Flavor of fresh market tomato (Lycopersicon esculentum Mill.) as influenced by harvest maturity and storage temperature

The effects of harvest maturity and storage temperature on fresh tomato (Lycopersicon esculentum Mill.) chemical composition and sensory quality at ripe stage were investigated. Tomatoes from seven commercial cultivars harvested at green stage were exposed to exogenous ethylene (100 μL/L) to accelerate the onset of ripening for 1 to 7 days until they attained breaker stage (<10% red color). There was a strong relationship (r2 = 0.84) between green-tomato maturity at harvest and ethylene exposure time to attain breaker stage. Immature-green (M1) tomatoes had to be treated with ethylene for >3 days compared to mature-green (M4) tomatoes which were treated for 1 day. Ripe tomato color parameters (L* and a* values) consistently increased with increasing ethylene requirement, indicating development of less intense-red coloration with immature-harvested fruit.; Untrained sensory panelists found significant differences in ripe tomato flavor between fruits exposed to ethylene for 1, 3 or 5 days to attain breaker stage. Descriptive sensory panelists determined that at ripe stage green-harvested tomatoes exposed to <3 days of ethylene treatment were comparable in ripe aroma, sweetness and tomato flavor to tomatoes harvested at light-red stage. In contrast, tomatoes that reached breaker stage after 3 days of ethylene treatment were rated highest in sourness and green/grassy flavor, and lowest in ripe aroma, sweetness and tomato flavor. Ripe tomatoes with inferior sensory qualities showed significant changes in several aroma volatile compounds and chemical composition parameters. An ethylene exposure threshold of 3 days could be immediately utilized commercially as a non-destructive means for segregating immature-green from mature-green tomatoes, thus ensuring consistently high-flavor tomatoes.; Ripe tomatoes stored at 20°C for 12 days were rated significantly higher for ripe aroma, tomato flavor and sweetness compared to those stored at 10° or 5°C. High temperature pre-treatments (38°C for 2 days) were not effective in alleviating flavor changes induced during storage at 5°C for 7 days.; The electronic nose sensor array successfully classified intact green tomatoes into immature and mature stages, and distinguished between tomatoes harvested at different ripeness stages or stored at various temperatures below 20°C. With increased detection speeds, electronic noses have potential for screening green tomatoes in commercial operations.