Studies on microwave assisted high velocity hot air drying characteristics of cauliflower (Brassica oleracea)
Loading...
Date
2015-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
Cauliflower (Brassica oleracea var botrytis) is one of the important cole crop in India, especially in northern states. The high post harvest losses and huge availability during glut demands the cauliflower to preserve so that their useful characteristics can be reaped during unavailability. Among all food preservation methods, dehydration is a easiest and classical method of food preservation. The cauliflower were dehydrated in microwave assisted high velocity hot air drier at five microwave power input of 3, 3.50, 4, 4.50 and 5 min. with five temperatures of 50, 55, 60, 65 and 70o C and five air flow velocities of 1.5, 3, 4.5, 6 and 7.5 m/s. Dehydrated cauliflower were analyzed for rehydration ratio, vitamin C and browning. In order to select a suitable drying model for prediction of the drying kinetics of dehydrated cauliflower, three thin-layer drying models were fitted to the experimental data. Logarithmic model was found best to describe the drying behaviour of cauliflower with highest R2 of 0.9994 and least SEE of 0.0142. Statistical analysis indicated that the drying time was dependent on microwave time, drying temperature and velocity. The total time consumed to dehydrate the cauliflower samples to safe moisture level was 55 to 148 min. The optimum value of microwave time, drying temperature and air velocity for overall drying time of cauliflower were obtained as 4 min., 60o C and 4±1 m/s respectively. Furthermore, the application of Artificial Neural Network (ANN) for predicting the drying time was investigated with 8 neurons in single hidden layer. The results revealed that a network with the log sigm function and back propagation algorithm provided better accuracy in the estimation of overall drying time.
Description
Keywords
null