Effect of long and medium chain length lipids upon aqueous solubility of alpha-tocopherol.

Abstract

AbstractThe efficiency by which α‐tocopherol is solubilized in vitro into mixed bile salt micelles containing different lipids was studied. Alterations in solubility due to addition to the incubation media of triglyceride, free fatty acid, monoglyceride, and lecithin of either long or medium chain length were examined. Results are expressed as a partition ratio between a micellar and an oil phase. The triglyceride of both long and medium chain length fatty acids greatly decreased the solubility of α‐tocopherol in bile salt solutions. When added singly, monoglyceride and lecithin of long chain length fatty acids increased the α‐tocopherol solubilized four‐ to fivefold; fatty acids of either chain length and medium chain monoglyceride when added singly had no significant effect upon the tocopherol solubilized. An additive effect was observed when a combination of long chain monoglyceride and lecithin was added. Addition of fatty acid to this combination, however, significantly decreased the α‐tocopherol solubility into the micellar phase. Although the solubility of α‐tocopherol was increased by all combinations of medium chain length polar lipids, except the fatty acid‐monoglyceride pair, the effect was three to seven times less than for the corresponding long chain mixture.