INTERMITTENT AND STEPWISE DECREMENTAL MICROWAVE POWER DRYING OF GREEN LEAFY VEGETABLES.
Loading...
Date
2019-07-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra.
Abstract
Green Leafy Vegetables (GLVs) are gold mines of micronutrients and most affordable source of nutrients required for healthy and disease free body, but are highly perishable due to high moisture content. There is a need to preserve the nature’s storehouse of nutrients through convenient processing techniques. The energy efficiency of the process and quality of dried products are two key factors in food drying. Hence an investigation was undertaken to study the dehydration of green leafy vegetables like Dill leaves, Coriander, Fenugreek, Curry leaves and Mint leaves using Intermittent and Stepwise Decreasing Microwave Power Drying (ISDMD) to get quality dried food in very short drying time. Intermittent Drying helps in reducing the energy consumption as well as helps in retention of micronutrients due to less exposure to microwave field. The treatment of decreasing power of microwave field was given to reduce heat stroke to leafy vegetables. The dill leaves were optimally dried at decreasing power of microwave field viz., 900W, 720W, 540W, 360W, 180W, respectively with 75 s ON time and 36 s OFF time, at each level of power prescribed. The Coriander, Fenugreek, Curry leaves and Mint leaves were optimally dried at decreasing power of microwave field viz., 900W, 720W, 540W, 360W, 180W, respectively with 108 s ON time and 75 s OFF time, with 105 s ON time and 60 s OFF time, with 70 s ON time and 32 s OFF time and with 70 s ON time and 39 s OFF time for respective vegetables, at each level of power prescribed. The OFF time during drying helps in retention of colour with maximum nutrient. This drying process improves product quality and enables the chemical treatment free drying. The total drying time required for Intermittent and Stepwise Decreasing Microwave Power Drying (ISDMD) of Dill leaves, Coriander, Fenugreek, Curry leaves and Mint leaves were 9.25 min, 15.33 min, 13.75 min, 8.5 min and 9.08 min, respectively. The nutritional components like chlorophyll, protein, calcium, iron, vitamin C and vitamin A were maximally retained to extent up to 90 % even after drying. The dried product could be safely stored at accelerated storage condition of 95 % RH and 42 ±1 °C, while packed in 75 micron HDPE for three weeks, whereas the predicted shelf life at 30°C and 65% RH was estimated to be around two and half months for all selected five dried vegetables.
Description
The presentation investigation the intermittent and stepwise decremental microwave power drying of green leafy vegetables viz., dill leaves, fenugreek leaves, coriander leaves, mint leaves and curry leaves was performed. The least time consuming and high quality yielding process of microwave drying for the selected green leafy vegetables was developed. The shelf life of resultant dried green leafy vegetables was determined and predicted shelf life was calculated. The quality parameters such as chlorophyll content, protein content, vitamin A, vitamin C, calcium and iron content were evaluated.
Keywords
null
Citation
SEDANI, SEJAL RASIKLAL. (2019). Intermittent and stepwise decremental microwave power drying of green leafy vegetables. Department of Process and Food Engineering, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Tech. 2019. Print. xv, 91p. (Unpublished).