Influence of lipid content and dilution on properties and stability of nanostructured lipid carriers (NLCs) prepared from rambutan (Nephelium lappaceum L.) kernel fat and evaluation of their beta-carotene loading capacity

摘要

The effects of lipid content and dilution on the properties and stability of nanostructured lipid carriers (NLCs) prepared from rambutan (Nephelium lappaceum L.) kernel fat were investigated. The beta-carotene-loading capacity of the NLCs was also evaluated. NLCs containing various lipid phase concentrations (5, 10, and 15 wt%) were prepared using Tween 80 as the emulsifier with a lipid to emulsifier weight ratio of 1:0.2. The results showed that an increase in the lipid content up to 15 wt% had no effect on the zeta-potential, particle size and polydispersity index but resulted in a higher particle density. All samples showed no phase separation during storage at 25 degrees C for 28 days; however, the relative recrystallization index (RRI) increased. Dilution of concentrated NLC (15 wt%) to a lower lipid content (5 and 10 wt%) produced no differences in the particle characteristics and stability during storage. NLCs loaded with beta-carotene at different concentrations (0, 0.5, and 1 wt% of the lipid phase) exhibited desirable characteristics and had high encapsulation efficiency (similar to 97%) over 28 days of storage. These results demonstrated that NLC prepared from rambutan kernel fat can be used to entrap lipophilic bioactive components which could be used as ingredients in functional food products.