Enrichment of polyunsaturated fatty acids from catfish oil with immobilized Rhizopus oryzea lipase

Abstract

   Nowadays, Pangasius hypophthalmus fillet is one of the main marine products in Vietnamese Mekong RiverDelta with over three hundred thousand tons per year. One of the byproducts of this industry is fat, about onehundred thousand tons per year. That byproduct has been only used in animal foodstuff industry after oil extractingor it becomes waste. In order to increase the quality of Pangasius hypophthalmus oil, we have enriched PUFA in theoil by hydrolysis with immobilized Rhizopus oryzea lipase. Lipase has been immobilized on celite by absorptionmethod. Immobilization experiments have been designed in a two-level full factorial model with three factors. Thefish oil has been hydrolyzed with immobilized lipase to enrich PUFA with optimized parameters found out: the ratioof enzyme to support of 1:10 g/g, the ratio of phosphate buffer volume to support weight of 30.55 ml/g, incubationtime of 5.15 hours. The result has showed that 60-minute hydrolysis is the most appropriate. Additionally, the oiliodine value has increased from 71.4 to 97.4, and DHA concentration has risen from 1156mg/kg to 1916mg/kg.