Iranian Journal of Chemical Engineering (IJChE)

Abstract The chemical interesterification (CIE) process is a promising approach to modifying and improving oils and fat structure. In this study, CIE of fully hydrogenated soybean oil (FHSO) and sunflower oil (SFO) was performed. Different initial blends with various mass ratios of 20-45% FHSO (coded as S1, S2, S3, and S4) were converted to interesterified samples (Si-1, Si-2, Si-3, and Si-4, peer-to-peer). The interesterified samples (60% content) were used in different margarine formulas with 40% palmolein PO (M1, M2, M3, M4), and margarines enriched with beta-carotene, to compensate for the reduction of carotene during the oil decolorization process during refining. Esterification caused a significant decrease in the solid fat content (SFC) of initial fat blends and fatty acid profile analysis confirmed just less than 0.17-0.3% of trans fatty acid content (According to the definition of zero trans less than 0.5 g/12 g serving). Differential scanning calorimetry (DSC) measurement indicated that the interesterified samples possess lower melting points while showing binary or ternary crystallization peaks. The Polarized light microscopy (PLM) confirmed the presence of fine, desirable β´spherulite crystals, which are effective in creating the proper texture in margarine. Formulated margarines were evaluated and compared with one type of commercial margarine (as a control sample). According to the texture profile analysis (TPA) and organoleptic results, the M3 formula was chosen as the best formulation for margarine preparation (using Si-3 blending with the 35: 65 ratios of FHSO to SFO).

Abstract In this study, a kinetic model is proposed for Sunflower oil methanolysis in which the effect of the interfacial area on the reaction system has been investigated. The model is based on the combination of mass transfer and kinetics. Rate constant of the reaction is obtained by fitting of the experimental data with the model. Based on this model, activation energy is equal to E/R=3390 K. This model was applied to the transesterification of soybean oil with some modifications on Misek’s equation and interfacial tension correlation. Methyl ester production at two different mixing intensities was evaluated. By using this model, theoretical conversion is calculated and is compared with the experimental data taken from literature. An acceptable agreement has been obtained between two sets of data. Based on the experimental data shown in the paper, agitator speed has no significant effect on the conversion. Therefore, it can be concluded that at a temperature of 55 °C or higher, the model parameter approaches to the rate constant of reaction and the agitation speed does not affect the kinetics.