Preparation and characterization of quinoa starch nanoparticles as quercetin carriers

•The preparation conditions of SNPs were optimized by a full factorial design.•Preparation factors and their interactions had significant effects on size of SNPs.•QSNPs were spherical with size of 166.25 nm prepared through nanoprecipitation.•QSNPs had better ability to protect quercetin bioactivity than MSNPs.