EFFECT OF PRE-TREATMENTS AND DRYING METHODS ON DRYING CHARACTERISTICS OF GINGER

Y. PREMALATHA¹, PURNIMA MISHRA²*
¹Department of Horticulture Engineering, College of Horticulture, Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad, 500030, India
²Department of Horticulture Engineering, College of Horticulture, Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad, 500030, India
* Corresponding Author : drpurnimamishra@gmail.com

Received : 16-03-2019     Accepted : 29-03-2019     Published : 30-03-2019
Volume : 11     Issue : 6       Pages : 8150 - 8153
Int J Agr Sci 11.6 (2019):8150-8153

Keywords : Pre-Treatments, Drying and Ginger
Conflict of Interest : None declared
Acknowledgements/Funding : Acknowledgement / Funding: Authors are thankful to Department of Horticulture Engineering, College of Horticulture, Sri Konda Laxman Telangana State Horticultural University, Rajendranagar, Hyderabad, 500030, India
Author Contribution : All authors equally contributed

The present investigation on effect of pre-treatments and drying methods on drying characteristics of Ginger was carried out at P.G. Laboratory, College of Horticulture, Sri Konda Laxman Telangana State Horticultural University (SKLTSHU), Rajendranagar, Hyderabad, during 2016-17. The design adopted in the study was Factorial Completely Randomized Design (FCRD) with pre-treatments, potassium meta bisulphate (KMS) 0.2 % (w/v), ascorbic acid 0.1 % (w/v), citric acid 1.5 g/l and control. Different drying methods namely, microwave oven drying, solar cabinet drying, hot air oven drying and open sun drying and their combination with pre- treatments were used in the study. The drying methods, pre-treatments and their combinations were found to have significant effect on drying characteristics of Ginger slices. Among drying methods, microwave oven and hot air oven drying methods recorded the final moisture content of 9.61 and 9.68 %, respectively. Solar cabinet and open sun drying had the final moisture content of 10.25 and 10.79 %, respectively. Hot air oven drying method exhibited maximum drying ratio of 9.48. The maximum dry recovery percentage was recorded in respect of microwave drying method. Among pre-treatments, KMS (0.2 %) had the maximum moisture loss of the dried Ginger slices with drying ratio of 9.22 and dry recovery percentage of 1.039 %. Among various treatment combinations the minimum moisture content (9.44 %) and maximum recovery percentage (11.01 %) was recorded with pre-treatment KMS (0.2 %) under microwave drying. The maximum drying ratio was noted with pre- treatment KMS under hot air oven drying method. The drying rate was observed at different time intervals and it was found to be faster at 0.5 and 1 hr intervals as the weight loss of Ginger slices during these intervals was high. As time increased the drying rate showed declining trend. At 0.5 hr the drying rate was faster in microwave and hot air oven drying, whereas in solar cabinet and open sun drying, it was found to be slow. Among the pre-treatments, faster drying rate was observed with KMS (0.2 %). From the results it is concluded that during the process of drying, the Ginger slices did not show constant rate of drying and complete drying took place only in the falling rate period. Further, the treatment combination of potassium meta bisulphate (KMS) under microwave oven drying was found to be the best for most of the drying characteristics of Ginger.

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