Optimization of Modelling of storage conditions in forced Air cooling of SAPOTA (MANILKARAZAPOTA) using Response Surface Methodology

Abstract

Field heat can cause rapid deterioration of horticultural crops and therefore it is desirable to remove this heat as quickly as possible after harvesting, and the faster the deteriorative processes are retarded. Thegoal of the present study was to apply Response surface methodology (RSM) to search for the best conditions of Forced Air-Cooling system for extending the shelf life of Sapota.The parameters which affect the cooling rate the most were identified as Cooling Medium temperature (4 ̊C, 8 ̊C and 25 ̊C), Fruit Size (0.00454 m, 0.00567m and 0.00662 m) andCooling Air Velocity (0.5 m/s, 1.5 m/s and 2.5 m/s) at which the produce is stored. Based on general factorial design of RSM shelf life (number of days) as a response, 27 (33) treatments were conducted.Optimum storage conditions for maximizing the shelf life wereidentified as Cooling Medium temperature (4 ̊C), Fruit Size (40-50 mm) and Cooling Air Velocity (2.5 m/s). Under this optimum condition, the predicted shelf life of the stored Sapota and the experimental results gave close values of less than 1.03 %. The number of days of shelf life extended for Sapota is 28days. Physio-chemical properties and microbial quality of stored Sapota was also evaluated. Percentage Loss in Weight was found to be maximum for control sample (13 %) whereas minimum for the cooled sample (0.04-0.123%). TSSincreased about 5%-7% for controlbut whereas for cooled sapota it was not more than 1-2%.