LIMONIN AND NARINGIN REMOVAL FROM GRAPEFRUIT JUICE WITH NARINGINASE ENTRAPPED IN CELLULOSE TRIACETATE FIBERS

Naringin and limonin are two bitter components of some citrus products such as grapefruit juice. Naringin could be removed by hydrolysis with immobilized naringinase and limonin might be removed by adsorption with cellulose monoacetate gel beads. Cellulose triacetate fibers show a similar limonin adsorption capacity as cellulose monoacetate gel beads. Thus when naringinase from Penicillium sp. was entrapped in such fibers, an enzyme column was made which could remove both bitter components simultaneously. When grapefruit juice was debittered with this enzyme column, sugar components, total organic acids and turbidity were not affected. The enzyme column could be regenerated by washing with warm water. In addition, operational stability of the enzyme column was satisfactory. Such enzyme column could be considered for industrial use.