ORIGINAL PAPER Influence of Postharvest UV-C Hormesis on the Bioactive Components of Tomato during Post-treatment Handling S. L. Jagadeesh & M. T. Charles & Y. Gariepy & B. Goyette & G. S. V . Raghavan & C. Vigneault Received: 8 April 2009 / Accepted: 28 August 2009 / Published online: 16 September 2009 # Her Majesty the Queen in Right of Canada 2009 Abstract Mature green tomato fruit exposed to a pre- determined 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. Ascor- bic acid and total phenolic contents were higher in the UV- treated 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. Keywords Antioxidant . Ascorbic acid . Bioactive . UV-C hormesis . Lycopene . Tomato . Total phenolic . Trolox equivalent Introduction The beneficial effects of fresh fruit and vegetable on human health, also termed as their bioactive potential, have been associated with various classes of compounds with antiox- idant properties, a concept that has gained in popularity over the recent years. The consumption of fruit and vegetable is reported to contribute to about 50% of the total recommended daily intake of antioxidants for humans (ca. 3,000–3,600 μmol Trolox equivalent, TEAC) (Prior and Cao 2000). Important contributors to the antioxidant properties of fresh produce are phenolic compounds, pig- ments, and vitamins. Their bioactivity is typified by their antimutagenic and anticancer properties, and their professed ability to prevent cardiovascular and age-related diseases (Dillard and German 2000). The consumption of fruit and vegetable is expected to increase over the coming years due to the population aging, and there is a need to develop technologies that can ensure the delivery of high-quality products containing high levels of desired bioactive com- pounds (Cisneros-Zevallos 2003). Enhancing the health benefits of fresh produce could therefore add value and create new opportunities for growers and processors by enabling them to earn profitable shares in health-oriented markets. Tomato fruit (Lycopersicon esculentum Mill.) is among the most popularly consumed fruit in the world and as such could be considered as an important source of dietary antioxidants (Lenucci et al. 2006). The main antioxidants in tomatoes are the carotenoid pigments, ascorbic acid, and S. L. Jagadeesh : Y. Gariepy : G. S. V. Raghavan Department of Bioresource Engineering, McGill University, Montréal, Canada M. T. Charles (*) : B. Goyette : C. Vigneault Horticulture Research and Development Centre, Agriculture and Agri-Food Canada, St-Jean-sur-Richelieu, Quebec, Canada e-mail: marietherese.charles@agr.gc.ca Present Address: S. L. Jagadeesh K.R.C. College of Horticulture, Arabhavi, Karnataka, India Food Bioprocess Technol (2011) 4:1463–1472 DOI 10.1007/s11947-009-0259-y