Carotenoids in biological emulsions: solubility, surface-to-core distribution, and release from lipid droplets

作者：Patrick Borel, Pascal Grolier, Martine Armand, Anne Partier, Huguette Lafont, Denis Lairon, Véronique Azaı̈s-Braesco · 发表于：Journal of Lipid Research · 年份：1996 · DOI：10.1016/s0022-2275(20)37613-6 · 被引用次数：356 · 研究领域：Antioxidant Activity and Oxidative Stress、Algal biology and biofuel production、Fatty Acid Research and Health

Data on the physico-chemical properties of carotenoids in biological emulsions are essential to our knowledge of carotenoid metabolism. Therefore, we determined the behavior of carotenoids in phospholipid-stabilized triglyceride emulsions, a model for biological emulsions such as dietary emulsions, triglyceride-rich lipoproteins, and intracellular storage droplets. The solubility of beta-carotene (a model for apolar carotenoids, carotenes) in pure bulk triglycerides (0.112 to 0.141 wt % according to triglycerides) was significantly higher than zeaxanthin (a model for polar carotenoids, xanthophylls) (0.022 to 0.088 wt %). The solubility of both carotenoids increased when the chain-length of the triglycerides' fatty acids decreased. The amount of zeaxanthin associated with lipid droplet dramatically increased in phospholipid-triglyceride droplets as compared to the pure corresponding triglyceride droplets, whereas the amount of beta-carotene associated with lipid droplets increased only slightly beta-Carotene distributed almost exclusively in the core of triolein-lecithin-carotenoid droplets, while zeaxanthin distributed preferentially at the droplet's surface. A significant percentage (8.3%) of zeaxanthin was spontaneously transferred from lipid droplets to aqueous phase and the remaining part was transferred during triglyceride hydrolysis catalysed by pancreatic lipase, while beta-carotene absolutely required triglyceride lipolysis to be transferred to the aqueous phase. Our...