Improved hydrogenation process for margarine production with no trans fatty acid formation by non-thermal plasma with needle-in-tube configuration

Abstract

Non-thermal dielectric barrier discharge (DBD) plasma with needle-in-tube configuration was used to improve hydrogenation reaction for trans -fat free margarine production. Refined palm olein was used as raw material with operating conditions at ambient pressure, room temperature (29 °C) and no catalyst. Effects of hydrogen gas (H 2 ) concentration, input power, gas flow rate, discharge gap size and reaction time on fatty acid compositions and properties of hydrogenated refined palm olein after plasma treatment was evaluated. Lowest iodine value (IV) was achieved with reduction from 60.75 to 23.56 with increase in saturated fatty acid composition from 40.82 ± 0.05 to 68.70 ± 0.07% and decrease in unsaturated fatty acid composition from 59.11 ± 0.12 to 31.39 ± 0.01% under the condition of 0.5 L/min gas flow rate with 100% H 2 , 40 W input power, 0.5 cm gap size and 15 h reaction time. In addition, no trans -fat was detected by GC-MS analysis. Slip melting point (SMP) was increased from 9.33 ± 0.5 to 36.33 ± 0.5 °C. Acid value (AV) was reduced from 0.47 ± 0.02 to 0.32 ± 0.03 mg KOH/g oil. Texture of produced margarine was similar to that of commercial one. Generated hydrogen free radicals were hypothesized to perform hydrogenation by reacting with carbon-carbon double bonds (π-bonds), converting poly- and monounsaturated fatty acids into saturated ones. This highly effective catalyst-free plasma hydrogenation system can be used as alternative, environmentally friendly and economically feasible method to produce trans -fat free margarine. • Production of trans -fat free margarine via non-thermal plasma hydrogenation of palm olein. • Highly environmental-friendly, requiring no catalyst under low temperature and pressure. • Reduced acid value provides increased storage time and longer shelf life.