WM was treated at doses 0, 279, and 838 mJ/cm 2 and the thiobarbituric acid (TBARS) value for each treatment was calculated using the previously described method of with minor modifications. Briefly, 35.3mL of diluted (12% wt/vol) sample was placed in a water bath (30°C). Then, 2 mL of trichloroacetic acid solution (40% wt/vol) and 4 mL of ethanol solution (95% wt/vol) were added. The mixture was allowed to rest for 15 mins after shaking. The milk fat and proteins were then removed via filtration. The clarified filtrate was mixed with the TBA solution (0.1 mol/L, 1.0 mL), and the mixture was incubated in a water bath (60°C) for 60 minutes. At room temperature, the absorbance was measured at 538 nm.