In vitro digestion-assisted development of a β-cryptoxanthin-rich functional beverage; in vivo validation using systemic response and faecal content

• Different lipid emulsions modify the in vitro bioaccessibility of β-Cx.
• A food matrix containing milkfat globule membrane is an adequate delivery system for β-Cx.
• In vitro digestion is a suitable approach to develop functional foods but not fully predictive.
• In vivo serum response does not predict reliably the availability of carotenoids at the colon.

Bioavailability of carotenoids is low and significant amounts reach the colon where they may be biologically active. We aimed to optimize a previously developed beverage designed to improve cardiovascular and bone remodelling markers in post-menopausal women. By assessing different lipid emulsions (soy lecithin, milkfat globule membrane (MFGM) and olive oil) on the in vitro bioaccessibility of β-Cryptoxanthin and phytosterols, a MFGM containing beverage was selected and resulted stable over time (recovery >95%) under in vitro digestion and simulated anaerobic conditions. This beverage was tested in a randomized human trial (n = 38) by evaluating systemic response and the colonic availability of β-Cryptoxanthin. Consumption for six weeks provoked an increment in serum β-Cryptoxanthin of 38.9 μg/dl (CI 95%; 31.0, 46.8; p < 0.001). In faeces, free β-Cryptoxanthin, tentatively identified β-Cryptoxanthin esters and the ratio cis-/trans-β-carotene approached the profile in the beverage and after in vitro digestion but it was different from serum. In conclusion, in vitro digestion-assisted approach appears adequate to develop functional foods although in vivo validation should consider both systemic response and the availability at the colon.