Digestibility of Cocoa Butter and Corn Oil and Their Influence on Fatty Acid Distribution in Rats

Abstract

The comparative bioavailability of cocoa butter (a predominantly saturated fat) and corn oil (a predominantly unsaturated fat) was determined in male Sprague-Dawley rats by analysis of total fecal lipids following ad libitum feeding of purified diets containing 5, 10 and 20% cocoa butter or corn oil for 2 wk. Fecal lipid elimination was significantly increased (P < 0.05) in each cocoa butter group when compared with the corresponding corn oil group, resulting in lower digestibility coefficients for cocoa butter (59–72%) than for corn oil (93–97%). Body weight gain and food intake data were similar among all treatment groups. Fecal fatty acid profiles in rats fed corn oil diets consisted primarily of 27–34% palmitic acid (16:0), 22–32% stearic acid (18:0) and 25–37% oleic acid (18:1). Palmitic, oleic and linoleic acids were also the primary fatty acids stored in epididymal fat tissue from corn oil—fed rats. In contrast, fecal fatty acids in animals fed cocoa butter diets consisted of 31–37% palmitic acid and 58–64% stearic acid; oleic acid was the major fatty acid stored in epididymal fat tissue. These results indicate that the decreased digestibility of cocoa butter is largely a result of its fatty acid composition. This reduced bioavailability of cocoa butter may be at least partially responsible for its previously described neutral effect on serum cholesterol.