Influence of UV-A irradiation on the selected nutrient composition and volatile profiling of whole milk: Safety and quality evaluation

Abstract

Aflatoxin (AF), a mycotoxin produced by several genera of fungi, is an important concern in milk-based products due to its toxicity and health consequences. The present study evaluates whether UV-A irradiation can preserve the composition of whole milk (WM) while degradaing these toxins. In addition, this study also investigates the expression of p53 proteins which can be correlated with carcinogenocity. UV-A irradiation experiments were conducted using a near collimated beam system operating at 365 nm. AFs at known concentrations were spiked in WM and irradiated at quantifiable UV doses based on the average volumetric intensity. The impact of ultraviolet light (UV-A) irradiation on volatile compounds, certain amino acids, and oxidative products were evaluated. No significant reduction in amino acids was observed except tryptophan (p < 0.05). Therefore, tryptophan particularly gets degraded under UV and generates OH− radical. At 838 mJ/cm2 no significant lipid peroxidation was observed, p < 0.05. The volatile profiling showed that alcohols, the key contributor of oxidized flavor was not significantly affected by the UV-A irradiation. As the overall volatile composition was comparable between the untreated and UV-A irradiated WM there may not be an adverse impact on the sensory attributes. Western blotting was used to assess the effect of UV-A irradiated WM on protein expression in HepG2 cells. Because the targeted gene p53 was not considerably altered, we can affirm that UV-A irradiated WM may be safe and not cytotoxic. Herein, the substantial breakdown of AF in WM by UV-A as well as no accumulation of toxic components from protein, lipid, and FAA degradation was observed. This study conclusively proves the performance of the UV-A LED system in degrading AF in WM below the levels recommended by Food and Drug Administration without compromising the product's quality or safety.