title: Designing excipient emulsions to increase nutraceutical bioavailability: emulsifier type influences curcumin stability and bioaccessibility by altering gastrointestinal fate.
abstract: The influence of emulsifier type on the ability of excipient emulsions to improve the solubility, stability, and bioaccessibility of powdered curcumin was examined. Oil-in-water emulsions prepared using three different emulsifiers (whey protein isolate, caseinate, or Tween 80) were mixed with curcumin powder and then incubated at either 30 °C (to simulate applications of salad dressings) or 100 °C (to simulate applications of cooking sauces). The transfer of curcumin into the excipient emulsions was appreciably higher for excipient emulsions held at 100 °C than those held at 30 °C, and was appreciably higher for surfactant-stabilized emulsions than protein-stabilized emulsions. For example, the amounts of curcumin transferred into emulsions held at 30 and 100 °C were 66 and 280 μg mL(-1) for Tween 80, but only 17 and 208 μg mL(-1) for caseinate. The total curcumin concentration in the digesta and mixed micelle phases collected after excipient emulsions were exposed to a simulated gastrointestinal tract (mouth, stomach, and small intestine) depended on emulsifier type. The total amount of curcumin within the digesta was higher for protein-stabilized emulsions than surfactant-stabilized ones, which was attributed to the ability of the proteins to protect curcumin from chemical degradation. For example, the digesta contained 204 μg mL(-1) curcumin for caseinate emulsions, but only 111 μg mL(-1) for Tween 80 emulsions. This study shows the potential of designing excipient emulsions to increase the oral bioavailability of curcumin for food and pharmaceutical applications.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, No. 235 Nanjing East Road, Nanchang 330047, Jiangxi, China. liuwei@ncu.edu.cn.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Zou
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Chengmei
authors.initials: C
authors.lastname: Liu
authors.forename: Hang
authors.initials: H
authors.lastname: Xiao
authors.forename: David Julian
authors.initials: DJ
authors.lastname: McClements
mesh_terms: D001682:Biological Availability; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003474:Curcumin / Q000737:chemistry / Q000378:metabolism*; D019587:Dietary Supplements / Q000032:analysis*; D004063:Digestion; D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry / Q000378:metabolism; D005079:Excipients / Q000737:chemistry* / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D010316:Particle Size; D011136:Polysorbates / Q000737:chemistry / Q000378:metabolism; D012995:Solubility; D000067816:Whey Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D002364:Caseins; D004655:Emulsions; D005079:Excipients; D011136:Polysorbates; D000067816:Whey Proteins; D003474:Curcumin