Determination of optimal processing conditions for hydrogenation of rice bran oil

Abstract

Hydrogenation has been practiced for over a century to improve the oxidative stability of vegetable oils for improved shelf life and to modify the solids content and melting characteristics of oil to formulate shortening and margarine products with desired physical properties. Based on that, this research was carried out to produce hydrogenated rice bran oil (RBO) using refined, bleached, and deodorized oil from rice bran. Nickel (Ni) is used as the catalyst. The key factors that change during pretreatment were identified as reaction time, temperature, and the amount of catalyst. The amount of catalysts used for the trials was filtered by using vacuum filtration after the reaction was completed. Moisture content, melting point, iodine value, peroxide value, fatty acid (free), and acid value were analyzed to check the oil properties. The above-mentioned physiochemical properties of RBO, hydrogenated palm oil (HPO), and hydrogenated RBO (HRBO) were determined, and the data were analyzed at 0.05 significant level. There was a significant difference between the samples. The optimum conditions for HRBO were reported as; 2g of Ni for 200g of RBO under the temperature of 180° C for 6 hours based on the results of less iodine value: 60.31 and, high melting point: 38°C than raw RBO. The HRBO was resulted free fatty acid value: 1.32%, acid value: 1.57%, peroxide value: not detected, iodine value: 60.31, melting point: 38°C, moisture content: 0.02%. Those values were compared with the HPO and RBO, and the raw RBO was shown free fatty acid value: 0.14%, acid value: 1.57%, peroxide value: not detected, iodine value: 95.21, melting point: 26.3°C, moisture content: 0.09%.