Digestibility of Individual Fatty Acids in the Rat

Abstract

The digestibility of straight-chain saturated fatty acids from C₄ to C₂₂ and of mono-unsaturated fatty acids from C₁₈ to C₂₄ has been measured in the rat. Short-chain saturated fatty acids up to C₁₀ were completely digested. From C₁₀ to C₁₈ the digestibility decreased progressively and very small amounts of the C₁₈ and higher fatty acids were absorbed. The digestibilities of the mono-unsaturated fatty acids were approximately the same as those of saturated fatty acids with 6 less carbon atoms. These results do not support the concept of an inverse relationship between the digestibility of fatty acids and their melting points. Different methods of extracting fecal fat have been investigated and acidification of the feces with acetic acid to obtain fatty acids present as soaps appears to be preferable to acidification with hydrochloric or sulfuric acids.