Maximizing Contents of Phytochemicals Obtained from Dried Sour Cherries by Ultrasound-Assisted Extraction

Sour cherries were first dried by vacuum drying and then used as material for obtaining extracts rich in bioactive compounds by ultrasound-assisted extraction (UAE). The first step was to apply a factorial design for the preliminary experiments to determine the most influential UAE factors, and thus the three studied parameters were chosen as the most suitable for the design of the main experiment (temperature, liquid–solid ratio and ethanol concentration). In this part, the contents of total phenols and the total content of monomeric anthocyanins were taken for responses. For the further optimization of UAE, experimental design (face-centered) was applied, and the yield, total phenolics, flavonoid content and content of monomeric anthocyanins and antioxidant activity (DPPH, ABTS and FRAP assays) were analyzed. Temperature (40–80 °C), ethanol concentration (40–80%, w/w) and liquid–solid ratio (10–30 mL/g) were investigated as independent variables. The obtained experimental results were fitted to a second-order polynomial model and analysis of variance was used to determine the fit of the model and the optimal conditions for investigated responses. High quality extracts with high concentrations of polyphenols and anthocyanins were also obtained, which could be used as food additives.

Drying characteristics and product quality of whole blueberry pulp in vacuum drying process

A pilot-scale vacuum dryer with visualization system was used to study the drying characteristics of the whole blueberry pulp. The heating temperature, operating pressure and initial material thickness had significant effects on the drying characteristics and the retentions of total monomeric anthocyanins and vitamin C in dried blueberry powder (P < 0.05). According the heat transfer mode inside the material, the whole drying process could be divided into three periods: the boiling drying period, the convective drying period, and the conductive drying period. Most of water in the material was evaporated in the boiling and convective drying period. Considering the drying characteristics and dried product quality comprehensively, an optimal drying condition for whole blueberry pulp were: heating temperature 70 °C, operating pressure 1 kPa, and the initial material thickness 5 mm. It further compared the drying time, nutrients retention, hygroscopicity and microstructure of the product obtained by vacuum and vacuum freeze drying. The drying time of vacuum drying (1.2 h) was much shorter than that of vacuum freeze drying (44 h); the retentions of the total monomeric anthocyanins and vitamin C in dried blueberry powder of vacuum drying (67.9, 46.7%) were lower than that of vacuum freeze drying (79.0, 85.8%); while the hygroscopicity of vacuum dried powder was less than that of the freeze-dried product. The SEM images displayed that the surface of the vacuum-dried blueberry powder was porous, and the vacuum freeze-dried product was lamellar.

Phenolic Profiles of Red Wine Relate to Vascular Endothelial Benefits Mediated by SIRT1 and SIRT6

Dietary phenolic compounds possess potent bioactivity against inflammatory pathways of chronic inflammatory conditions, such as type 2 diabetes. Here, the phenolic profile and bioactivity of Italian red wines Gaglioppo, Magliocco, and Nerello Mascalese were characterized. NMR, HPLC/UV-Vis and spectrophotometric characterization showed that Magliocco was the richest wine in monomeric anthocyanins (two-fold), catechins, and low molecular weight phenolics (LMWP). A positive correlation was observed between the polyphenolic content and antioxidant capacity (p < 0.05), with Magliocco displaying the highest antioxidant capacity (p < 0.01). In vitro evidence on the endothelial cell models of insulin resistance and hyperglycemia showed the ability of Magliocco to reduce reactive oxygen species (ROS) (p < 0.01) and cytokine release (p < 0.01) and to upregulate SIRT1 and SIRT6 (p < 0.01). On the whole, the results indicated that the quantitative and qualitative phenolic profiles of red wines influence their in vitro beneficial effects on oxidative and proinflammatory milieu in endothelial cells, showing a positive modulation of SIRT1 and SIRT6, both implied in vascular aging.

Identification of Anthocyanins and Their Fouling Mechanisms during Non-Thermal Nanofiltration of Blueberry Aqueous Extracts

Organic fouling in the nanofiltration (NF) process, which is a non-thermal technology to recover active components, is a critical problem limiting its applications. This study seeks to identify the anthocyanins on the NF membrane and explore their fouling mechanisms during concentration of blueberry extracts. Seven kinds of monomeric anthocyanins in foulants—delphinidin-3-O-galactoside, delphinidin-3-O-glucoside, delphinidin-3-O-arabinoside, cyanidin-3-O-galactoside, petunidin-3-O-galactoside, peonidin-3-O-glucoside, and malvidin-3-O-glucoside—were identified. Moreover, chalcone, myricetin derivative, and an unknown substance with [M+H]+ at m/z 261.1309, which is the fragment ion corresponding to the break of glycoside bond of anthocyanins, were obtained. Interactions between anthocyanins and membrane made from polyamide were principally governed by the CH-π and π-π stacking of aromatic rings, the establishment of hydrogen bonds, and electrostatic interaction. This study will be helpful to further control fouling and choice of cleaning agents in concentration of anthocyanins-rich extracts.

A Mobile Analytical Device for On-Site Quantitation of Anthocyanins in Fruit Beverages

Anthocyanins are antioxidant and anti-inflammatory ingredients in various fruit beverages, for which their conservation and quantitation are important for the food industry. In this paper, we report a simple, portable device for accurate on-site determination of total monomeric anthocyanins in fruit beverages employing a Wi-Fi scanner coupled with a flexible microchip and a free mobile app. The detection principle is based on the pH-induced colorimetric reactions of anthocyanins performed in a specially designed microchip and validated with standard spectrophotometric measurements. The microchip with multiple testing vials was prepared with the benchtop molding method with a common PDMS elastomer and a transparency film; the photo of the scanned microchip is wirelessly sent to a smartphone and the RGB values of individual reaction vials in the microchip are analyzed with a free mobile app to determine the corresponding concentrations. It was demonstrated that the quantitation performance of this POCT device is comparable with conventional spectrophotometry in the determination of total anthocyanins in both standard solutions and fruit beverages.

Effect of Leaf Maceration and Withering Duration on Selected Tea Quality Parameters-A Case of Non-aerated Teas from TRFK 306 and TRFK 6/8 Clones

Leaf maceration and withering are processing steps that influence tea quality. The current study involved two tea clones, TRFK 306 and TRFK 6/8. Assessment was done on the effects of these steps on total monomeric anthocyanins (TMA), total soluble solids (TSS) and the tasters’ comments. The tea leaves were processed by orthodox (rolling) and Cut, Tear and Curl (CTC) manufacture methods and withered at an interval of 5 hours. TMA were assayed following Giusti and Wrolstad protocol while TSS was determined by weight differential method. Experienced tea tasters participated in the sensory exercise. Data was subjected to general linear model using SAS package version 9.1.3. Both CTC and orthodox non-withered teas had 93 mg/L residual anthocyanins while long withered teas had lower levels averaging 24 mg/L. TRFK 306 non-withered orthodox and CTC teas had 3.2 mg/ mL and 3.43 mg/mL TSS, respectively, while those withered for 20 hours and processed by both methods had 3.5 mg/mL and 3.23 mg/mL TSS, respectively. TRFK 6/8 none withered orthodox and CTC teas had 4.29 mg/mL and 3.62 mg/mL TSS, respectively while those withered for 20 hours had 3.62 mg/mL and 3.51 mg/mL TSS, respectively. The colour score for non-withered TRFK 306 orthodox and TRFK 6/8 teas was 3.33 and 3.00 respectively, while teas withered for 20 hours from both clones had 4.00 and 3.67 colour scores. It was established that leaf maceration style does not affect TMA and long withering duration reduces the levels of anthocyanins. TRFK 6/8 had more TSS than TRFK 306 irrespective of processing method. Rolling and withering improves the liquor colour of teas.

Delphinidin-3-O-sambubioside: a novel xanthine oxidase inhibitor identified from natural anthocyanins

Objectives This study was conducted to investigate the xanthine oxidase (XO) inhibitory activities of 18 monomeric anthocyanins from berry fruits and roselle, and to illustrate the underlying mechanism of the most active anthocyanin delphinidin-3-O-sambubioside. Materials and Methods 18 monomeric anthocyanins were prepared and purified in our lab. The inhibitory properties of anthocyanins were investigated by in vitro inhibitory activity studies and fluorescence quenching studies; the inhibitory mechanism were explored through kinetic studies, fluorescence quenching studies, circular dichroism analysis and computational docking simulations. Results XO inhibitory activities of anthocyanins were related to the structures of B rings and glycosides. Among all the tested anthocyanins, delphinidin-3-O-sambubioside showed the most potent inhibitory activity with an IC50 of 17.1 μM, which was comparable to the positive control allopurinol. Spectroscopic results revealed that delphinidin-3-O-sambubiosid could spontaneously interact with XO and induce conformational changes. Computational docking study indicated that delphinidin-3-O-sambubioside could bind to XO with a proper orientation, stably formed π-π interactions and hydrogen bonds with key residues, thus preventing the substrate from entering the active pocket. Conclusions In brief, our study identified delphinidin-3-O-sambubioside as a potent XO inhibitor from natural anthocyanins, which is potentially applicable for prevention and treatment of hyperuricemia.

Characterization of Anthocyanins and Anthocyanin-Derivatives in Red Wines during Ageing in Custom Oxygenation Oak Wood Barrels

The ageing of wines in oak barrels is a key stage in the production of high-quality red wines, with the type of oak chosen and the amount of oxygen received by the wine being the determining factors of the process. This work analyses the effect of ageing the same red wine in barrels with different oxygenation rates for one year (OTR), specifically the effect on the evolution of anthocyanins, their derivatives and the appearance of new pigments according to the oxygen dosage in barrels. Results show that wines aged in High-Wood-OTR barrels have a large quantity of monomeric anthocyanins and wine aged in Low-Wood-OTR barrels presents a major intensity of colour. Moreover, using LC-MS analysis, it was possible to detect and identify different families of anthocyanin derivatives, including the tentative identification of two new aldehyde-flavanol-methylpyranoanthocyanin pigments.

Rootstock and harvest season affect the chemical composition and sensory analysis of grapes and wines of the Alicante Bouschet (Vitis vinifera L.) grown in a tropical semi-arid climate in Brazil

Aim: In this study, we aimed to evaluate the composition of grapes and wines of the Alicante Bouschet variety from a tropical semi-arid area in Brazil, by studying two rootstocks and harvests in different semesters (climates) of the same year.Methods, Results: Vines of Vitis vinifera L., Alicante Bouschet, a teinturier variety, were grown in a tropical semi-arid climate in Brazil. The phenolic composition of the grapes and wines was measured to assess how they had been affected by two rootstocks (IAC 572 and 1103P) and two harvest seasons, Semester 1 and Semester 2 (in this region, a grapevine produces two harvests per year, with an intra-annual climate variability). The grapes and wines were subjected to the usual physicochemical analyses, as well as to spectrophotometric and chromatographic analyses. Sensory analysis was carried out by professional tasters. The results show that there is a rootstock effect and a harvest season effect for several parameters on grape composition, as well as on the resulting wines. The grapes from vines grafted onto IAC 572 rootstock contained higher titratable acidity, tartaric acid, malic acid, total anthocyanins, total proanthocyanidins in skins and seeds and polymeric tannins in skins. The grapes from vines grafted onto 1103P rootstock contained higher concentrations of total phenols and non-flavonoids, total monomeric anthocyanins, monomeric and polymeric tannins in the seeds. The second semester wines were higher in total anthocyanins, total phenols, flavonoids and non-flavonoids, condensed tannins and low molecular weight flavanols, astringency potential, colour intensity, titratable acidity, total dry extract and alcohol content.Conclusions: The results demonstrate an influence of rootstock and harvest season (semester/climate) on grape and wine composition. Some of the grape and wine phenolic compounds analysed individually (some monomeric anthocyanins and low molecular weight flavanols) were higher in the first semester than in the second. The overall phenolic parameters determined in grapes and wines from the second semester were higher than those from the first. According to the sensory analyses, the semester (climate) effect was stronger than the rootstock effect, and the wines from the second semester received the highest scoring than those from the first semester, mainly for olfactory and gustatory attributes.Significance and impact of the study: This study uses a holistic methodology, mainly with respect to the phenolic compounds, to examine the combined effects of rootstocks and intra-annual climate variability on grape and wine composition. The results of this study may contribute to future research, as well as help the producers and wine companies of tropical regions to tailor viticultural and oenological parameters, in order to improve the quality and typicality of the products.

Assessment of Bioactive Phenolic Compounds and Antioxidant Activity of Blackberry Wines

Blackberry wine is a natural source of bioactive phenolic compounds that have profound antioxidant potential. The objectives of the present research were to assess the phenolic compounds and antioxidant activity of blackberry wines (BW), and to use the chemometric analysis to differentiate among the two groups of samples, i.e., conventional and organic. Fifteen BW samples were analyzed for their total polyphenol index, total polyphenols, total flavonoids, total tannins, total monomeric anthocyanins and antioxidant activity by the appropriate spectrophotometric methods. The concentrations of individual phenolic acids (gallic acid, chlorogenic acid, caffeic acid, p-coumaric acid and cinnamic acid) and trans-resveratrol were determined by high-performance liquid chromatography. A comparison between the two groups of investigated BW samples revealed a statistically significant difference in the concentration of caffeic acid and p-coumaric acid, both being higher in the organic BW samples. Furthermore, the results showed a series of statistically highly significant relationships between the analyzed constituents (caffeic acid and p-coumaric acid). The antioxidant activity of the investigated wines was proportional to the concentrations of bioactive phytochemicals.