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Onion and ginger are rich sources of bioactive compounds which are lost during conventional drying process. The present study was designed to optimize the novel Microwave Assisted Drying and Extraction technique (MADE) for simultaneous drying and extraction/recovery of bioactive compounds from model food products. The time required for drying of samples was 11 (onion) and 16 (ginger) minutes with recovery yield of 87% (onion) and 85% (ginger). The drying time was reduced to 100 times compared to hot air drying and moisture ratio of dried samples was best described by Midilli model. The diffusivities of onion and ginger slices were 1.27 e(−11) and 1.43 e(−11) m(2)/s, respectively. Moreover, microwave-based extraction was compared with conventional one. The results of antioxidant activity and total phenolic contents of condensates obtained through MADE were higher compared to conventional method. In short, MADE exhibited better yield of extraction and drying properties compared to conventional methods.

There is a continuous need for thin edible coatings with excellent barrier properties, which has resulted in the quest for new coating methods. Electrospraying is a novel coating technique that is known to yield fine droplets of size down to 20 μm and even smaller ones, giving the potential of ultra-thin and uniform coatings. In this review, various process parameters are discussed that influence the coating quality and efficiency for electrospraying. The droplet size during the spraying process is a function of operational parameters and liquid properties. Successful deposition of thin films has been reported for model (conductive and non-conductive) surfaces (aluminium, Parafilm and various membranes) as well as food surfaces (apple and candies). This review article is an attempt to summarize valuable information about process optimization for food applications. The existing scaling relations are presented here relating various process and product-related parameters.