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.

Using black soldier fly larvae reared on fruits and vegetables waste as a sustainable dietary source of provitamin a carotenoids.

We showed that black soldier fly larvae reared on fruits and vegetables rich in provitamin A carotenoids can accumulate significant amounts of these vitamin A precursors. Using a simulated gastro-intestinal digestion model, we demonstrated that α- and ß-carotene from the larvae are as bioaccessible as from the fruits and vegetables they were reared on. We calculated that provitamin A carotenoid-rich larvae have the capacity to provide more vitamin A than fruits and vegetables rich in these molecules. Remarkably, the incorporation of usual quantities of these larvae in feed could cover the needs of several production animals for this vitamin. Thus, our findings suggest that rearing black soldier fly larvae on by-products or waste rich in provitamin A carotenoids could be a sustainable strategy to recycle a fraction of vitamin A back into the food chain and could represent a new approach to fight against vitamin A deficiency.

Temperature and storage time increase provitamin A carotenoid concentrations and bioaccessibility in post-harvest carrots.

The aim was to enhance provitamin A carotenoid (proVA CAR) concentrations and bioaccessibility in carrots by manipulating post-harvest factors. To that end, we assessed the effects of Ultraviolet-C light, pulsed light, storage temperature, and storage duration. We also measured CAR bioaccessibility by using an in vitro model. Pulsed light, but not Ultraviolet-C, treatment increased proVA CAR concentrations in the cortex tissue (p < 0.05). Longer storage times and higher temperatures also increased concentrations (p < 0.05). The maximal increase induced by pulsed light was obtained after treatment with 20 kJ/m2 and 3-days of storage at 20 °C. However, the positive effect induced by pulsed light decreased considerably over the next seven days. ProVA CAR in carrots with the highest concentrations also proved to be more bioaccessible (p < 0.05). Thus, proVA CAR concentrations in stored carrots can be increased significantly through storage times and temperatures. Pulsed light can also significantly increase proVA CAR concentrations, but only temporarily.

Influence of soy and whey protein, gelatin and sodium caseinate on carotenoid bioaccessibility.

Proteins could alter carotenoid bioaccessibility through altering their fate during digestion, due to emulsifying properties of resulting peptides, or influencing access of digestion enzymes to lipid droplets. In this investigation, we studied whether whey protein isolate (WPI), soy protein isolate (SPI), sodium caseinate (SC) and gelatin (GEL), added at various concentrations (expressed as percentage of recommended dietary allowance (RDA): 0, 10, 25 and 50%) would influence the bioaccessibility of lycopene, ß-carotene or lutein, added as pure carotenoids solubilized in oil, during simulated gastro-intestinal (GI) digestion. Protein and lipid digestion as well as selected physico-chemical parameters including surface tension, ζ-potential and micelle size were evaluated. Adding proteins influenced positively the bioaccessibility of ß-carotene, by up to 189% (p < 0.001), but it resulted in generally decreased bioaccessibility of lutein, by up to 50% (p < 0.001), while for lycopene, the presence of proteins did not influence its bioaccessibility, except for a slight increase with WPI, by up to 135% (p < 0.001). However, the effect depended significantly on the type of protein (p < 0.001) and its concentration (p < 0.001). While ß-carotene bioaccessibility was greatly enhanced in the presence of SC, compared to WPI and GEL, the presence of SPI strongly decreased carotenoid bioaccessibility. Neglecting individual carotenoids, higher protein concentration correlated positively with carotenoid bioaccessibility (R = 0.57, p < 0.01), smaller micelle size (R = -0.83, p < 0.01), decreased repulsive forces (ζ-potential, R = -0.72, p < 0.01), and higher surface tension (R = 0.44, p < 0.01). In conclusion, proteins differentially affected carotenoid bioaccessibility during digestion depending on carotenoid and protein species, with both positive and negative interactions occurring.

Mechanisms Governing the Transfer of Pure and Plant Matrix Carotenoids Toward Emulsified Triglycerides.

SCOPE: The study aims to assess the role of factors assumed to be involved in the transfer of carotenoids from plant matrices to dietary emulsions in the upper digestive tract. METHODS AND RESULTS: Transfer is first measured as a function of time of pure ß-carotene (ßC), lutein (LUT), and lycopene (LYC) to triglyceride (TG) droplets dispersed in water. Then the transfer to TG droplets stabilized with either bovine serum albumin (BSA), phospholipids (PL), or both is measured. Finally, transfer of tomato and spinach puree carotenoids to these emulsions is measured. The maximal transfer efficiency of the pure carotenoids to uncoated emulsions is very efficient, ranging from 59% to 77%. However, it is dramatically impaired, ranging from 0.5% to 31% (p < 0.05), when emulsions are stabilized by the emulsifiers. Conversely, when LUT, and to a less extent ßC, but not LYC, is provided by the vegetable purees, its maximal transfer efficiency is significantly higher for the coated emulsions than for the uncoated one. CONCLUSIONS: Emulsifiers can dramatically impair the transfer of pure carotenoids to emulsion TG while they can facilitate the transfer of carotenoids from plant matrices. This suggests that specific interactions between plant matrix compounds and emulsifiers can enhance the transfer efficiency of carotenoids.