EFFECTS OF STEEPING CONDITIONS DURING WET-MILLING ON THE RETENTIONS OF TOCOPHEROLS AND TOCOTRIENOLS IN CORN

Vitamin E is a natural antioxidant that plays significant roles in foo d preservation and disease prevention. There are eight naturally occur ring vitamin E isomers (tocols): alpha-, beta-, gamma-, and delta-toco pherols and alpha-, beta-, gamma-, and delta-tocotrienols. Corn oil is a major source of vitamin E. Most of the corn oil produced in the Uni ted States is a co-product of corn wet-milling. There is limited knowl edge about the effects of corn wet-milling on the retention of these v itamin E isomers. A high-performance liquid chromatography method was developed for simultaneous determinations of tocols in steeped corn sa mples. Effects of steeping conditions (steeping time and SO2 concentra tion) on retention of tocols in corn were investigated, alpha-Tocopher ol, gamma-tocopherol, alpha-tocotrienol, and gamma-tocotrienol are the predominant vitamin E isomers in the corn variety used in the study. Steeping conditions had little effect on the concentration of alpha-to copherol and alpha-tocotrienol. However, a higher concentration of SO2 and a shorter steeping time gave a slightly higher gamma-tocotrienol content and lower gamma-tocopherol content. Corn kernels steeped in a vitamin C solution had a much higher concentration of the tocols than those steeped in SO2 solution.