Bhatia, SurekhaAmrit Preet Kaur2019-05-012019-05-012019http://krishikosh.egranth.ac.in/handle/1/5810101473Effect of post harvest treatments by edible coatings viz. pectin and carboxymethyl cellulose on physiological and biochemical parameters in relation to activities of antioxidative enzymes were investigated in radish and carrot. Carrot of variety Punjab Carrot Red and radish of variety Punjab Safed Mooli 2 were harvested, washed, surface dried and coated with pectin (0.5 and 1%) and CMC (0.5 and 1%). Coated as well as uncoated carrot and radish were placed in open trays, jute bags and perforated bags and were stored under ambient and refrigerated conditions. Irrespective of coatings, packaging material and environmental conditions, a gradual decline in weight, colour, texture and carotenoid content with simultaneous enhancement in total soluble solids, total antioxidant activity and ascorbic acid content was found with increase in storage period in both radish and carrot whereas titrable acidity and total phenolics first increased reaching to its maximum and declined thereafter. Irrespective of the coatings and packagings, an enhancement in the activity of antioxidative enzymes was observed under ambient as well as refrigerated conditions. The activities of CAT and SOD first increased followed by a decline under both storage conditions in carrot whereas, in radish, the CAT activity increased continuously under both conditions but the activity of SOD first increased and then decreased in ambient conditions with a continuous increase under refrigerated conditions. In both carrot and radish, the activities of GR and POX first increased to highest and then decreased whereas the activities of DHAR and MDHAR increased continuously during storage under both environmental conditions. Changes in physiological and biochemical quality parameters during storage were high under ambient conditions as compared to refrigerated conditions. Coating and packaging of carrot and radish slowed down the changes in biochemical and physiological quality parameters and enhanced the rate of increase in activities of antioxidative enzymes as compared to uncoated and unpacked samples under both the storage conditions. Effectiveness of different coatings in enhancing the activity of antioxidative enzymes and maintaining the biochemical quality parameters was in order of 0.5% pectin> 0.5% CMC> 1% pectin> 1% CMC. However, coating of carrot and radish with 1% pectin and 1% CMC were not much effective. Among the packaging materials, jute bags packed samples exhibited higher maintenance in the quality parameters as well as higher activities of antioxidative enzymes as compared to perforated bags and open trays. Among all the treatments, samples coated with 0.5% pectin and packed in jute bags maintained the quality parameters to greater extent possibly by reducing the oxidative stress and can be used to enhance the shelf life of carrot and radish.ennullThesis