Postharvest quality and sensory evaluation of UV-treated tomato fruit

Pre-storage UV treatment has potential to control diseases in post-harvest crops. The objective of this work was to evaluate the quality of UV-treated tomato. Mature green tomato fruit (cv. Trust) were treated with a hormic dose of UV and stored at 13 degrees C for 21 days. Sensory quality parameters such as sugar content, total soluble solids, titratable acidity and pH were assessed at regular intervals. At the end of the storage period, on day 21, a random sample of fruit was kept at 20 degrees C for 72 hours simulating domestic handling. The latter fruit were used for sensory evaluation performed by a panel of graduate students and research assistants. Fruit of the same cultivar from a local market were used as reference. Over the storage period at 13 degrees C no significant difference was observed between UV-treated fruit compared with the control for total soluble solids. A similar trend was observed for sugar content except on day 21 where UV-treated fruit displayed a significant decrease. The titratable acidity, expressed as citric acid, of UV-treated fruit tended to be lower than the control fruit, with a significant difference observed only on day 7 after treatment; whereas there was a significant increase in pH of UV treated fruit from day 4 until the end of the storage period. Sensory evaluation indicated that the UV-treated fruit had a moderately better texture and taste than control fruit, although the general appearance and color were rated significantly poorer than those of the control fruit.