Stabilisation of natural anthocyanins by micellar Systems

In this paper, we discuss the influence of different micellar systems on th e degradation of natural anthocyans. either glycosides and aglycones. at pH values ranging from 2.8 to 6.0. The interaction of anthocyanins, in suitab le dispersed systems such as negative micelles of sodium dodecylsulphate (S DS), consistently increased their chemical stability in aqueous solutions. The results of these experiments point out how both the number of available negative charges and the presence of an organised distribution of the nega tive charges on the micellar surface appear to be necessary conditions to a chieve the anthocyanins' stability and colour retention. The sodium dodecyl benzensulphonate (SDBS). containing an aromatic ring near the negative surf ace of the micelle, seems to increase the rate of decomposition. Preliminar y findings of circular dicroism (CD) investigation allowed us to hypothesis e tl-rut these pigments undergo an intermolecular self-association process induced by the SDS micelles and this: phenomenon presumably contribute to i ncrease stability. (C) 2001 Elsevier Science B.V. All rights reserved.