But alternatively, pentanal and 2-methylpropanal content increased by 20 and 14% respectively. Alcohol compounds were identified as the second major group of volatiles. 1propanal was identified as a major alcohol compound and also the second most abundant volatile compound among the identified twenty-one compounds, and showed no significant effect on UV-A treatment. In addition, UV-A irradiation at 838 mJ/cm 2 significantly increased the availability of p-cymene (imparts typical milk flavor-aroma attributes) by 129%. Esters were identified as a third major volatile group with ethyl isobutyrate as the most abundant ester, and its concentration slightly (6%) decreased with UV treatment. In contrast, concentrations of two other identified esters; ethyl acetate and isopropyl acetate increased by 26 and 13% upon UV treatment. Among the acids present in WM, 3-methylbutanoic acid was found to be the most abundant one, which increased by 11% after UV-A irradiation at 838 mJ/cm 2 . In general, compared to control at doses 143, 279, 571, and 838 mJ/cm 2 the total volatiles content decreased by only 3, 3, 7, and 4% respectively. Although there is a slight difference in the total volatile composition of UV-A treated milk the difference seems to be lesser than that of thermally processed milk. Therefore, consumer acceptance may not be a significant challenge for UV-A-treated milk.