Production of partially hydrogenated soybean oil with low trans-fatty acids using surface dielectric barrier discharge cold plasma

This study examined the feasibility of applying surface dielectric barrier discharge cold plasma (SDBDCP) to partially hydrogenate crude soybean oil. The oil sample was treated for 13 h using SDBDCP at 15 kV with 100% hydrogen gas under room temperature and atmospheric pressure. Fatty acid composition, iodine value, refractive index, carotenoid content, melting point, peroxide value, and free fatty acids content (FFA) were investigated during SDBDCP treatment. Analysis of fatty acid composition demonstrated an increase in the content of saturated and monounsaturated fatty acids (from 41.32% to 55.3%) and a decrease in the content of polyunsaturated fatty acids (from 58.62% to 40.98%), which resulted in a reduction of the iodine value to 98.49 over the treatment time. Also, the fatty acid profile indicated that the total detected level of trans-fatty acids was very low (0.79%). After a 13-h treatment, the samples showed a refractive index of 1.4637, melting point of 10°C, peroxide value of 4.1 meq/kg, and FFA content of 0.8%. In addition, the results revealed a 71% decline in the carotenoid content of the oil sample due to the saturation of their double bonds. Therefore, these findings suggest that SDBDCP can be effectively used for hydrogenation along with bleaching oil.