Low-dose UV-C irradiation reduces the microbial population and preserves antioxidant levels in peeled garlic (Allium sativum L.) during storage

Ultraviolet (UV) irradiation is used to control postharvest diseases and delays deterioration related to the ripening of fresh produce. Here, we investigated the effect of UV-C on the quality and functional properties of peeled garlic during storage. UV-C-treated garlic cloves remained firmer than the controls during storage. After 15 days at room temperature, hue values were lower for UV-C-treated garlic cloves than for the controls, which developed a yellow coloration. We also found that aerobic microbial populations were lower in 2 kJ m(-2) UV-C-treated garlic than in untreated controls when stored at room temperature for 15 days (6.78 log CFU vs. 6.10 log CFU); however, treated garlic stored at 0 degrees C showed a one-log reduction in the microbial population after 30 days. In addition, total polyphenol and flavonoid content was high in 2 kJ m(-2) UV-C-treated garlic after 15 days storage at 0 degrees C and total flavonoid content was significantly higher in UV-treated cloves than in the control cloves up to 10 days storage at room temperature. Apigenin and quercetin levels also increased in UV-C treated garlic under cold storage. Thus, UV-C irradiation could be used to reduce the microbial population and maintain or increase antioxidant levels in peeled garlic cloves. (C) 2014 Published by Elsevier B.V.