Orosensory factors in the ingestion of corn oil/sucrose mixtures by the rat

The experiments reported here were designed to study the orosensory factors contributing to the ingestion of sucrose/corn oil mixtures. When a flavor aversion was conditioned to the sucrose/corn oil mixture, the subsequent aversion to the mixture strongly generalized to the corn oil but very little to the sucrose. Rats conditioned with corn oil show a more profound aversion to the sucrose/corn oil mixture than rats conditioned with sucrose, indicating that the salient feature of the sucrose/corn oil mixture is the oil. Aversion to the sucrose/corn oil mixture does not generalize to a sucrose/mineral oil mixture, giving evidence that the textural aspects of the oil do not play a major role in its perception. This flavor aversion to the mixture is further illustrated in very short-term tests where postingestive factors are minimized, indicating a role for the gustatory system in the detection of the sucrose/corn oil mixture. Preliminary experiments are reported where conditioning tests were run with mixtures of sucrose and linoleic acid, one of the fatty acids that is possibly derived from a breakdown of the corn oil in the oral cavity by lingual lipase from von Ebner's Gland.