Effect of Temperatures and Exposure Times of Hot Water Treatment on Color Development and Quality of Cherry Tomato Fruits

Abstract

Hot water treatment (HWT) at a range of temperatures from 35 to 65°C and of exposure times from 10s to 210min were applied to cherry tomato fruits (Lycopersicon esculentum cv. Coco) at turning stage. During storage at 20°C surface color was estimated by a/b ratio from CIELAB (L, a, b) color space coordinates and the delays in color developments of treated fruits were quantitatively expressed by a newly defined color-delay index. We were successful in determining the conditions of HWT where the color development was delayed without the occurrence of any damage. Those conditions ranged in restricted combination of temperature and exposure time and formed an effective HWT region. At red-ripe stage, sugar content and firmness of cherry tomato fruits treated in such effective HWT region were similar to those of control fruits. The determination of effective temperature and time conditions of HWT in the present study should be valuable in the application of HWT technique to quality management of fresh cherry tomato fruits.