VOLATILE COMPOUNDS PRODUCED DURING DEODORIZATION OF SOYBEAN OIL AND THEIR FLAVOR SIGNIFICANCE

Freshly deodorized soybean oil has a characteristic nutty flavor but o ften yields no detectable headspace volatiles. The cause of this flavo r was investigated by deodorizing soybean oil in an apparatus with a d ouble cold trap that allowed the volatile compounds formed from the in itial decomposition of hydroperoxides to be collected separately from those produced during the normal deodorization process. The chief vola tile components from the normal deodorization process were hydrocarbon s, which contributed little to no odor to the oil. The compounds with the greatest odor were carbonyls, especially heptanal and cis-4-hepten al. Although these components should accumulate at some steady-stale c oncentration in an oil during its deodorization, none seemed to accoun t for the flavor of the deodorized oil. By using a particle detector, it was shown that small particles could be generated in the human mout h that could provide a mechanism to bring oil with nonvolatile flavor components into contact with the olfactory organ. Attempts to separate possible nonvolatile flavors in deodorized oil from triacylglycerides by chromatography on alumina or reaction with 2,4-dinitrophenyl hydra zine were unsuccessful. Possibly, the favor is caused by the glycerol esters themselves.