Synthesis and Characterization of Fatty Acid Diacylglycerols from Rice Husk Oil via Catalytic Glycerolysis

Rice husk is an abundant agro-industrial residue containing small amounts of lipids rich in unsaturated fatty acids, which can serve as a renewable feedstock to produce functional glycerides. In this study, a sustainable approach for the synthesis of fatty acid diacylglycerols (DAG) from rice husk-derived oil via catalytic glycerolysis is proposed. The oil was extracted using Soxhlet extraction, where ethyl acetate showed the highest efficiency with a yield of ۲.۸۲%. The extracted oil was subjected to glycerolysis at ۲۲۰ °C for ۴ h in the presence of alkaline catalysts. This process enables the reversible conversion of triglycerides into mono- and DAG, with product distribution depending on reaction conditions. Among the investigated catalysts, KOH and CaO demonstrated comparable catalytic performance, producing diglyceride-rich fractions with yields of ۶۸.۹% and ۶۷.۴%, respectively, whereas NaOH showed lower activity (۵۷.۷%). The reaction products were purified by selective crystallization and column chromatography, allowing effective separation of glyceride fractions. Structural characterization using FTIR (Fourier-transform infrared spectroscopy) and GC–MS (gas chromatography–mass spectrometry) confirmed the formation of ester bonds and the presence of fatty acid glycerides. The results demonstrate that rice husk oil can be efficiently converted into DAG-rich products, offering a sustainable route for producing functional lipids with potential applications in food, pharmaceutical, and cosmetic industries.

کلیدواژه ها:

Rice oil ، glycerolysis ، Fatty acid diglycerides ، Functional lipids ، Agro-industrial waste valorization