Intestinal absorption and lipolysis of safflower oil and other unsaturated vegetable oils in rats

The intestinal lipolysis and absorption of safflower, corn, peanut, olive, cottonseed and soybean oils were studied in the rat. Oils and pancreatic lipase were injected into the rat jejunum and ileum (ligated in situ), and the amount of esterified fatty acids absorbed and free fatty acids present in the gut after 3 hours was determined. Safflower oil was absorbed significantly less than the other oils. There was no significant difference between the absorption rates of the other oils. When the oils were subjected to porcine pancreatic lipase in vitro, safflower oil also exhibited the lowest rate of hydrolysis. The rates of absorption and lipolysis of the oils could not be explained on the basis of deg re of saturation of constituent fatty acids. The low rate of hydrolysis of safflower oil represented the most plausible explanation of its low intestinal absorption