Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/1998
Publication Date: N/A
Interpretive Summary: When stored at low temperatures, tomatoes are susceptible to chilling injury and subsequent decay, particularly at the mature-green stage of maturity. Florida, which is the largest producer state of tomatoes in the U.S., ships almost its entire production mature green. We have shown in previous research that various prestorage heat treatments can reduce chilling injury of tomatoes and other fruits and vegetables. The present study is an attempt to enhance the effectiveness of the short- term heat treatments reported in our earlier work, which permit the successful storage of mature-green tomatoes at chilling temperatures. In addition, we monitored the effects of various water heat treatments and storage temperatures on tomato fruit quality at the red-ripe stage. We found that heat treatments in the range of 39 to 45?C allowed for successful storage at low temperatures. Heat-treated tomatoes appeared to ripen normally and the changes in various quality parameters did not seem to be detrimental to overall quality. A pretransit water heat treatment could allow Florida-produced tomatoes to be surfaced-shipped to emerging markets in the Pacific basin.
Technical Abstract: Mature-green tomato fruit (Lycopersicon esculentum Mill. cv. Sunbeam) were treated in water for 1 h at 27 (ambient), 39, 42, 45, or 48?C, and then either ripened at 20?C (nonchilled) or stored at 2?C (chilled) for 14 days before ripening at 20?C. Treatment at 42?C reduced decay 60% whereas the other water temperatures were less effective. Red color development was enhanced by heat treatment, and inhibited by chilling. At red ripe, fruit were firmer as a result of storage at the chilling temperature while heat treatment had no effect on firmness. With the exception of the 45?C treatment, Chilled as well as nonchilled fruit previously treated at 39, 42, or 45?C were preferred in terms of taste and texture in informal taste tests over fruit treated at 27 or 48?C. Storage at 2?C led to an increase in electrolyte leakage, particularly in the 48?C treated fruit. Of the 15 flavor volatiles analyzed, the levels of 5 were decreased and 2 were increased with increasing temperature of heat treatment. Storage at the chilling temperature reduced the levels of 5 flavor volatiles. Heat treatments decreased sterols in the steryl ester fraction, several sterols in the free sterol, steryl glycoside, and acylated steryl glycoside fractions. Prestorage heat treatments, with the possible exception of the 48?C temperature, can reduce decay with only minimal adverse effects on tomato fruit quality.