Dendrimers as Color-Stabilizers of Pyranoanthocyanins: The Dye Concentration Governs the Host-Guest Interaction Mechanisms

Natural deep eutectic solvents (NADES)-Extracted Anthocyanins: Bioaccessibility in electrospun PEO microfibers

Anthocyanins extracted with deep eutectic solvent (NADES) (chlorine-chloride: xylitol, 5:2) were used to produce polyethylene oxide (PEO) composites through electrospinning technique, analyzing their microscopic and physical characteristics. The coated anthocyanins were then subjected to in vitro gastrointestinal digestion to evaluate their bioaccessibility compared to lyophilized jussara pulp. The remaining total anthocyanin content (TAC) after intestinal in vitro digestion did not change significantly among the assessed samples, and both showed around 30% recovery. The TAC recovery after the gastric phase, on the other hand, showed a major difference (70.84% vs. 48.13%), revealing that the composites fabricated by the electrospinning technique can significantly maintain anthocyanins NADES-extracted stability during the gastric phase of digestion, potentially allowing better absorption trough stomach wall. The results can be considered a first step to applying anthocyanins-encapsulated in foodstuff as a natural pigment.

Retention of Phthalates in Wine Using Nanomaterials as Chemically Modified Clays with H20, H30, H40 Boltron Dendrimers

The presence of phthalic acid esters in wines presents a major risk to human health due to their very toxic metabolism. In this paper, aluminosilicate materials were used, with the aim of retaining various pollutants and unwanted compounds in wine. The pollutants tested were di-butyl and di-ethyl hexyl phthalates. They were tested and detected using the gas chromatography-mass spectrometry (CG-MS) analytical technique. Nanomaterials were prepared using sodium bentonite, and were chemically modified via impregnation using three types of Boltron dendrimers of second, third and fourth generations (NBtH20, NBtH30 and NBtH40). The synthesized nanomaterials were characterized using the Brunauer-Emmett-Teller (BET) method, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. In this paper, two aspects were addressed: the first related to the retention of phthalate-type pollutants (phthalic acid esters-PAEs) and the second related to the protein and polyphenol levels in the white wine of the Aligoté grape variety. The results obtained in this study have a major impact on PAEs in wine, especially after treatment with NBtH30 and NBtH40 (volumes of 250-500 μL/10 mL wine), with the retention of the pollutants being up to 85%.

pH-regulated interaction modes between cyanidin-3-glucoside and phenylboronic acid-modified alginate

Stabilizing mechanisms through covalent and non-covalent interactions have been studied along the years for color stabilization of anthocyanin dyes. In this work, the chemical functionalization of a natural and biocompatible marine-based polysaccharide (alginic acid) with 3-aminophenylboronic acid via carbodiimide coupling chemistry was carried out in order to create a bifunctional material for pH-dependent selective interaction with colored cyanidin-3-glucoside chemical species. The interaction studies were performed by UV-Vis, ¹H, and ¹¹B NMR spectroscopy. Overall, the apparent acidic and hydration constants are more stabilized in the presence of phenylboronic acid-modified alginate. For more acidic pH values the red cationic flavylium cation of cyanidin-3-glucoside mainly interacts through non-covalent electrostatic interactions with the carboxylate groups of the biopolymer derivative with association constant around 0.5 mM^-1 while at higher pH values boronate-catechol covalent bonds are favored, promoting the stabilization of the colored neutral and anionic quinoidal bases of anthocyanins instead of colorless hemiketal and chalcones.