiber officinale) dried by using a modified Hohenheim dryer designed based on the Hohenheim type tunnel dryer at University of Kassel, Germany. Drying is the oldest method could be used to extend the shelf-life of the product, and the thickness of the material is one of the factors that will influence the drying process. The study was conducted under the tropical climate, in Banda Aceh, Indonesia. The elephants ginger were sliced at different thickness of 3, 4 and 5 mm. Research parameters included solar irradiation, temperature, relative humidity (RH), drying time, drying rate, moisture content, ash content, yield, and colour. To assess the consumer acceptance to the dried ginger, a consumer test was also run to 25 respondents by using hedonic scale on the colour and flavour properties. The study showed that the drying of elephant ginger by using a modified Hohenheim dryer was promising to apply at slice thickness of 3 mm under the tropical climate. The average daily solar irradiation was 403.2 W/m² and the average temperature of drying chamber was 49.5˚C, and the total drying time was 7h. The drying curve of ginger did not follow the ideal drying rate curve; therefore, the modification of the dryer is still needed to improve its performance. However, the quality of dried ginger was good since it had met the export standard for moisture. Nevertheless, the ash content should be reduced to meet this standard by pilling the tuber. According to the sensory analysis, the respondents preferred the colour of ginger dried at slice thickness 3 mm to 4 and 5 mm, but they preferred the flavour of both slice thickness 3 and 4 mm to 5 mm. The colour properties at slice thickness of 3 mm were R-value by 204, G-value by 187, B-value by 119, L-value by 76, a-value by -3 and b-value by 36 and the colour properties among different slice thickness of dried ginger were strongly explained by b-value.