Influence of Postharvest UV-C Hormesis on the Bioactive Components of Tomato during Post-treatment Handling

Abstract

Mature green tomato fruit exposed to a predetermined hormetic dose of UV-C (3.7 kJ/m 2 ) and untreated fruit (control) were stored at 13°C and 95% relative humidity. After 10, 20, and 30 days of storage, fruits were randomly sampled and transferred to room temperature (23°C) for 7 and 14 days to allow ripening. Edible pericarp was excised from the equatorial region for subsequent analyses of the antioxidant components. Ascorbic acid and total phenolic contents were higher in the UVtreated tomatoes, but UV treatment significantly reduced the lycopene content of the tomatoes. The UV treatment did not affect significantly the antioxidant activity of the hydrophilic extract, expressed as Trolox equivalent. Both storage and ripening period were found to affect positively all the bioactive components of tomato evaluated in this study. The results suggest the possible existence of a window of opportunity for the development of practices based on storage temperature and duration to preserve the beneficial effects expected from UV-C hormesis and to circumvent its negative impact on lycopene synthesis.

The influence of hot air treatment and UV irradiation on the quality of two tomato varieties after storage

“…This significant difference in color is in accordance with poor appearance scores of these samples, which were given by the panelists because of partial green discoloration of fruits. Significantly lower red tone could be explained by lower accumulation of lycopene in UV treated fruits, because increase of a* value is directly related to lycopene synthesis (Arias et al, 2000;Jagadeesh et al, 2011). Lower chroma and higher hue angle values of UV irradiated mature green tomato fruits were also observed by Liu et al (2012) after storage at 20 C. In study of Soto-Zamora et al (2005), carotenoid and lycopene content were significantly correlated with hue angle values.…”

“…UV-C is generally harmful but can produce several beneficial effects on horticultural crops at low doses, a phenomenon known as hormesis (the stimulation of beneficial responses by low levels of stressors which are otherwise detrimental) (Maharaj et al, 1999;Barka, Kalantari, Makhlouf, & Arul, 2000). Exposure of horticultural crops to UV-C light has been considered as an alternative to chemical fungicides for the control of postharvest diseases, since it is both harmful to spoilage organisms (bacteria and moulds) and can activate disease resistance in plants (Maharaj et al, 1999;Jagadeesh et al, 2011;Bravo et al, 2012). UV irradiation of tomatoes was found to induce reduction of cell wall-degrading enzymes activity and higher resistant of fruits to penetration, indicating that irradiation retards tomato fruits softening (Barka et al, 2000).…”

“…UV-C and UV-B treatment of ripe tomatoes during postharvest handling was successfully combined with modified atmosphere (MA) storage, resulting in a product that was minimally changed during storage and had higher antioxidant capacity (Vunnam et al, 2014). Moreover, UV-C radiation was shown to increase ascorbic acid, lycopene, and total phenolic content in tomato fruit (Jagadeesh et al, 2011;Liu, Zabaras, Bennett, Aguas, & Woonton, 2009;Bravo et al, 2012).…”

The Influence of Retailing Packaging on Tomato Quality

“…The amount of the various nutrients in tomato fruits will depend on several factors such as cultivar, harvesting time, postharvest handling procedures including packaging and storage. However, of these factors, postharvest handling seems to be the most important [19]. Therefore, controlling or maintaining the pre-harvest quality of fresh produce is very vital in providing fresh produce of good quality to the consumers.…”

The Influence of Pre‐ and Postharvest Environmental Stress on Fruit Bioactives

“…Jagadeesh et al (2011) exposed mature green tomato fruit to a dose of UV-C (3.7 kJ/m 2 ) and compared the levels of bioactive in UV-C treated fruits with untreated fruits. Fruit was stored at 13 • C and 95% relative humidity for 10, 20, and 30 days and transferred to room temperature (23 • C) to allow ripening.…”