Enhancement of some natural antioxidants activity via microbial bioconversion process using gamma irradiation and incorporation into gold nanoparticles

Document Type


Publication Date



Aspergillum royal was used to enhance the mobilization of antioxidants of soybean matrix along with garlic as a co-substrate by modulating polyphenolic substances during solid-state fermentation. The levels of [3-glucosiclase enzyme, total phonemic content, DPPH free radical scavenging activity and reducing power were investigated during fermentation. Exposure of fungal cultures to gamma irradiation at a dose of 0.75 key yielded relative increase of DPPH free radical scavenging activity, reducing power and total phenol content by about 10%, 54% and 29%, respectively compared to un-irradiated cultures. The antioxidant activity was optimized employing factorial design. The variables evaluated were; pH, temperature, incubation period, inoculums size and humidity, with optimal conditions of 7, 35°C, 6 days, 9 ×l0 6spores/ml and 60%, respectively, with DPPH free radical scavenging activity as response. The maximum DDPH free radical scavenging activity obtained was 95.4%. The most significant variables reported were moisture content and temperature. The aqueous fermented extract was used for rapid preparation of gold Nan particles (AuNPs) confirmed by UV-Vis spectrometry, dynamic light scattering, FT-IR spectrometry and TEM analysis which revealed morphology of spherical AuNPs with size ranging from 7-20 nm. Mobilized polyphonies are suggested to be responsible for synthesis and stabilization of gold Nan particles. The reaction was rapid and completed within one minute. © IDOSI Publications, 2012.

This document is currently not available here.