title: Buffering colour fluctuation of purple sweet potato anthocyanins to acidity variation by surfactants.
abstract: Anthocyanins are intriguing natural pigments with beneficial bioactivities and their colour is extremely susceptible to acidity variation. Minimisation of colour fluctuation is essential to maintain quality consistency in food industry. A new strategy employing surfactants to mimic encapsulation was attempted with typical anionic, cationic and nonionic surfactants and proved effective although the traditional copigmentation method was inactive. The exceptional colour fluctuation buffering effect of anionic surfactants especially sodium dodecyl sulphate (SDS) was revealed and then carefully analysed by colorimetric and spectroscopic methods. The outstanding activity of SDS presumably resulted from effective shielding of anthocyanins from external acidity through strong interaction with the positively charged flavylium cations owing to its anionic nature. These results suggest SDS is a valuable additive for buffering colour fluctuation of anthocyanins. The strategy of surfactant will be useful for buffering colour fluctuation of natural colourants.
authors.affiliation: Department of Food Science and Nutrition, Fuli Institute of Food Science, Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. Electronic address: songbailiu@zju.edu.cn.
authors.forename: Songbai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Food Science and Nutrition, Fuli Institute of Food Science, Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
authors.forename: Yuanqing
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Food Science Department, Cook College, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, USA.
authors.forename: Si
authors.initials: S
authors.lastname: Nian
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D027723:Ipomoea batatas / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D013501:Surface-Active Agents
chemical_list: D000872:Anthocyanins; D010936:Plant Extracts; D013501:Surface-Active Agents
keywords: Anthocyanin; Colour fluctuation; Colour stability; Purple sweet potato; Sodium dodecyl sulphate; Surfactant