UPLC-MS/MS profiling of photodegradation of aflatoxin B1 in chili peppers

In this study, photodegradation products of aflatoxin B1 in an acetonitrile-water mixture formed during the UV irradiation were profiled using UPLC-MS/MS. Structures and photodegradation pathways of ten UV-reaction products of aflatoxin B1 were elucidated. UPLC-MS/MS conditions for the analysis of aflatoxin B1 and its photodegradation products were also optimized and used to monitor the kinetics of degradation of aflatoxin B₁ in red chili paste during UV and sunlight irradiation. Aflatoxin B1 in the acetonitrile-water mixture and chili pepper paste was reduced to 30 to 58% of its original concentration on exposure to UV and sunlight for 4 h. The reduction of aflatoxin B1 in chili pepper during sunlight exposure was significantly less than that in UV exposure, which could be attributed to the presence of photosensitive phytochemicals like carotenoids in chili pepper extracts. Most of the degraded products had modifications in the structural characteristics viz.; double bond in the terminal furan ring, lactone moiety, and cyclopentenone ring in aflatoxin B1, which indicated the possible reduction in toxicity of aflatoxin-contaminated chili pepper with UV and sunlight irradiation.

The online version contains supplementary material available at 10.1007/s13197-025-06253-8.