Bleaching of Groundnut Oil Using Activated Rice Husk: A Suitable Alternative to Commercial Adsorbents

Abstract

Absorbent bleaching of crude groundnut oil was performed using activated rice husk as an adsorbent. The study focused on refining the oil by eliminating unwanted components. Response surface methodology was employed to optimize the bleaching process by analyzing the impact of time, adsorbent dosage, particle size, and temperature. Interactive effects on absorbance and peroxide value were also investigated. Bleaching efficiency was determined by measuring absorbance, with a 46.78% reduction observed (from 0.962 to 0.512). The peroxide value decreased from 13.333 to 3.571 mEq/kg of oil. Physiochemical properties were within the acceptable codex brought range. Fourier-transform infrared spectroscopy revealed decreased impurity concentrations, such as nitrile functional groups and unsaturated fatty acids. In conclusion, bleaching positively affected the oil's physiochemical properties, and rice husk proved to be a suitable alternative to commercial adsorbents.