Studies on Effect of Slice Thickness and Temperature on Drying Kinetics of Kothimbda (Cucumis Callosus) and its Storage

Abstract

Cucumis callosus (Rottl.) Cogn (Cucurbitaceae) is very common throughout the India and commonly known as “Kothimbda ” in Gujarat. Kothimbda is rich source of vitamin C (19.99 mg/100 g) to human beings. The Kothimbda slice was dried in Industrial tray dryer with three levels of drying temperature (50, 60 and 70oC) with constant air velocity at 1.5 m/sec and in solar cabinet dryer also with three levels of thickness (3 mm, 5 mm and 7 mm). The observations on reduction in weight were taken regularly with increase in time and were evaluated in terms of drying characteristics. Three drying models i.e. Page, Henderson and Pabis and Logarithmic were tested for their validity. The values of coefficient of determination (r2) for all the three models under all the treatments were found to be above 0.9, suggesting good fit of the observations. Though, the value of r2 under the Logarithmic Model was more followed by page and Henderson and Pabis, indicating the Logarithmic model more reliable for prediction and found best fitted. The temperature and slice thickness affected significantly on the ascorbic acid content during drying of Kothimbda slice. During storage observations in terms of ascorbic acid were recorded at 15 days interval. The ascorbic acid content of the stored dried Kothimbda powder was decreasing with the increase in storage period under room temperature storage. The loss in ascorbic acid during storage was minimum in the powder packed in Glass bottle followed by HDPE bag and Aluminum Coated P.P. bag.