Microcapsules and Nanoliposomes Based Strategies to Improve the Stability of Blueberry Anthocyanins

Abstract

Blueberry anthocyanins are water-soluble natural pigments that can be used as both natural antioxidants and natural colorants. However, their structural instability greatly limits their application in the food, pharmaceutical, and cosmetic industries. In this study, blueberry anthocyanin microcapsules (BAM) and blueberry anthocyanin liposomes (BAL) were fabricated based on blueberry anthocyanins. Film dispersion methods were used to prepare the BAL. Their preparation processes were optimized and compared to improve the stability of the blueberry anthocyanins following exposure to light and high temperatures. The BAM were prepared through complex phase emulsification. The blueberry anthocyanins were protected by the shell materials composed of sodium alginate after being formed into BAM. Under the optimal conditions, the embedding rate of BAM and BAL can reach as high as 96.14% and 81.26%, respectively. In addition, the particle size, zeta potential, microtopography, and structure feature information of the BAM and BAL were compared. The average particle sizes of the BAM and BAL were 9.78 μm and 290.2 nm, respectively, measured using a laser particle size analyzer, and the zeta potentials of the BAM and BAL were 34.46 mV and 43.0 mV, respectively. In addition, the optimal preparation processes were determined through single-factor and response surface optimization experiments. The most important factors in the single-factor experiment for the preparation of microcapsules and liposomes were the content of CaCl2 and the amount of anthocyanin. The preservation rates in the light and dark were also compared, and the thermal stabilities of the BAM and BAL were characterized through differential thermal scanning. The results showed that both the BAM and BAL maintained the stability of blueberry anthocyanins, and no significant difference was found between the indices used to evaluate their stability. The results of this study provide theoretical support for the development of effective systems to maintain the stability of anthocyanins, thereby improving their bioavailability after ingestion by humans.