Cavitation assisted novel method for synthesis of starch nanoparticles

Abstract

Starch nanoparticles (SNPs) have drawn significant attention by researchers in the last decade because of their unique mechanical properties, renewable nature, low cost and numerous industrial applications. In this paper we present the first detailed study of the use of cavitation under alkaline conditions followed by precipitation for synthesis of rice SNPs. For acoustic cavitation, the effect of sonication time and sonication power and for hydrodynamic cavitation the effect of inlet pressure, number of passes and number of holes of orifice plate on particle size distribution and average particle size of SNPs was investigated. Surface morphology of the native and SNPs was elucidated using scanning electron microscopy. Physicochemical changes in formed SNPs were investigated by FTIR spectroscopy and XRD technique. Acoustic cavitation (30 kHz, 175 W) produced SNPs having size as low as 70 nm in 20 min of sonication time. For hydrodynamic cavitation, higher inlet pressure, higher number of passes and orifice plates with more holes, produced particles with narrow distribution. Combination of alkali and cavitation treatment resulted in formation of SNPs with reduced crystallinity compared to native starch particles. Hydrodynamic cavitation assisted synthesis of SNPs was found to be much more energy efficient compared to acoustic cavitation.