~ 732 ~ International Journal of Chemical Studies 2019; 7(2): 732-737 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2019; 7(2): 732-737 © 2019 IJCS Received: 14-01-2019 Accepted: 18-02-2019 Meenakshi Trilokia Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Monika Sood Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Julie D Bandral Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Shafia Ashraf Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Mehnaza Manzoor Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Correspondence Meenakshi Trilokia Division of Food Science and Technology, Faculty of Agriculture Sher-e-Kashmir, University of Agricultural Sciences and Technology of Jammu, Main Campus Chatha, Jammu, Jammu and Kashmir, India Changes in quality of microwave blanched vegetables: A Review Meenakshi Trilokia, Monika Sood, Julie D Bandral, Shafia Ashraf and Mehnaza Manzoor Abstract Blanching is a heat treatment widely applied in the agro-food sector and particularly important in the processing of green vegetables. It increases the shelf life of fruits and canned food. The main objectives of blanching are: to inactivate the enzymes, prevent possible deterioration reactions, off-flavours and undesirable changes in colour; to reduce microbial load and to soften tissues to obtain products with specific texture. There are different types of blanching. Currently, hot water blanching is commercially adopted blanching method as it is simple and easy to implement. However, consumes large amount of water. In addition, water-soluble nutrients, such as vitamins, flavours, minerals, carbohydrates, sugars, and proteins, can leach out into the blanching water. As a further consequence, lowers somewhat the mass of vegetables thus process profitability can be affected by overtreatment. To mitigate those shortcomings, several novel blanching technologies have been developed and reported, e.g., Microwave blanching. It is considered as a dry technique, the volume of wastewater generated could be diminished and therefore losses of water-soluble nutrients could be minimized. It allows for efficient heat transfer, effectively inactivates deteriorative enzymes, better green colour retention. Microwave-blanched vegetables retain nutrients and provides better quality. Keywords: blanching, microwave, enzyme inactivation, ascorbic acid content, flavor, color and quality Introduction Blanching is an important thermal treatment carried out before several preservation processes like drying, canning, freezing, and for the most part determines the product quality (Xiao et al., 2014) [43] . The main objectives of blanching are: 1) to inactivate the enzymes (such as oxidase, POD and polyphenol oxidase, PPO) to prevent attainable deterioration reactions, off-flavours and undesirable changes in color (Lago and Norena, 2014) [23] ; 2) to reduce microbial load to prolong shelf-life (Afoakwa et al., 2013) [1] ; 3) to eliminate air within the intracellular space to increase the rate of heat and mass transfer and prevent oxidization (Ruiz-Ojeda and Penas, 2013); [36] and 4) to soften tissues to get product with specific texture (Xiao et al., 2014) [43] . Moreover, proper blanching will result in generation of superficial micro-cracks, which may enhance moisture transfer throughout drying method (Filho et al., 2016; Wang et al., 2017) [17, 41] . With numerous necessary roles, blanching is widely employed in the food processing industry. There are different types of blanching like wet blanching and dry blanching. Currently, hot water blanching is the most typical commercially adopted blanching methodology because it is easy and simple to implement (Mukherjee and Chattopadhyay, 2007) [28] . In typical hot water blanching, product is immersed in hot water (from 70 o to 100 o C) for many minutes. The blanched samples are drained and cooled before being sent to subsequent process operation. In general, after a certain amount of blanching time, blanching water has to be replenished because it becomes saturated with nutrients leached from the product. This step not solely consumes large amounts of water however additionally causes excessive energy consumption (Bingol et al., 2014) [6] . To preserve color of the product and to inactivate microbial activity, chemical reagents like sodium sulfite and sodium metabisulfite are usually added to the blanching water. This makes it tougher to treat the spent water from the blanching operation. Also, water-soluble nutrients, like vitamins, flavours, minerals, carbohydrates, sugars, and proteins, will leach out from the plant tissue into the blanching water. Commercial blanchers employed in the vegetable canning industry are relatively intensive in energy and water consumption. Energy utilization is affected by the instrumentation used and