Influence of Lag Time Between Harvest and Pre-Cooling on Physiochemical Properties of Grapes (Thompson seedless) During Cold Storage

The on farm precooling of grapes with air velocity of 1.5 m/s and temperature of 2°C was carried out. The effect of cooling time delay on ‘a’ value of colour during storage period the grapes was increased from the initial value of-13.40 to-11.74 in immediately precooled and-14.06 to-8.12 precooled after 12 hand-12.62 to-6.38 non precooled during 40^th day of storage. Immediately precooled grapes shows the less PWL percentage of 4.57 and 23.10 in precooled after 12 h. The spoilage of grapes reaches 100% in control sample whereas immediately precooled grapes shows lowest spoilage percentage of 8.32%. The highest firmness value of 9.17 N was found immediately precooled and 6.62 N in precooled after 6 h. The highest total sugar content of 218.20 was foundduring 25^th day of storage in control decreased to 212.67 g/l in 40^th day of storage. The lowest pH value of 3.28 was non precooled control grapes. TSS of grapes after storage was increased to 10.41 in immediately precooled and 7.94°B in precooled after 12 h.