TOMATO FLAVOR AND AROMA QUALITY AS AFFECTED BY A SHORT ANOXIA TREATMENT

Abstract

Exposing fruit and vegetables to anoxia (N 2 ) after harvest has many beneficial effects, such as reducing respiration rate, inhibiting ethylene production and action, delaying ripening and reducing the incidence of some physiological disorders. The purpose of this work was to compare the sensory quality of tomatoes treated for 24 h under anoxia (99% N 2 ) with that of control fruit kept in air. Fruit were harvested at pink stage and were held for 12 days at 20°C or at 12°C for 10 d plus 2 days at 20°C. Human-sensory parameters (organoleptic analysis by a trained panel) and aroma volatiles (headspace SPME-GC-MS analysis) were measured at the end of storage and marketing simulation. Anoxia-treated fruit that were held at 20°C for 12 days had organoleptic qualities similar to those of untreated fruit that were held at 12°C for 10 d plus 2 d at 20°C, and the trained panel preferred these two treatments. Of the 11 volatiles assayed, hexanal (grassy odor), 2-isobutythiazole (tomato-like smell) and benzaldehyde (sweet odor) were higher in N 2 -treated fruits held at 20°C than in controls, while 2+3-methyl butanol (unpleasant smell) and ethanol (fermented odor) were slightly higher in control. In anoxia-treated fruit held at 12°C for 10 d, the amount of 2-isobutythiazole was lower than in control fruit, while 2+3-methyl butanol was slightly higher. In conclusion, the taste and smell (sensory quality) of pink harvested tomatoes could be sustained for about two weeks at ambient temperature under a short anoxia treatment. This non-chemical and inexpensive treatment deserves further development and application, especially under commercial distribution systems where refrigeration is inadequate.