Abstract: The effects of hot air drying, infrared radiation and microwave radiation on the antioxidant activity of Maillard reaction products (MRPs) in oil-tea camellia seed oil (camellia oil) were investigated. The changes in the oxidation stability of camellia oil were investigated by measuring the contents of pyruvic aldehyde, glyoxal and 3-deoxyglucosone. The results showed that the production of pyruvic aldehyde and 3-deoxyglucosone increased with heating time, and the contents of pyruvic aldehyde and 3-deoxyglucosone in the camellia oils from the three drying methods under the highest intensity (150 ℃/120 min for infrared radiation and hot air, high power/20 min for microwave radiation) were in the decreasing order of infrared radiation > microwave radiation > hot air. The contents of glyoxal in the three camellia oils were approximately 7.0 μg/g. The MRPs extracted from the camellia oils showed antioxidant activity and were detected to contain pyruvic aldehyde and 3-deoxyosucide. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the MRPs obtained by the three drying methods followed the decreasing order: infrared radiation > microwave radiation > hot air. The results provide a theoretical basis for exploring the antioxidant mechanism of MRPs in camellia oil and for optimizing the processing of the oil.

Key words: oil-tea camellia seed oil, drying methods, Maillard reaction, antioxidant activity