beta-carotene-loaded liposome dispersions stabilized with xanthan and guar gums: Physico-chemical stability and feasibility of application in yogurt

摘要

The objective of this work was to produce beta-carotene-loaded liposomes using proliposomes and to test their incorporation in yogurts. Multilamellar liposome dispersions were stabilized by the addition of a mixture of xanthan and guar gums as thickeners, and vesicles exhibited an average diameter of approximately 2000 nm. The liposomes were capable of protect the beta-carotene from degradation for a period of 95 days; in fact, nearly 90% of the encapsulated carotenoids were preserved after this time. The dispersions were characterized by transmission electron microscopy, differential scanning calorimetry and rheology. The thermal analyses showed that neither the beta-carotene nor the gums affected the liposome bilayer structure. Moreover, the mixture of gums was highly effective in avoiding beta-carotene-loaded liposome aggregation over the storage time, and the data showed that a higher thickener concentration did not necessarily construct a more stable system. The physico-chemical characterization of the yogurts showed that their texture of both formulations A and B was not affected by the incorporation of the liposomes. The grades assigned were 7.40 +/- 1.22 and 6.87 +/- 1.43, respectively. This shows that they did not differ significantly, indicating the real possibility that at least part of the artificial colorants can be replaced by the encapsulated beta-carotene-loaded liposomes