Mitigation of 3-Monochloro-1,2-propanediol Ester Formation by Radical Scavengers

摘要

The present study investigated the possible mechanism of free radical scavengers on mitigation of 3-monochloro-1,2-propanediol (3-MCPD) fatty acid ester formation in vegetable oils. The electron spin resonance investigation showed that the concentration of free radicals could be clearly decreased in 1,2-distearoyl-sn-glycerol (DSG) samples by all four antioxidants (L-ascorbyl palmitate, alpha-tocopherol, lipophilic tea polyphenols, and rosemary extract) at 120 degrees C for 20 min under a N-2 atmosphere. Moreover, the rosemary extract exhibited the highest inhibition efficiency. The Fourier transform infrared spectroscopy examination of DSG with alpha-tocopherol at 25 and 120 degrees C revealed that a-tocopherol could prevent the involvement of an ester carbonyl group of DSG in forming the cyclic acyloxonium free radical intermediate. Furthermore, the ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry analysis showed that a-tocopherol could suppress the formation of 3-MCPD di- and mono esters. Finally, the four antioxidants could decrease 3-MCPD esters in the palm oil during deodorization. Particularly, the rosemary extract also showed the highest efficiency in 3-MCPD ester mitigation.