14B-39

V. SY¹, A. Mihele, Y. Kakuda, and V. Abraham. (1) Department of Food Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada

JUSTIFICATION: The catalytic hydrogenation of edible oils is the single most important chemical reaction used by the edible oil industry to modify the functionality of liquid oils. Reducing the levels of polyunsaturated fatty acids and increasing the levels of saturated fatty acids during hydrogenation of edible oils, allows them to be used in a wide range of food products. Studies conducted over the past 10 years have implicated the consumption of trans fatty acids as a risk factor in the promotion of cardiovascular disease.

OBJECTIVES: The objectives of this study was to modify a conventional hydrogenator (Batch System) into a vapor phase hydrogenator (Continuous Spray System) and to compare the results of the batch system to the continuous spray system in terms of trans fatty acid formation.

METHODS: Refined, bleached and without added citric acid soybean oil was hydrogenated using a heterogeneous nickel catalyst (0.0125% w/w) at a temperature of 182°C and hydrogen pressures of 45, 60 and 90 psi.

RESULTS: Using the continuous spray system at a hydrogen pressure of 45 psi and iodine value of 70, results in a 10% decrease in trans fatty acids when compared to the batch system. As the hydrogen pressure was increased to 95 psi and iodine value reaching 65, the continuous spray system resulted in 16% reduction of trans fatty acids when compared to the batch system. However, at the hydrogen pressure of 60 psi, both the batch and continuous spray system showed no measurable difference in trans fatty acid formation.

SIGNIFICANCE: Since hydrogenated vegetable oils are the main source of trans fatty acids, this vapor phase method of reducing the formation of trans fatty acids during hydrogenation process would be an ideal way to reduce the levels of trans fatty acids in the diet.