Application of Artificial Neural Network for Yield Prediction of Lipase-Catalyzed Synthesis of Dioctyl Adipate Mohd Basyaruddin Abdul Rahman & Naz Chaibakhsh & Mahiran Basri & Abu Bakar Salleh & Raja Noor Zaliha Raja Abdul Rahman Received: 3 July 2008 / Accepted: 2 December 2008 / Published online: 9 January 2009 # Humana Press 2009 Abstract In this study, an artificial neural network (ANN) trained by backpropagation algorithm, Levenberg–Marquadart, was applied to predict the yield of enzymatic synthesis of dioctyl adipate. Immobilized Candida antarctica lipase B was used as a biocatalyst for the reaction. Temperature, time, amount of enzyme, and substrate molar ratio were the four input variables. After evaluating various ANN configurations, the best network was composed of seven hidden nodes using a hyperbolic tangent sigmoid transfer function. The correlation coefficient (R 2 ) and mean absolute error (MAE) values between the actual and predicted responses were determined as 0.9998 and 0.0966 for training set and 0.9241 and 1.9439 for validating dataset. A simulation test with a testing dataset showed that the MAE was low and R 2 was close to 1. These results imply the good generalization of the developed model and its capability to predict the reaction yield. Comparison of the performance of radial basis network with the developed models showed that radial basis function was more accurate but its performance was poor when tested with unseen data. In further part of the study, the feedforward backpropagation model was used for prediction of the ester yield within the given range of the main parameters. Keywords Esterification . Lipase . Adipate ester . Neural network . Modeling . Prediction Appl Biochem Biotechnol (2009) 158:722–735 DOI 10.1007/s12010-008-8465-z M. B. Abdul Rahman (*) : N. Chaibakhsh : M. Basri Department of Chemistry, Faculty of Science, 43400 UPM, Serdang, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia e-mail: basya@science.upm.edu.my M. B. Abdul Rahman Structural Biology Research Center, Malaysia Genomic Institute, MTDC-UKM Smart Technology Center, UKM Bangi, 43600 Bangi, Selangor, Malaysia A. B. Salleh : R. N. Z. R. Abdul Rahman Laboratory of Industrial Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Malaysia