Lipozyme TL IM-catalyzed interesterification for the modification of margarine fats was carried out in a batch reactor at 70°C with a lipase dosage of 4%. Solid fat content (SFC) was used to monitor the reaction progress. Lipasecatalyzed interesterification, which led to changes in the SFC,was assumed to be a first-order reversible reaction. Accordingly,the change in SFC vs. reaction time was described by an exponential model. The model contained three parameters, each with a particular physical or chemical meaning: (i) the initial SFC (SFC0), (ii) the change in SFC (ΔSFC) from the initial to the equilibrium state, and (iii) the reaction rate constant value (k). SFC0 and ΔSFC were related to only the types of blends and the blend ratios. The rate constant k was related to lipase activity on a given oil blend. Evaluation of the model was carried out with two groups of oil blends, i.e., palm stearin/coconut oil in weight ratios of 90:10, 80:20, and 70:30, and soybean oil/fully hydrogenated soybean oil in weight ratios of 80:20, 65:35, and 50:50. Correlation coefficients higher than 0.99 between the experimental and predicted values were observed for SFC at temperatures above 30°C. The model is useful for predicting changes in the SFC during lipase-catalyzed interesterification with a selected group of oil blends. It also can be used to control the process when particular SFC values are targeted.
|Journal||Journal of the american oil chemists society|
|Publication status||Published - 2004|
Zhang, H., Pedersen, L. S., Kristensen, D., Adler-Nissen, J., & Holm, H. C. (2004). Modification of margarine fats by enzymatic interesterification: Evaluation of a solid-fat-content-based exponential model with two groups of oil blends. Journal of the american oil chemists society, 81(7), 653-658.