UV-C irradiation of tomato and its effects on color and pigments.
Maharaj, R., Arul, J., and Nadeau, P. (2010). "UV-C irradiation of tomato and its effects on color and pigments.", Advances in Environmental Biology, 4(2), pp. 308-315.
The effect of hormic dose (UV-3.7 kJ m⁻²) of ultraviolet radiation in delaying the senescence of tomato was investigated. Mature-green tomato fruits (var. Capello) were irradiated with doses of ultraviolet light (UVC, 254 nm) corresponding to 0 (control), UV-3.7 kJ m⁻² (hormic dose) and UV-24.4 kJ m⁻² (hyper dose) and were stored at 16°C, under high relative humidity for a period of 28-35 days. Attributes of senescence such as color, pigments (chlorophyll, lycopene, total carotenoids) and total protein were monitored periodically throughout the storage period. The development of color and lycopene as well as the decline in chlorophyll were significantly (p≤0.001), retarded during storage in response to the treatment with both the hormic and hyper doses. However the hyper dose impaired ripening and caused abnormal browning, manifested as sunscalding of the fruit’s surface. One possible mode of UV action is attributable to the significantly higher levels of total carotenoids found in irradiated fruits compared to controls indicative of a phytochemical antioxidant defense mechanism.