Interactions of buttermilk with curcuminoids

• Published in: Food chemistry 2014-04, Vol.149, p.47-53
• Main Authors: Fu, Shishan, Shen, Zhiping, Ajlouni, Said, Ng, Ken, Sanguansri, Luz, Augustin, Mary Ann
• Format: Article
• Language: English
• Subjects: Animals; Binding; Biological and medical sciences; Buttermilk; Carrier; Cattle; Cultured Milk Products - chemistry; Curcuma - chemistry; Curcumin - analogs & derivatives; Curcumin - chemistry; Curcuminoids; Food toxicology; Functional food; Hydrogen-Ion Concentration; Kinetics; Medical sciences; Milk Proteins - chemistry; Plant Extracts - chemistry; Stability; Toxicology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2013.10.049

•Whole buttermilk is a potential carrier for curcuminoids into foods.•Curcuminoids are associated with the cream, milk serum and casein micelles in whole buttermilk.•The aqueous solubility and stability of curcuminoids is enhanced by buttermilk. The ability of buttermilk to carry and stabilise a preparation of curcuminoids was examined. The quenching of intrinsic protein fluorescence confirmed that the curcuminoids interacted with proteins in buttermilk. The Stern-Volmer quenching constant was ⩾9.4 × 103 M-1. The apparent binding constant of curcuminoids to whole buttermilk was ⩾2.2 × 104 M-1. Centrifugation of buttermilk (5% total solids, TS) – curcuminoid mixtures demonstrated that curcuminoids were partitioned into the cream (18.0%w/w, 0.64% TS), milk serum (73.3%w/w, 2.86% TS) and the casein-rich precipitate (6.76% w/w, 1.87% TS) fractions in the ratio of 1:3.7:3.5. The interaction of curcuminoids with components in the buttermilk improved its stability, as evidenced by the faster degradation of curcuminoids in phosphate buffer (pH=6.8) than in buttermilk. The ability of buttermilk to carry and stabilise curcuminoids has the potential to enable the delivery of these components into functional foods.