Preparation of active polysaccharide-loaded maltodextrin nanoparticles and their stability as a function of ionic strength and pH

•Maltodextrin nanoparticles (MNPs) with controllable particle sizes were prepared.•MNPs prepared with different emulsifier had different morphology, size and structure.•MNPs prepared at different ratio (maltodextrin solution: ethanol) had different size.•The active polysaccharides-loaded MNPs were more stable against salt and pH.

Active polysaccharides (APs) are known to have a wide variety of biological functions, such as anti-viral, anti-oxidant, hypoglycemic, and lipid-lowering effects. However, the extremely low bioavailability of APs restricts their bioactivity in vivo; therefore, the development of a biopolymer nanoparticle carrier is a promising solution. For the first time, we have successfully prepared maltodextrin nanoparticles (MNPs) with controllable particle sizes. The influence of different emulsifier types and volume ratios of a maltodextrin solution to absolute ethanol on the morphology and size of the MNPs was examined, and the smallest MNPs (30-90 nm) were obtained when the volume ratio was 1:10 and the emulsifier was Tween 80. Furthermore, tea, pumpkin, and balsam pear polysaccharides were loaded on the MNPs with loading efficiencies of 63.5, 68.7, and 72.1%, respectively. Compared with the MNPs, the AP-loaded MNPs were more stable in a high salt content, or under a gastric pH of 1.2 and physiological pH of 7.4 conditions. These MNPs may serve as effective nanocarriers by delivering APs to enhance their bioavailability.