A green analytical method for the determination of polyphenols in wine by dispersive pipette extraction and LC-MS/MS.

A simple sample preparation approach employing the dispersive pipette extraction (DPX) technique is proposed to determine twelve polyphenols, including phenolic acids and flavonoids in wines, followed by identification and quantification by LC-MS/MS. The extraction parameters, including sample volume and pH, salting out effect, time and cycles of extraction and desorption, and desorption solvent were optimized using univariate and multivariate designs. The analytical performance was satisfactory, with determination coefficients greater than or equal to 0.9877, precisions with values lower than 20 %, and recoveries ranging from 87 to 114 %. The applicability of the method was evaluated in red wine. The major compounds determined in the sample were (-)-epicatechin (23.5 mg L-1), (+)-catechin (19.2 mg L-1), and myricetin (14.6 mg L-1). The green character of the analytical procedure and the sample preparation step were evaluated by three analytical metrics.

Dairy powder enriched with a soy extract (Glycine max): Physicochemical and polyphenolic characteristics, physical and rehydration properties and multielement composition.

This work presents the enrichment of powdered dairy compounds with soy extract, and the determination of its physical properties, rehydration characteristics, multielement profile, and polyphenolic potential. Five dairy compound formulations were developed, where milk powder was replaced by 10, 20, 30, 40, and 49 % w/w of soy extract.. Multivariate analyzes using combined PCA analyzes were used to group the samples and, thus, reveal the main characteristics associated with their physicochemical properties, bioactive composition, and multi-element profile. The protein content in the samples was not significantly affected by the addition of soy extract. There was a gradual increase in the total fat as the concentration of soy extract increased. Furthermore, with the increase in the percentage of soy extract in the dairy compounds, there was an increase in the levels of total polyphenols, total flavonols, and antioxidant capacity, and of some minerals, such as Fe, Mn, P, Cu, and Mg. The DC49 sample showed the highest values for total polyphenols (178.65 mg of gallic acid (GAE)/100 g) and total flavonols (1.51 mg of catechin/100 g). The addition of soy extract promoted the enrichment of important minerals in the samples, with an increase of up to 55 times in the Fe content and up to 40 times in the Mn content. Physical properties (density and fluidity) and rehydration properties (wetting, dispersibility, and solubility) also were affected as the percentage of soy extract in the samples increased. When there was an addition of up to 20 % soy extract, the samples are still wettable. All dairy compounds showed solubility above 69 %. The use of soy extract in the polyphenolic and mineral enrichment of the dairy compounds is important to add nutritional value to powdered milk, we emphasize that this product has enormous potential to be used in diets that require mineral supplementation.

Phytochemicals, Monosaccharides and Elemental Composition of the Non-Pomace Constituent of Organic and Conventional Grape Juices (Vitis labrusca L.): Effect of Drying on the Bioactive Content.

Grape and grape derivatives contain a variety of antioxidants that have gain increasing interest for functional foods applications. The chemical composition of grapes is mainly related to grape variety and cultivation factors, and each grape constituent exhib its unique characteristics regarding its bioactive properties. This study investigated the chemical composition and the effect of drying on the bioactive content of the non-pomace constituent obtained in the processing of organic and conventional grape juices from V. labrusca L. The non-pomace samples were analyzed for polyphenols, monosaccharides, antioxidant activity and elemental composition and the effect of drying on the bioactive composition was evaluated in samples subjected to lyophilization and drying with air circulation. The analyses revealed high concentrations of proanthocyanidins, flavanols and anthocyanins, and high antioxidant capacity of the organic and conventional samples. The drying processes reduced significantly (P < 0.05) the total phenolic content that ranged from 13.23 to 36.36 g/kg. Glucose, xylose, and mannose were the predominant monosaccharides, whereas K, Ca and Mg were the most abundant minerals. Variations in the chemical composition of organic and conventional samples were associated with cultivation factors. Nevertheless, this non-pomace constituent is a promising source of nutrients and polyphenols with bioactive potential.