Removal of Free Fatty Acids in edible oils by an efficient functionalized magnetic nanoparticles

A fast, sensitive, and simple method using magnetic nanoparticles (MNPs) coated by tetraethyl ortho silicate (TEOS) and modified with 1,1-dimethylbiguanide (Metformin), as an adsorbent has been successfully developed for removal of free fatty acids from oils [1]. The effect of contact time and concentration on the adsorption of oleic acid (OA) from ethanol–hexane solutions was investigated at room temperature using equilibrium batch experiments. The results showed that the adsorption is rapid ( 10 min) The maximum adsorption capacity of oleic acid was determined to be 286 mg g−1. Size, structure and magnetic property of the prepared modified magnetic nanoparticles (MNPs) were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and vibrating-sample magnetometer (VSM). Adsorption of FFA by metformin functionalized was proved by acid- base interactions between N and NH group and carboxylic acid groups. Desorption of fatty acids was readily achieved upon basic treatment and the regenerated magnetite nanoparticles were found to be recyclable for repeated use. The separation of fatty acids from olive and sunflower oils (as real sample) was investigated without added solvent [2]. MNPs were found to remove up to 96% of the fatty acids in the oil within 10 min with a 1 wt% load at room temperature, without alteration of composition and other conditions. Excellent adsorption capacity of the modified nanoadsorbent with other advantages such as reusability, easy separation by an external magnetic field, make it suitable adsorbent for removal of fatty acids [3].