14B-30

S. P. J. N. Senanayake and F. SHAHIDI. Department of Biochemistry, Memorial University of Newfoundland, St. John's, NF A1B 3X9, Canada

Borage oil is a rich source of gamma-linolenic acid (GLA; 18:3n6). GLA has been used in the treatment of certain skin-related disorders as well as a variety of other diseases. On the other hand, docosahexaenoic acid (DHA; 22:6n3) is considered important for proper function of nervous system and visual acuity. A modified oil that contains both GLA and DHA may be of interest because of its optimal health benefits.The objective of this study was to optimize the reaction conditions for incorporation of DHA into borage oil by immobilized lipase from Candida antarctica. Variables examined were the amount of enzyme, incubation temperature and incubation time.Lipase-catalyzed acidolysis of borage oil with DHA was optimized using response surface methodology (RSM). The reaction variables examined were the amount of enzyme (100-200 U), incubation temperature (30-60oC) and incubation time (18-30 h). Up to 29.1% DHA was incorporated into borage oil under optimum reaction conditions over a one day period. Analysis of variance (ANOVA) showed that 94% (R2=0.94) of the observed variation was explained by the polynomial model. The reproducibility of the model was satisfactory as coefficient of variation was only 3.5. Lack of fit test revealed a non-significant value for the model equation, indicating that the regression equation was adequate for predicting the degree of DHA incorporation under any combination of the variables. Borage oil containing DHA was successfully produced and may be used in certain nutritional and therapeutic applications.