β-Cryptoxanthin fromCitrusjuices: assessment of bioaccessibility using anin vitrodigestion/Caco-2 cell culture model

Abstract

β-Cryptoxanthin (β-CX), a provitaminic carotenoid of potential interest for health, is found principally inCitrusfruit in both free and esterified forms. Little is known about the intestinal absorption of β-CX especially with regard to the esterified forms. The aim of this study was to evaluate the absorption of free and esterified β-CX using simulated digestion coupled with the Caco-2 model. Bioaccessibility was investigated by measuring the transfer of carotenoids from different citrus juices into micelles using anin vitrodigestion system. Then, carotenoid uptake was evaluated by adding carotenoid-rich micelles (from thein vitrodigestion) or synthetic micelles (made from synthetic lipids and carotenoids purified from citrus juice) to human intestinal cells (Caco-2 TC7 clone). Our results showed that β-cryptoxanthin esters (β-CXE) were partially hydrolysed during thein vitrodigestion. The bioaccessibility of free β-CX measured was significantly higher (40 (sd1·05) %) than that of β-carotene (30 (sd1·9) %) and β-CXE (16 (sd1·5) %). In the same way, the incorporation of free β-CX (27 (sd1·01) %) into synthetic micelles exceeded (P < 0·05) that of β-carotene (10 (sd0·7) %) and β-CXE (8·8 (sd0·4) %). In the case of micelles fromin vitrodigestion, the uptake of β-carotene, free β-CX and β-CXE forms by Caco-2 cells was 14·3 (sd1·8), 3·9 (sd1·3), and 0·7 (sd0·08) % respectively. These results showed a preferential uptake by Caco-2 cells of β-carotene and free β-CX compared with the two esters of β-CX.