Chitosan-coated nanoliposomes for efficient delivery of betanin with enhanced stability and bioavailability

Betanin is a high-value health-promoting food ingredient. However, the bioavailability of betanin is constrained by its low stability. In this study, for the first time, betanin was stabilized and delivered using chitosan-coated nanoliposomes (CC-NLs). The CC-NLs were firstly synthesized and characterized. The results showed that increasing chitosan concentration from 0% to 1.0% increased particle size of CC-NLs from 156.4 nm to 217.2 nm. With the use of CC-NLs prepared with 0.6% chitosan, it was found that increasing pH from 1.5 to 9.0 reduced zeta potential of CC-NLs from 8.62 mv to-9.65 mv while the average size of CC-NLs of 221.40 nm peaked at pH 5.5. In aqueous solution, 29.0% of loaded betanin was released from NLs compared to 15.8% from CC-NLs. The in vitro digestion analysis indicated that uncoated NLs and CC-NLs had similar stabilities and relatively stable in oral and gastric fluids. However, in intestinal fluid, the average size of both NLs and CC-NLs were significantly reduced due to bile salt and trypsin. Furthermore, in vitro antioxidant activity assay results showed that betanin delivered by CC-NLs had the highest ORAC and PSC values. This study demonstrated that betanin could be efficiently delivered by CC-NLs with improved stability and bioavailability. The information generated from this study is very useful for the applications of betanin in functional food, pharmaceutical and cosmetics industry.