Twenty-one major volatile compounds were identified (Fig. ) which accounts for >90% of the volatiles content, their retention time, and relative area percentile with respect to the UV-A dose delivered are presented in Table . Statistical analysis of total volatiles content between control and UV-A-treated samples indicated that there is a slight reduction in the volatile content. However, comparative analysis between treated samples at different dose levels (0 to 838 mJ/cm 2 ) showed no significant difference, p>0.05 The results indicated that there is a clear discrimination of clusters of volatiles among UV-A-treated and untreated WM samples. Based on their chemical nature, volatile compounds were further categorized into four major groups (aldehydes, esters, alcohols, and acids) and the effect of UV-A irradiation was illustrated in Table . Aldehydes were identified as a major volatile group in both untreated and UV-Atreated WM samples. The key aldehyde volatile compounds were Hexanal, Butanal, Pentanal, 2-methylpropanal, 2,4-Heptadienal, (E, E-), Octanal and 3-methylbutanal.