Role of unsaponifiable fraction on the preference for beef tallow in C57Black/6 mice.

We examined the contribution of unsaponifiable fraction, a model for minor substances in food fat, on the preference for beef tallow in C57Black/6NCrj mice. First, we tested the difference in preference among three kinds of beef tallow in mice by a two-bottle choice test. The beef tallow samples were preferred in the order 'premium' food-use, food-use, and chemical grades. The amount of unsaponifiable fraction was the highest in the premium and the lowest in the chemical-grade beef tallow sample. Fatty acid and triacylglycerol profiles, however, were similar in the three samples. Subsequently, we examined the effects and role of unsaponifiable fraction in the preference for triacylglycerol. Unsaponifiable fraction prepared from premium beef tallow sample alone did not affect the preference in mice, but a preference was observed when triolein and unsaponifiable fraction coexisted. These results indicated that the unsaponifiable fraction in beef tallow contributed to the preference in mice. In addition, it was suggested that the unsaponifiable fraction acted as an enhancer in the preference for triacylglycerol in C57Black/6NCrj mice.