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

Abstract

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 β-Carotene in Carrots and Sweet Potatoes

“…The bioaccessibility of proVA carotenoids in carrots and sweet potatoes was measured using an in vitro digestion model, as previously described [8,15,16]. Of the raw grated carrots or sweet potatoes, 2 g was mixed with a meal consisting of 6.7 g mashed potatoes, 1.2 g ground beef and 200 µL olive oil (all purchased from a local supermarket).…”

Novel Biphasic In Vitro Dissolution Method Correctly Predicts the Oral Bioavailability of Curcumin in Humans

“…Furthermore, the characterization of formulations containing more than one active ingredient, which is common for plant extracts and dietary supplements, is challenging, and the use of these dissolution approaches might not be feasible . To overcome these limitations, biorelevant testing methods, such as biphasic dissolution approaches − or in vitro digestion models, ,− have been developed. In vitro digestion models typically use sequential mouth, gastric, and intestinal digestion steps to mimic the condition in the human gut.…”