THE FERRET AS A MODEL FOR EVALUATION OF THE BIOAVAILABILITIES OF ALL-TRANS-BETA-CAROTENE AND ITS ISOMERS

The objective was to develop the ferret as a model for evaluation of t he bioavailabilities of natural and synthetic beta-carotenes in foods. For these studies, a low carotenoid purified diet was formulated that produced excellent food intake and adequate growth. After consuming t he diet for 16 d, ferrets were randomly assigned to one of three group s. For a 10-d period, they ingested a standardized amount of all-trans -beta-carotene (18 mumol/L) from either carrot juice, a test beverage of beta-carotene beadlets dispersed in fruit juices, or a control beve rage of beta-carotene beadlets dispersed in water. Accumulations of al l-trans-beta-carotene in the sera, livers and adrenals of ferrets that consumed the carrot juice were significantly lower (P < 0.02) compare d with those of ferrets that consumed the test or control beverages. T he content of a cis-isomer component relative to that of all-trans-bet a-carotene was higher in each beta-carotene beadlet-fortified beverage than in the liver and adrenal tissues of ferrets that ingested the be verage; the cis-isomer was not measurable in sera. The content of all- trans-beta-carotene relative to that of all-trans-alpha-carotene, a st ructural isomer, was higher in carrot juice than in sera of ferrets th at ingested the juice. We conclude that 1) all-trans-beta-carotene is less bioavailable from carrot juice than from beta-carotene beadlet-fo rtified beverages, and 2) there are apparent bioavailability differenc es between isomers of beta-carotene in ferrets.