Chitosan based powder coating technique to enhance phytochemicals and shelf life quality of radish shreds

Minimally processed radish forms an important segment of the rapidly growing minimally processed industry worldwide. Radish shreds have a short shelf life thus necessitating the use of chemical additives. However, demand for natural preservatives in foods has increased. Chitosan is a natural antimicrobial biopolymer with a good film forming ability. Hence, it is used as an edible coating on whole and fresh cut fruits and vegetables. The present investigation explored powder coating technique using purified chitosan and chitosan lactate for shelf life extension of shredded radish. Macro perforated LDPE resealable pouches were used to pack the samples. Samples were stored at 10 degrees C for 10 d. Physicochemical characteristics, phytochemicals, antioxidant activity, respiration rate and color were analyzed periodically. The study also determined microbial load and sensory acceptability in the stored samples. Chitosan treated samples exhibited a lower degree of weight loss, respiration rate, titrable acidity, % soluble solids and higher content of phytochemicals, moisture, and pH compared with control samples. The treated samples also exhibited better sensory acceptability, lower exudate volume, lesser browning and lower microbial load compared to control. This indicated better potential marketability of the coated radish shreds. Chitosan powder coating could be used as an efficient technique for quality maintenance and shelf life extension of radish shreds with feasibility for large scale application. (C) 2013 Elsevier B.V. All rights reserved.