Phenolic compounds profile and antioxidant activity of commercial tropical red wines (Vitis viniferaL.) from São Francisco Valley, Brazil

An improved method for determining free amino acids by RP-HPLC/DAD with o-phthalaldehyde derivatization: Method evaluation in beers and wines

Rapid methods for amino acid determination are desired to reduce running times, and the main factors involved in the rapid separation of these compounds in HPLC are the columns, solvents, and gradient. The present study refers to a method optimization to rapidly analyze 19 amino acids in RP-HPLC/DAD with pre-column derivatization using o-phthalaldehyde. To evaluate the method's robustness, Indian Pale Ale-IPA beers and wines from the San Francisco Valley-SFV and Chapada Diamantina-CHD, Brazil, were analyzed. The method showed acceptable linearity (R2 > 0.992), precision (CV < 3.96%), recovery (74.2-113%), detection limits (<0.56 mg/L), and quantification limits (<3.62 mg/L) and separation gradient in 18.5 min. IPA beers were discriminated from wines by arginine, asparagine, tryptophan, alanine, phenylalanine, and tyrosine contents. Furthermore, CHD wines were discriminated from SFV wines by asparagine, glutamine, arginine, cystine, tyrosine, and leucine. In conclusion, a rapid method for amino acid determination was optimized and validated for wines and beers.

Wheat craft beer made from AFB1-contaminated wheat malt contains detectable mycotoxins, retains quality attributes, but differs in some fermentation metabolites

Levels of aflatoxin B1 (AFB1) were measured during the production of wheat craft beer made with wheat malt contaminated with AFB1 (1.23 µg/kg). A wheat craft beer made with non-contaminated wheat malt was produced for comparison purposes. AFB1 was measured after mashing (malt after the mashing process), and in spent grain (spent grains are filtered to collect the wort - remaining sugar-rich liquid), sweet wort, green beer, spent yeast, and in beer. Physicochemical parameters (pH, titratable acidity, color parameters, total soluble solids), sugars, organic acids, alcohols, and phenolics were evaluated after mashing, and in sweet wort, green beer, and beer samples. Density and yeast counts were determined over 120 h of sweet wort fermentation every 24 h. The AFB1 levels in the final beer were 0.22 µg/L, while the spent grains and spent yeasts contained 0.71 ± 0.17 and 0.11 ± 0.03 µg/kg of AFB1, respectively. AFB1 contamination did not influence the final product's physicochemical parameters, density during fermentation, fructose, or glycerol content. Higher yeast counts were observed during the first 48 h of non-contaminated wheat craft beer fermentation, with higher ethanol, citric acid, and propionic acid contents and lower glucose, malic acid, and lactic acid contents compared with beer contaminated with AFB1. Non-contaminated wheat craft beer also had higher concentrations of gallic acid, chlorogenic acid, catechin, procyanidin A2, and procyanidin B1. AFB1 contamination of wheat malt may not affect basic quality parameters in wheat craft beer but can influence the final product's organic acid and phenolic contents. Our findings show that if wheat craft beer is made with contaminated malt, AFB1 can remain in the final product and may pose a risk to consumers.

Chemometric analysis for authentication of 'Syrah' and 'Tempranillo' red wines of San Francisco Valley-Brazil compared to wines from other world regions by the molecular profile in HPLC

The aim of this study was to evaluate the phenolic composition, sugars, and organic acids by HPLC-DAD/RID, and the antioxidant capacity of 100% commercial 'Syrah' and 'Tempranillo' red wines from the San Francisco Valley-SFV wineries, and to compare them with commercial monovarietal wines of the same cultivars from countries such as South Africa, Spain, Chile, and Australia. In total, 25 phenolic compounds were quantified and classified into chemical groups in all wines (phenolics acids, flavanones, flavan-3-ols, flavonols, anthocyanins, and stilbenes). Among these, catechin, procyanidins B1 and B2, lactic acid, and antioxidant capacity were highlighted as the markers responsible for the typification of SFV wines when compared to wines from temperate regions. The data reported here contribute to the knowledge of the potential for producing quality wines in tropical climate regions. The wines of cultivars 'Syrah' and 'Tempranillo' are consolidated among the wineries in the SFV region, Brazil, due to their excellent adaptation to the semi-arid tropical climate. The SFV recently applied for a wine geographical indication as its wines are young with tropical climate typicity. This study shows that it is possible to differentiate SFV Syrah and Tempranillo wines from other world regions by HPLC molecular profile using chemometric techniques.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05739-7.

Effect of Winemaking on Phenolic Compounds and Antioxidant Activities of Msalais Wine

Msalais wine (MW) is a popular traditional wine with the cultural characteristics of a specific Chinese ethnic group. In this study, phenolic profiles and antioxidant characteristics were identified using chromatographic analysis. A total of thirty-eight compounds, including eight furans, eleven phenolic acids, fourteen flavonoids, and five others, were identified via LC-MS/QTOF. It was found that catechin is the most abundant phenolic compound in MW, followed by epicatechin, gallic acid, caffeic acid, rutin, and p-coumaric acid. Winemaking had a significant influence on the levels of phenols and antioxidant activity. Condensed juice (CJ) displayed the highest phenol and antioxidant activity levels, while the levels were significantly decreased during the fermentation process and gradually stabilized thereafter during the aging process. A correlation analysis between the polyphenols in Msalais and their antioxidant capacity was performed to determine which molecules contributed more to the antioxidant capacity in a complex mixture of polyphenols. All of the phenolic compounds, except ferulic acid, showed good correlation with DPPH, ABTS, and CUPRAC. Among them, resveratrol had the strongest antioxidant capacity, although its concentration was very low. Catechin also had a strong antioxidant capacity, which was positively correlated with its concentration. This indicates that the antioxidant activity of Msalais is related to the number, type, and structure of polyphenols.

Chemical typicity of tropical tannat red wines from sub-middle São Francisco Valley, Brazil

Tannat is a Vitis vinifera cultivar with typically high phenolic compound contents, showing intense coloration, well-bodied, and great aging potential. However, even with this great potential, this variety is still commercially underexplored in the Sub-middle São Francisco Valley (SSFV). This work aimed to characterize the typicity of Tannat red wines from Sub-middle São Francisco Valley (SSFV), Brazil. In addition, the present work represents the first study featuring phenolic compounds quantification and antioxidant activity of Tannat in tropical climate wine-producing regions. Considering the condition of a short-applied maceration time during the winemaking, the tropical Tannat wine showed significant antioxidant activity and high phenolic contents. Trans-caftaric, malvidin-3-O-glucoside, and procyanidin B1 stood out among the phenolic compounds quantified, presenting Tannat with the potential to be an important grape variety to tropical wine-producing regions in Brazil, containing high contents of bioactive compounds. Previously results to compounds (-)-epigallocatechin gallate, procyanidin B2, quercetin-3-β-D-glucoside, pelargonidin-3-O-glucoside, chlorogenic acid, and piceatannol were not found in Tannat wines. Further studies are necessary to make the Tannat grape's adaptation better in tropical climate conditions, including investigating the phenolic profile and antioxidant activity of Tannat red wines with longer maceration times during the winemaking.

Graphical abstract

Wine phenolic profile altered by yeast: Mechanisms and influences

Grape phenolic compounds undergo various types of transformations during winemaking under the influences of yeasts, which further impacts the sensory attributes, thus the quality of wine. Understanding the roles of yeasts in phenolics transformation is important for controlling wine quality through fermentation culture selection. This literature review discusses the mechanisms of how yeasts alter the phenolic compounds during winemaking, summarizes the effects of Saccharomyces cerevisiae and non-Saccharomyces yeasts on the content and composition of phenolics in wine, and highlights the influences of mixed cultural fermentation on the phenolic profile of wine. Collectively, this paper aims to provide a deeper understanding on yeast-phenolics interactions and to identify the current literature gaps for future research.

Oenological potential and health benefits of Chinese non-Vitis vinifera species: An opportunity to the revalorization and to breed new varieties

The wine industry is focused on the producing wine mostly from European grapevine varieties (Vitis vinifera L.). China has experienced a significant growth of the vineyard surface, based on the cultivation of these grapevine varieties. Currently, China has become one of the countries with the largest surface of planted vineyards in the world. In the last years, there has been a trend to oenologically and viticulturally revalorize certain autochthonous grapevine species. China holds a great diversity of Vitis species, which are being the focus of study. This could be an important alternative for the diversification of wine production, providing new products with a strong identity. Additionally, the varietal homogenization has increased the vineyard genetic vulnerability in relation to the emergence of grapevine diseases and their resistance to chemical fungicides. In this way, non-Vitis vinifera species are characterized by having a high resistance to a wide range of biotic and abiotic factors, which can bring an opportunity to breed new varieties. However, there is little available information about the oenological potential of these species, which makes it a current interesting topic. Therefore, this review aims to summarize the oenological potential of non-Vitis vinifera species found in China, discussing their potential effects on human health and thus, to propose some Chinese wild grapes for their use in breeding programs.

Determining 1-kestose, nystose and raffinose oligosaccharides in grape juices and wines using HPLC: method validation and characterization of products from Northeast Brazil

The objective of this work was to validate a method for direct determination in grape juice and wine of 1-kestose, nystose and raffinose oligosaccharides by reversed-phase high-performance liquid chromatography with refractive index detection using a new type of RP-C₁₈ column (150 × 4.6 mm, 4 µm) with polar end-capping. The validated methodology was also used to characterize grape juice and fine wine products from Northeastern Brazil; and presented suitable linearity, precision, recovery, limits of detection and quantification. The method presented good specificity, revealing that sugars, organic acids, and ethanol (the main interferences in refraction detection) did not influence the quantification of the studied oligosaccharides. The main oligosaccharide found was 1-kestose (approximately 50% of the samples), followed by raffinose (20% of the samples). The results obtained in this are an indication that grape juices and wines have the potential to be functional beverages in relation to the presence of prebiotics.

Volatile Profiles of Sparkling Wines Produced by the Traditional Method from a Semi-Arid Region

São Francisco Valley (SFV) is located in Northeastern Brazil, in a tropical semi-arid region where one vine can produce two harvests per year, due to high temperatures, solar radiation rates, and irrigation throughout the year. This is the main characteristic differing this from other winegrowing region in the world. The objective of this study was to characterize volatile profiles of sparkling wines produced by the traditional method, using Chenin Blanc and Syrah grapes, the two main varieties used for white and red wines, respectively, grown in the region. The sparkling wines remained on lees for six months maturing. The sparkling wines were characterized by the parameters density, pH, total titratable and volatile acidities, residual sugars, dry extract, alcohol content, total phenolic compounds, in vitro antioxidant activity and volatile fraction. The volatile fraction extraction was performed by the HS-SPME technique and tentative identification of the volatile compounds was carried out with GC-MS using the scan mode. A total of 33 volatile compounds were identified, among them 11 alcohols, 13 esters, five carboxylic acids, and four different chemical classes. The volatile profile of Chenin Blanc sparkling wine was associated mainly to 2,3-butanediol, 3-ethoxypropan-1-ol, diethyl succinate, and ethyl decanoate, while Syrah sparkling wine was characterized by benzaldehyde, butyric acid, and some acetates. This study reported for the first time volatile profiles of traditional sparkling wines from SFV, as new products, contributing to better understand the quality potential of these beverages for a tropical semi-arid region.

Evolution of Phenolic Compound Profiles and Antioxidant Activity of Syrah Red and Sparkling Moscatel Wines Stored in Bottles of Different Colors

The objective of this study was to evaluate the effects of storage time and bottle color on the phenolic compound profiles of Syrah red and sparkling Moscatel wines stored for 12 months in green, amber, and clear bottles. The profile of the phenolic compounds and their antioxidant activity in vitro were determined. Commercial wines were bottled in an automatic filling machine and closed with natural cork. After the bottling process, the wines were stored vertically on shelves which received natural light indirectly (±8 h/day), at temperatures which varied from 24 to 30 °C and relative humidity 40–65%. The wines were analyzed every three months over one year. Several phenolic compound families were quantified through reversed-phase high performance liquid chromatography (RP-HPLC) coupled to diode-array detection (DAD) and fluorescence detection (FD). The different bottle colors studied had not influenced the evolution of the sparkling Moscatel and Syrah red wines. The main variations obtained were related to storage time. The main changes were observed in the Syrah wine, where storage time was associated with an increase in hue (h*), decrease in catechin and epicatechin, and most notably, a decrease in the anthocyanin malvidin 3-glucoside. The sparkling Moscatel wine did not show important changes in most phenolic compounds; however, the catechin increased significantly during storage and this increase was similar in bottles of all colors. In general, the wines were stable in relation to the antioxidant activity in vitro.

Evaluation of phenolic compounds, antioxidant and antiproliferative activities of 31 grape cultivars with different genotypes

This study evaluated the total phenolic content, phenolic composition, antioxidant and in vitro antiproliferative properties of seeds and skins of 31 different grape cultivars. These properties of seeds and skins varied greatly among grape cultivars. European grapes had the highest values of phenolic compounds, antioxidant properties in seeds followed by Muscadine > American grapes > Oriental grapes. European grape seed extracts also were the strongest in inhibiting the growth of HepG2 cell, followed by American grapes > Muscadine > Oriental grapes. While these values of the Euro-Asian or Euro-American hybrids fell between the parents. However, the differences of these values in skin extracts among different grape cultivars were not significant. The antiproliferative activities were significantly correlated to the three antioxidant assays and the main phenolic compounds. PRACTICAL APPLICATIONS: This study presents phenolic compounds, antioxidant, and in vitro antiproliferative properties of seeds and skins of 31 different grape cultivars. The information is highly relevant to the ever-increasing need for natural sources of antioxidants or nutraceuticals among consumers. The study also provides information for grape geneticists to breed cultivars with higher nutritional value, and for food scientists to exploit the natural polyphenol antioxidants in various grape pomace.