Urinary excretion of Citrus flavanones and their major catabolites after consumption of fresh oranges and pasteurized orange juice: A randomized cross-over study.

SCOPE: Orange juice contains flavanones including hesperidin and narirutin, albeit at lower concentrations as compared to orange fruit. Therefore, we compared bioavailability and colonic catabolism of flavanones from orange juice to a 2.4-fold higher dose from fresh oranges. METHODS AND RESULTS: Following a randomized two-way cross-over design, 12 healthy subjects consumed a test meal comprising either fresh oranges or pasteurized orange juice, delivering 1774 and 751 µmol of total Citrus flavanones, respectively. Deglucuronidated and desulfated hesperetin, naringenin, and the flavanone catabolites 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid, 3-(3'-hydroxyphenyl)hydracrylic acid, 4-hydroxyhippuric acid, and hippuric acid were quantitated in 24-h urine by UHPLC-MS/MS. Differences in urinary hesperetin excretion were found to be nonsignificant (p = 0.5209) both after consumption of orange fruit (21.6 ± 8.0 µmol) and juice (18.3 ± 7.2 µmol). By analogy, postprandial flavanone catabolite excretions were highly similar between treatments. Excretion of 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid was inversely related to that of hesperetin, illustrating the catabolite/precursor relationship. CONCLUSION: Despite 2.4-fold higher doses, excretion of flavanones from ingested fresh orange fruit did not differ from that following orange juice consumption, possibly due to a saturation of absorption or their entrapment in the fiber-rich matrix of the fruit.

Bioavailability of ß-cryptoxanthin is greater from pasteurized orange juice than from fresh oranges - a randomized cross-over study.

SCOPE: Orange fruits and products thereof represent important dietary sources of carotenoids, particularly ß-cryptoxanthin. Since previous studies reported a positive effect of vegetable processing on carotenoid absorption, our objective was to compare the bioavailability of ß-cryptoxanthin from either fresh navel oranges (Citrus sinensis L. Osbeck) or pasteurized orange juice. METHODS AND RESULTS: The study was designed as a randomized 2-way cross-over study. Twelve volunteers consumed two meals delivering 744 µg of ß-cryptoxanthin from either fresh navel oranges or pasteurized orange juice. Eight blood samples were collected over 9.5 h after test meal consumption and analyzed using HPLC-DAD. Additionally, carotenoid bioaccessibility was assessed after in vitro digestion of the same test foods. ß-cryptoxanthin bioavailability from pasteurized orange juice was 1.8-fold higher than from fresh oranges (P = 0.011). Similarly, mean absorption of the non-dose adjusted carotenoids lutein (P = 0.301), zeaxanthin (P = 0.216), and zeinoxanthin (P = 0.090) were slightly higher from orange juice, although not reaching statistical significance. The in vitro digestion revealed a 5.3-fold higher bioaccessibility of ß-cryptoxanthin from orange juice. Dietary fiber contents in the test foods were inversely associated with carotenoid bioavailability. CONCLUSION: Orange juice represents a more bioavailable source of ß-cryptoxanthin than fresh oranges.

In vitro bioaccessibility of carotenoids, flavonoids, and vitamin C from differently processed oranges and orange juices [Citrus sinensis (L.) Osbeck].

Carotenoid, flavonoid, and vitamin C concentrations were determined in fresh orange segments and a puree-like homogenate derived thereof, as well as freshly squeezed, flash-pasteurized, and pasteurized juices. Lutein and ß-cryptoxanthin were slightly degraded during dejuicing, whereas ß-carotene levels were retained. Vitamin C levels remained unaffected, whereas flavonoid levels decreased 8-fold upon juice extraction, most likely due to the removal of flavonoid-rich albedo and juice vesicles. Likewise, the presence of such fibrous matrix compounds during in vitro digestion was assumed to significantly lower the total bioaccessibility (BA) of all carotenoids from fresh fruit segments (12%) as compared to juices (29-30%). Mechanical disruption of orange segments prior to digestion did not alter carotenoid BA, whereas pasteurization of the freshly squeezed juice slightly increased BA by 9-11%. In addition to carotenoid BA, the stabilities of hesperidin, narirutin, and vitamin C including dehydroascorbic acid during in vitro digestion were monitored, and applied analytical methods were briefly validated.