Anthocyanin Content Of Extracts Research Articles

Combined effect of harvest time and postharvest dehydration length on the composition of withered grapes for Sforzato di Valtellina DOCG wine production.

Sforzato di Valtellina (Sfursat) is a PDO reinforced red wine produced in Valtellina (northern Italy) from partially withered red grapes (Vitis vinifera L.) cv. Nebbiolo. The present study aimed to evaluate the combined influence of different grape ripeness levels and withering length on the chemical composition, mechanical properties, and phenolic profile of Nebbiolo winegrapes from two Valtellina vineyards. During three consecutive vintages (2019, 2020, and 2021), three different technological binomials have been tested: early harvest/long withering (EL), medium-term harvest/medium-term withering (MM), and late harvest/short withering (LS). At the end of the withering process, EL thesis usually presented the highest values of sugars and acidity. Extractable seed polyphenols showed a decreasing trend by leaving the grapes on the plant longer, and this effect increased considerably after withering with respect to fresh samples. EL and MM evidenced the greater concentration of these compounds expressed on grape weight, particularly for tannins. Instead, skin-extracted total phenolics were less influenced by the harvest time, whereas their concentration increased after withering. The harvest time appears to have a higher impact than the withering length on the final extractable anthocyanin content, although the trend was no stable during the vintages or common for the two vineyards evaluated. EL and MM experienced the highest contents of grape skin tannins in most cases, suggesting that a longer withering increases their concentration. Harvest time and withering length can be modulated according to the desired oenological objective, promoting the valorization of grape potentialities. The choice to harvest the grapes earlier and enhance the withering length should be preferred to obtain wines with higher acidity and phenolic content, more suitable for long-ageing period. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of natural clinoptilolite on physiology, water stress, sugar, and anthocyanin content in Sanforte (Vitis viniferaL.) young vineyard

AbstractIn the Mediterranea area, major effects of climate change are a modification in rainfall patterns, an increase in temperature with an intensify in tropical nights, and an increase in incoming radiations, especially UV-Bs. Despite the various adaptation strategies, grapevines are sensitive to altered climatic conditions. This paper aims to assess the benefits of applying a new sustainable product to the soil that can implement farmers’ resources to adapt to this changing situation. Zeowine was realized by combining the properties of zeolite, which has excellent potential in many sectors such as in agriculture, with the organic substance of a compost obtained on a company scale from the reuse of waste processing grapes, pomace and stalks. The effects of two different soil management (Z – Zeowine, 30 t/ha dose and C – Compost, 20 t/ha dose) on vine physiology and berry compositions in Sanforte grapevines (new plantation) were studied during the 2019–2020–2021 growing seasons in the San Miniato area, Italy. The following physiological parameters of grapevines were measured: leaf gas exchange, leaf temperature, stem water potential and chlorophyll fluorescence. The results showed that Z increased single leaf photosynthesis, reduced leaf temperature and water stress. In addition, phenolic and technological parameters were studied. The Z-treated vines had higher sugar content and total and extractable anthocyanin content as well as berry weight. These results suggested that the application of zeolites added to compost in the vineyard to the soil can be a valid tool to mitigate the effects of climate change.

Aroma composition of Tempranillo grapes as affected by iron deficiency chlorosis and vine water status

Water deficit and iron nutritional deficiency (iron chlorosis) are frequent environmental stresses affecting grapevine production in the Mediterranean region. The objectives of this work were (i) to study the combined effects of both stresses on aromatic profile of Tempranillo grapes, occurring simultaneously in the vineyard, and (ii) to evaluate the viability of foliar chlorophyll content at veraison (Chl) to early assess aromatic quality potential of grapes in those conditions. Twenty non-irrigated vineyard subzones (10 m × 10 m each), affected and non-affected by iron chlorosis, were monitored in Ribera del Duero Appellation of Origin (North-Central Spain) during two consecutive seasons. Factorial ANOVA was performed to study the effects of predawn leaf water potential and Chl measured at veraison on the must composition parameters and, specifically, on the concentrations of free and bound aromatic compounds. Water deficit tended to increase color intensity and extractable anthocyanin content of the grapes, whereas the incidence of iron deficiency enhanced total phenolic compound content within subzones with better water status. More water or iron stressed subzones restricted C6-alcohols contents than less stressed subzones. Without significant effects on vine vigor, yield or berry size, the incidence of iron chlorosis increased the concentrations of some specific terpenes, C13-norisoprenoids, volatile acids and volatile phenols. These results showed that low to moderate iron stress can have positive effects on grape aromatic quality, and demonstrated that Chl can be a useful tool in precision viticulture to map the aromatic potential within rainfed vineyards affected by iron chlorosis.

Phenolic compounds extraction in enzymatic macerations of grape skins identified as low-level extractable total anthocyanin content.

Anthocyanins in wine principally depend on grape skin extractable anthocyanin content, that is, the amount of anthocyanins present in grape skin that are released to wine during the maceration stage. This amount of extractable anthocyanins is closely linked to the cell wall degradation of skin cells. Indeed, among other methodologies, the maceration in presence of different enzymes can be used to increase cell wall degradation, and therefore, the amount of anthocyanins extracted from grape skins to wine. Vitis vinifera L. cv. Tempranillo and Syrah red grapes have been identified as samples with low anthocyanin extraction potential by near infrared hyperspectral imaging. Grape skins have been macerated in the presence of cellulase, glucosidase, and pectinase. Then, color of the supernatants and phenolic compounds extracted from grape skins (total phenols, total flavanols, and total and individual anthocyanins) has been determined. Cellulase and glucosidase have shown a positive effect in the extraction of phenolic compounds from these grapes. Macerations carried out in the presence of cellulase have produced supernatants with a more intense color (lower lightness and higher chroma values), and a higher extraction of flavanols and anthocyanins than the respective control essays. However, pectinase treatments have produced the opposite effect, which could be partially explained by an eventual interaction between the cell wall polysaccharides liberated by pectinase and the phenolic compounds extracted. Synergy effects do not appear between cellulase and glucosidase. Moreover, the negative effect of the addition of pectinase might be due to the interactions between the cell wall material liberated by pectinase and the phenolic compounds extracted. PRACTICAL APPLICATION: In the present study, grape samples with a low anthocyanin extraction potential have been identified, and these samples have been macerated in the presence of different enzymes. The applied enzymes were three of the most common enzymes that are applied in the wine industry. Individual enzymes and mixtures have been applied to Syrah and Tempranillo grape skin samples and the results have been compared to control macerations. Knowledge in this topic will help the production of quality wines.

Combined effects of water status and iron deficiency chlorosis on grape composition in non-irrigated vineyards

ABSTRACT: Although water deficit and iron deficiency chlorosis are common environmental stresses in the Mediterranean area, few data are reported in the literature on their effects on vineyards, when acting simultaneously. The main objective of this research was to study the combined effects of iron deficiency and water status on vigor, yield and fruit composition in rainfed vineyards. Moreover, the investigation aimed to evaluate the feasibility of using foliar chlorophyll content (Chl) and predawn leaf water potential (LWP), measured at veraison, to assess potential quality of grapes in the framework of precision viticulture. For this, 24 non-irrigated ‘Tempranillo’ vineyard subzones were monitored in Ribera del Duero (North-Central Spain) during three consecutive seasons (2011-2013). The analysis of variance and principal component analysis showed that malic acid concentrations of the must were impacted only by Chl, whereas total soluble solids and total acidity were mainly modified by LWP. Both water and iron status reduced yield and berry weight and had additive effects on extractable anthocyanin content in grapes, total polyphenol index and color density of the must. In all seasons, the ratio Chl/LWP had a better predicting value for quality parameters of these grapes than leaf area index, Chl or LWP individually. The present work demonstrates the potential interest of physiological indexes combining water status and foliar chlorosis as indicators of grape phenolic potential in rainfed vineyards affected by iron deficiency.

Hawthorn berries extract for the green synthesis of copper and silver nanoparticles

Silver and copper nanoparticles (AgNPs and CuNPs) have attracted worldwide attention due to their unique antimicrobial properties. Ethanol and water extracts of hawthorn fruit were chosen to prepare AgNPs and CuNPs. The effects of the pH, contact time, temperature of the solution, type of precursor of metal ions and type of hawthorn extract on the size distribution of particles were studied. The monodispersed and stable AgNPs and CuNPs were prepared with an average size of 60 nm and 200 nm, respectively. Total phenolic content and the anthocyanin content of extracts were determined. The antimicrobial activities of AgNPs and CuNPs were carried out with a series of microbial assays.

Effect of novel drying techniques on the extraction of anthocyanins from bilberry press cake using supercritical carbon dioxide

Abstract The objective of this study was to assess the effect of novel drying techniques on the total anthocyanin content of extracts from bilberry press cake using supercritical carbon dioxide with ethanol as co-solvent. Prior to extraction, bilberry press cake was dried at 40 °C and 70 °C to moisture contents of 6% and 20% (w/w) by infrared drying, infrared impingement drying, and microwave-assisted hot-air drying and compared to freeze drying. The total anthocyanin content of extracts varied in the range of 13.67 ± 0.25 mg/g dry weight to 43.66 ± 0.79 mg/g dry weight, dependent on the choice of drying technique, temperature, and moisture content. Bilberry press cake treated with infrared impingement drying at 70 °C to 20% (w/w) moisture content resulted in the highest total anthocyanin content of extracts. The findings of this study show the importance in combining supercritical carbon dioxide extraction with an appropriate drying technique. Industrial relevance Supercritical carbon dioxide extraction is a green technology that offers mild extraction conditions for sensitive compounds. Drying prior to the extraction is usually necessary and may limit the extraction efficiency by degrading sensitive compounds or influencing the matrix and thereby the release of solute in the subsequent extraction step. More knowledge about the effect of different drying techniques on the extraction efficiency is of industrial interest to optimize both the yield and quality of extracts.

Use of near infrared hyperspectral tools for the screening of extractable polyphenols in red grape skins

Hyperspectral images of intact grapes were recorded at harvest time using a near infrared hyperspectral imaging system (900–1700nm). Spectral data have been correlated with red grape skin extractable polyphenols (total phenolic, anthocyanins and flavanols) by modified partial least squares regression (MPLS) using a number of spectral pretreatments. The obtained results (coefficient of determination (RSQ) and standard error of prediction (SEP), respectively) for the developed models were: 0.82 and 0.92mgg−1 of grape skin for extractable total phenolic content, 0.79 and 0.63mgg−1 of grape skin for extractable anthocyanin content, 0.82 and 0.45mgg−1 of grape skin for extractable flavanol content. The obtained results present a good potential for a fast and reasonably inexpensive screening of the extractable polyphenolic compounds in intact grapes. Moreover, the heterogeneity of extractable polyphenols within the ripeness stage has been also evaluated using the proposed method.

Characterization of Hydrangea macrophylla Cultivars by the Anthocyanin Content in their Sepals

Abstract In order to ascertain the role of anthocyanin content on the color and brightness of Hydrangea macrophylla sepals, anthocyanin contents of different colored sepals were measured for numerous commercial cultivars. Anthocyanin contents were primarily determined by extraction of the pigment, then measurement by differential spectrophotometry. Concentrations ranged from about 25 to over 400 μg delphinidin-3-glucoside per g of fresh sepal, with the magnitude roughly proportional to the perceived intensity of sepal coloration for that Hydrangea macrophylla cultivar. However, the anthocyanin content was independent of the sepal color, being the same for red, purple, or blue sepals of the same cultivar. Even though significant sepal-to-sepal variation in color intensity existed within a single inflorescence, the extractable anthocyanin content was constant for a specific cultivar. Accordingly, Hydrangea macrophylla cultivars were classified in terms of their color brightness or anthocyanin content in sepals as blush (very light colored, 25 to 60 μg·g−1), cold-hardy (light colored, 80 to 120 μg·g−1), classic (medium colored, 140 to 190 μg·g−1), vivid (deep colored, 230 to 270 μg·g−1), or vibrant (very deep colored, >300 μg·g−1) at peak bloom. The anthocyanin content of the sepals steadily increased as the inflorescence approached peak bloom, remained constant for a week or more, then decreased. The cultivar-dependent anthocyanin contents of the sepals can be used, in part, to rationalize the relative bluing capability of the various Hydrangea macrophylla cultivars.

Nondestructive Estimation of Anthocyanin Content in Autumn Sugar Maple Leaves

A field-portable tool for nondestructive foliar anthocyanin content estimation would be beneficial to researchers in many areas of plant science. An existing commercial chlorophyll content meter was modified to measure an index of anthocyanin content. The ability of the experimental anthocyanin meter (ACM) to estimate total extractable anthocyanin content was tested in sugar maple (Acer saccharum Marsh.) leaves representing several subjective color categories collected from a variety of field sites in northwestern Vermont on several dates in Autumn 2003. Overall, there was a significant linear relationship between anthocyanin content index (ACI) and total extractable anthocyanin content (r2 = 0.872, P < 0.001). Therefore, the ACM appears to be an effective tool for estimation of relative anthocyanin content in large samples of autumn sugar maple leaves.

Effect of altitude on the wine-making potential of Listán negro and Ruby Cabernet cultivars in the south of Tenerife island

<p style="text-align: justify;">In the south of the island of Tenerife (Valle de Güimar), a study was made of the composition of the grape and fundamentally in colour potential during the ripening of the red varieties Listán negro and Ruby Cabernet in two vineyards located at different heights above sea level. The conventional ripening parameters and total and extractable anthocyanin content have been determined in order to estimate all the main characteristic phenolic. Significant differences were detected between the varieties, along with a clear influence of vineyard altitude on accumulation of colour and phenolic substances in the grapes.</p>

Relationship between Fruit Size and Extractable Anthocyanin Content in Cranberry

Abstract The relationship between fruit size and extractable anthocyanins was investigated in 6 cranberry (Vaccinium macrocarpon Ait.) cultivars: Franklin, Ben Lear, Early Black, Crowley, Stevens, and Pilgrim. Extractable anthocyanins decreased linearly as fruit size, measured by fruit weight, of the sample increased. The relationship was especially apparent for dark-colored cultivars and the dark-colored berries within a cultivar. Results suggest that fruit size can contribute to the disparity between fruit color and extractable anthocyanins, and selection for larger-berried genotypes to increase yields may, concommitantly, reduce anthocyanin yield.