Bioaccessibility, cellular uptake and transepithelial transport of α-tocopherol and retinol from a range of supplemented foodstuffs assessed using the caco-2 cell model

The bioaccessibility, or amount of a nutrient available for gastrointestinal absorption, can be determined using an in vitro digestion model, the addition of the resultant digestate to a caco-2 transwell model system yields an approximation of nutrient bioavailability. The objective of the present study was to compare the bioaccessibility and bioavailability of α-tocopherol and retinol from a range of digested foodstuffs. Minced pork, beef and turkey and apple sauce, bread and mayonnaise were supplemented with α-tocopherol-acetate and retinol-acetate prior to being subjected to an in vitro digestion procedure. The aqueous fraction of each of the digested foodstuffs was then added to a caco-2 transwell model and the transepithelial transport was determined. The findings of the present study indicate that α-tocopherol and retinol are more bioaccessible from supplemented meat products than from supplemented apple sauce, bread and mayonnaise. It was found that turkey meat facilitated the highest bioaccessibility and subsequent cellular uptake and transport of retinol. The cellular uptake and secretion of α-tocopherol was similar for all samples.