The Incorporation of Curcuminoids in Gamma-Cyclodextrins Improves Their Poor Bioaccessibility, Which Is due to Both Their Very Low Incorporation into Mixed Micelles and Their Partial Adsorption on Food.

SCOPE: Turmeric curcuminoids mainly consist of curcumin (CUR), demethoxycurcumin (dCUR), and bisdemethoxycurcumin (bdCUR). CUR displays low bioavailability, partly due to poor solubilization in the intestinal lumen during digestion, while data for dCUR and bdCUR are scarce. The study aims to investigate the bioaccessibility of curcuminoids from turmeric extracts or from gamma-cyclodextrins, considering potential interactions with food. METHODS AND RESULTS: Using an in vitro digestion model (correlation with CUR bioavailability: r = 0.99), the study shows that curcuminoid bioaccessibility from turmeric extract without food is low: bdCUR (11.5 ± 0.6%) > dCUR (1.8 ± 0.1%) > CUR (0.8 ± 0.1%). Curcuminoids incorporated into gamma-cyclodextrins display higher bioaccessibilities (bdCUR: 21.1 ± 1.6%; dCUR: 14.3 ± 0.9%; CUR: 11.9 ± 0.7%). Curcuminoid bioaccessibility is highest without food (turmeric extract: 2.0 ± 0.1%; gamma-cyclodextrins: 12.4 ± 0.8%) and decreases with a meat- and potato-based meal (turmeric extract: 1.1 ± 0.2%; gamma-cyclodextrins: 2.4 ± 0.3%) or a wheat-based meal (turmeric extract: 0.1 ± 0.0%; gamma-cyclodextrins: 0.3 ± 0.1%). Curcuminoids exhibit low (<10%) incorporation efficiencies into synthetic mixed micelles (bdCUR > dCUR > CUR). CONCLUSIONS: bdCUR and dCUR show greater bioaccessibilities versus CUR. Food diminishes curcuminoid bioaccessibility, likely by adsorption mechanisms. Gamma-cyclodextrins improve curcuminoid bioaccessibility.

Post-Harvest Atmospheric Pressure and Composition Modify the Concentration and Bioaccessibility of α- and ß-Carotene in Carrots and Sweet Potatoes.

Provitamin A (proVA) carotenoid synthesis and degradation are strongly influenced by environmental factors, including during post-harvest storage. Hypobaric and hyperbaric storages increase the shelf-life of many crops, but their effects on proVA carotenoids are not known. Our aim was to investigate the effects of modifications of atmospheric pressure and composition on α- and ß-carotene concentration and bioaccessibility during the post-harvest storage of carrots and sweet potatoes. Vegetables were stored for 11-14 days at 20 °C in the dark in chambers with modified pressure and O2 concentrations. In carrots, α- and ß-carotene concentrations increased significantly during storage, but compared to the control, they were significantly lower in hyperbaria (-23 and -26%, respectively), whereas they did not differ significantly in hypoxia and hypobaria. In sweet potatoes, α- and ß-carotene concentrations decreased significantly during storage, but neither hypoxia, hypobaria nor hyperbaria led to any significant change compared to the control. There was a significant increase for carrot α- and ß-carotene bioaccessibility in hypobaria and hyperbaria, while there was a significant decrease for sweet potato ß-carotene bioaccessibility in hypobaria/hypoxia and normobaria/hypoxia (-45% and -65% vs. control, respectively). Atmospheric pressure and composition during the post-harvest storage of carrots and sweet potatoes modified the concentration and bioaccessibility of proVA carotenoids.

Reduction of pulse "antinutritional" content by optimizing pulse canning process is insufficient to improve fat-soluble vitamin bioavailability.

Some bioactive compounds found in pulses (phytates, saponins, tannins) display antinutritional properties and interfere with fat-soluble vitamin bioavailability (i.e., bioaccessibility and intestinal uptake). As canned chickpeas are consumed widely, our aim was to optimize the chickpea canning process and assess whether this optimization influences fat-soluble vitamin bioavailability. Different conditions during soaking and blanching were studied, as was a step involving prior germination. Proteins, lipids, fibers, vitamin E, lutein, 5-methyl-tetrahydro-folate, magnesium, iron, phytates, saponins and tannins were quantified. Bioaccessibility and intestinal uptake of vitamin D and K were assessed using in vitro digestion and Caco-2 cells, respectively. Significant reductions of phytate, saponin and tannin contents (-16 to -44%), but also of folate content (up to -97%) were observed under optimized canning conditions compared with the control. However, bioaccessibility and cellular uptake of vitamin D and K remained unaffected after in vitro digestion of test meals containing control or optimized canned chickpeas.