Influence of Lag Time Between Harvest and Pre-Cooling on Physiochemical Properties of Leafy Lettuce (Lactuca sativa) During Storage

The on farm precooling of lettuce with air velocity of 1.5 m/s and temperature of 4°C was carried out. The effect of cooling time delay on physiological weight loss percentage was high as 20.47% during 20^th day of storage in non-precooled control and less in immediately precooled lettuce as 5.20%. The spoilage reaches 98.6% in control sample whereas only 13.7% in precooled after 3 h. The ‘a’ value of colour was increased from the initial value of-34.65 to-19.29 in immediately precooled, -33.20 to-9.39 in precooled after 3 h and-33.39 to-14.81 in nonprecooled control during 20^th day of storage. The reduction in chlorophyll content is less in immediately precooled lettuce while compared to all other treatments. During 20^th day of storage the total phenol content in immediately precooled was found to be 2.52, and in 2.26 mg/g precooled after 6 h after harvest.