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ARS Home » Midwest Area » Madison, Wisconsin » Cereal Crops Research » Research » Publications at this Location » Publication #42873

Title: OAT TOCOLS: CONCENTRATION AND STABILITY IN OAT PRODUCTS AND DISTRIBUTION WITHIN THE KERNEL

Author
item Peterson, David

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Oats and other cereal grains are important sources of vitamin E, one of the essential vitamins. Although we have good data on the concentration of vitamin E in the grain, we do not know the effects of processing for oatmeal and other oat products or of storage time and conditions. This experiment showed that heating, which is the first step in oat processing, caused the vitamin E to degrade over a period of several months of storage at room temperatures. The degradation was faster in envelopes than in jars, indicating that exposure to air hastened the degradation process. The impact of this research will be on manufacturers of oat products, who, if they choose to indicate vitamin E amount on the label, should allow for the expected decrease during anticipated shelf-life. Further analyses of the products under actual packaging and storage conditions will be needed.

Technical Abstract: To determine the stability of tocols (vitamin E) in oat products under various storage conditions, several oat products were stored in jars at -24C or in jars or envelopes at room temperature for up to 7 months. At approximately monthly intervals, products were ground and tocols were extracted with methanol and analyzed by HPLC. Tocols were stable for 7 months in all products in jars in the freezer. At room temperature, all tocols degraded in all processed products, but were stable in undried groats. Tocols degraded faster in envelopes that in jars at room temperature, indicating that air may be involved in the degradation process. As a percentage of total tocols, alpha-tocopherol, alpha- tocotrienol, and delta-tocotrienol tended to decrease, and beta- tocopherol, beta-tocotrienol, and gamma-tocopherol tended to increase with storage time, indicating differential stabilities. Analysis of hand-dissected fractions indicated that the germ was the location for most of the alpha- and gamma-tocopherol. Tocotrienols were concentrated in the endosperm, and absent from the germ.