The effect of deodorization prior to hydrogenation on the development of hydrogenation odor in fats

Summary The direct precursors of hydrogenation odor are removed by steam deodorization. The primary precursors remain in the oil since the reversion of deodorized oil by autoxidation in the presence of light and heat forms certain compounds which again give rise to hydrogenation odor. Thus, in order to prevent the formation of hydrogenation odor, the deodorized oil must be protected from the effects of heat, light, and autoxidation, and hydrogenated in a unit which is free of residues from previous hydrogenations that were not carried out in a manner to prevent the formation of odor. The best results were obtained with palladium catalyst at temperatures below 90°C. The high flavor stability of hydrogenated soybean oil which was deodorized and protected from autoxidation prior to hydrogenation indicates that certain compounds responsible for hydrogenation flavor may also be involved in flavor reversion.