Utilization of undesirable heat-induced precipitates/sediments in soy sauce production to fabricate nanoparticles for curcumin delivery.

This study aimed to utilize an unwanted by-product of soy sauce production, the heat-induced precipitates/sediments (HPSS), to fabricate HPSS nanoparticles using a pH-driven method for their use as nano-carriers of unstable curcumin. The results showed that curcumin could successfully complex with HPSS at pH 6.0, 7.0 and 8.0, via hydrogen bonding, electrostatic interactions and hydrophobic interactions, with high encapsulation efficiency (>96%), stability and DPPH radical scavenging activity. Comparable properties were found among the HPSS nanoparticles and derived HPSS-curcumin nanocomplexes obtained at the three pHs, although the HPSS nanoparticles had the highest curcumin loading amount (10.14 μg/mg) and greatest DPPH radical scavenging power (SC 50 0.89 μg/mL) at pH 7.0, and the nanocomplexed curcumin was most stable at pH 6.0. Thus, HPSS can be utilized as delivery vehicles for hydrophobic substances in food and medicinal applications, and pH is a critical variable governing the outcomes. Image 1 • An undesirable by-product of soy sauce production (HPSS) was successfully reutilized. • HPSS nanoparticles can be utilized as delivery vehicles for curcumin. • PH was proved to be a critical variable governing the outcomes. • Curcumin could successfully complex with HPSS at pH 6.0, 7.0 and 8.0. [ABSTRACT FROM AUTHOR]