Influence of sprouting on the bioaccessibility and bioactivity of benzoxazinoids, phenolic acids, and flavonoids of soft and hard wheat cultivars.

Grain germination increases the contents of benzoxazinoids and the antioxidant capacity of wheat and differentially affects the phytochemical composition of hard and soft wheat cultivars. It was investigated whether wheat cultivars (sprouted or not) with distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in relation to changes in phytochemical compounds, bioaccessibility and antioxidant capacity during simulated gastrointestinal digestion of a tabbouleh preparation. Sprouting increased the nominal amount of phytochemicals in tabbouleh resulting in increased release of phenolic acids (up to 7.5-fold) and benzoxazinoids (up to 12.5-fold) during all digestion phases besides higher bioaccessibility (up to 2.8-fold). Sprouting caused greater increase in the bioaccessibility of phenolic acids for the soft wheat cultivar (4.5-fold) than for the hard cultivar (1.9-fold) and it increased the colon available index of phenolic acids only for the soft cultivar (1.8-fold). Flavonoids, mainly represented by apigenin glycosides, were marginally increased after sprouting but underwent relative increase along digestion being the major phytochemicals found in the bioaccessible fraction obtained after intestinal digestion (73-94% of total phytochemicals). The increase in apigenin glycosides was associated to the increase of in vitro and intracellular antioxidant capacity of tabbouleh along digestion. Sprouting increased the peroxyl radical removal capacity of tabbouleh in the gastric phase and in the non-bioaccessible fraction regardless of the cultivar. The highest hydroxyl radical removal capacities were found in non-sprouted cultivars, especially in the soft texture cultivar in the undigested and bioaccessible fractions. The bioaccessible fraction obtained after wheat digestion was more efficient to scavenge intracellular ROS than undigested samples, the highest scavenging potency being observed for the hard texture cultivar with no effect of sprouting. These findings confirm the hypothesis that the phytochemicals of hard and soft wheat cultivars (sprouted or not) have different behavior during digestion in terms of biotransformation, bioaccessibility and ability to remove reactive species and indicate that tabbouleh produced from sprouted wheat results in increased release of bioactive phytochemicals during digestion.

Effect of micronization on olive pomace biotransformation in the static model of colonic fermentation.

The effect of granulometric fractionation and micronization of olive pomace (OP) on the biotransformation of phenolic compounds by intestinal microbiota was investigated in vitro. Three types of powdered OP samples were incubated with human feces to simulate colonic fermentation, after a sequential static digestion: non-fractionated OP (NF), granulometrically fractionated OP (GF) and granulometrically fractionated and micronized OP (GFM). GF and GFM favored the release of hydroxytyrosol, oleuropein aglycone, apigenin and phenolic acid metabolites in the first hours of colonic fermentation compared to NF (up to 41-fold higher). GFM caused higher release of hydroxytyrosol than GF. GFM was the only sample to release tyrosol and sustained tyrosol levels up to 24 h of fermentation. Micronization associated with granulometric fractionation was more efficient than granulometric fractionation alone to increase the release of phenolic compounds from the OP matrix during simulated colonic fermentation and can be further studied for nutraceutical purposes.

Natural deep eutectic solvent (NADES): A strategy to improve the bioavailability of blueberry phenolic compounds in a ready-to-use extract.

This study investigated whether a ready-to-use extract obtained using a natural deep eutectic solvent (NADES) affects the pharmacokinetic profile of blueberry phenolic compounds compared to organic solvent (SORG)-extracted compounds. SORG extract was administered as an aqueous solution after solvent removal. Wistar rats received a single dose of crude extract of blueberry obtained using NADES (CE-NADES) or SORG (CE-SORG), followed by LC-DAD-MS/MS analysis of blood and cecal feces. Non-compartmental pharmacokinetic analysis revealed that CE-NADES increased the bioavailability of anthocyanins by 140% compared to CE-SORG. CE-NADES increased the stability of phenolic compounds during in vitro digestion by delaying gastric chyme neutralization. These results suggest that besides being an eco-friendly solvent for the extraction of phytochemicals, choline chloride:glycerol:citric acid-based NADES can be used as a ready-to-use vehicle for increasing oral absorption of bioactive compounds such as anthocyanins.