Bioactive Compounds and Antioxidant Activity of Red and White Wines Produced from Autochthonous Croatian Varieties: Effect of Moderate Consumption on Human Health

The Antidiabetic Effect of Grape Skin Extracts of Selected Indigenous Croatian White Grapevine Varieties

Grape skin is an excellent bioactive compound source with numerous beneficial health effects. This study aimed to determine and compare the antidiabetic potential of the grape skin of indigenous Croatian white grapevine varieties. The grape skin extracts (GSEs) were assessed for total polyphenols, antioxidant activity, and inhibition potential against α-amylase and α-glucosidase, enzymes responsible for carbohydrate metabolism. GSE of variety "Svetokriška belina" has the highest total phenols (TP) content (1404.87 mg of gallic acid equivalent), the highest antioxidant capacity against DPPH (544.82 mg ascorbic acid equivalent), and the highest inhibitory activity against α-amylase (99.60%). α-glucosidase was best inhibited by the variety "Kozjak" (93.53%), followed by a significantly lower inhibition by the GSE of "Svetokriška belina" (89.64%). The principal component analysis (PCA) revealed the relationship among the grape varieties by their inhibition potential, where the first PC explained 71.34% of the variation. Indigenous Croatian white grapevine varieties have great potential for developing new natural supplements to prevent and treat diabetes.

Integrated instrumental setup comprising an automatic solution handling module and homemade luminometer with two photodetectors for the determination of antioxidants in wines

This study describes the development of an integrated instrumental setup, comprising a multi-commuted flow analysis module for solution handling and a homemade luminometer assembled with two photodetectors for luminescence detection. This setup controlled by an Arduino Due board was used to develop an analytical procedure for determining antioxidants in red and white wines, using chemiluminescence detection. The analytical procedure is based on the reaction of hypochlorite with antioxidants present in wine, followed of oxidizing reaction with luminol in an alkaline medium (pH > 9). After determining the optimal operational parameters, the following analytical parameters were obtained: linear responses for gallic acid concentrations ranging from 0.75 to 4.0 g L-1 (r2 = 0.999) for red wine and from 75 to 500 mg L-1 (r2 = 0.994) for white wine, a coefficient of variation of 2.71% (n = 9) for a wine sample with an antioxidant concentration of 1.57 g L-1 in gallic acid equivalent, recoveries ranging from 85 to 114%, an analytical throughput of 100 determinations per hour, consumption of 0.35 μg of hypochlorite and 53 mg of luminol per determination, and limits of detection of 0.25 g L-1 and 29 mg L-1 for red and white wine, respectively.

A Comprehensive Review on Polyphenols of White Wine: Impact on Wine Quality and Potential Health Benefits

Polyphenols are associated with various beneficial health effects. These compounds are present in edible plants such as fruits and vegetables, and the human body absorbs them through the consumption of foods and beverages. Wine is recognized as a rich source of these valuable compounds, and it has been well established that polyphenols present in red wine possess numerous biologically active functions related to health promotion. Therefore, most scientific research has been focused on red wine polyphenols, whereas white wine polyphenols have been neglected. This review presents the summarized information about the most abundant polyphenols in white wines, their concentration, their impact on wine quality and their potential health effects, such as neuroprotective and cardioprotective activities, antioxidant potential, antimicrobial activity and their positive effects on lipids. These findings are an effort to help compensate for the relative lack of relevant data in the scientific literature regarding white wine polyphenols.

Pre- and postharvest chitosan coatings extend the physicochemical and bioactive qualities of minimally processed 'Crimson Seedless' grapes during cold storage

BACKGROUND

Food marketers desire residue-free fresh grapes although grapes have a short postharvest life. This study was performed to determine the influences of pre- and/or postharvest chitosan (Ch) coatings on postharvest quality of minimally processed (stem-detached) organic 'Crimson Seedless' berries. Berries were sorted as: (a) control (untreated berries); (b) preharvest Ch (dipping the clusters on the vine into 1% Ch 10 days before harvest at 20% soluble solid content (SSC)); (c) postharvest Ch (dipping the stem-detached berries into 1% Ch); and (d) pre + postharvest Ch. Berries were stored in 12 × 15 cm rigid polypropylene cups for up to 42 days at 1.0 ± 0.5 °C.

RESULTS

Pre- and/or postharvest Ch coating reduced weight loss during storage. Pre- + postharvest Ch was the best treatment for restricting polygalacturonase (PG) activity, extending the visual quality, color features (L*, C and h°), skin rupture force, biochemical (SSC, titratable acidity, maturity index and pH) and bioactive (total phenol content, antioxidant activity) features. Pre- or postharvest Ch was also significantly effective in maintaining many quality features.

CONCLUSION

Pre- and/or postharvest 1% Ch coatings effectively maintained the quality of minimally processed grape berries of organically produced 'Crimson Seedless' grapes by delaying weight loss and PG activity and keeping the postharvest physical, biochemical and bioactive features for 42-day cold storage at 1.0 ± 0.5 °C. The combined use of pre- and postharvest Ch found to be more effective than single treatment. Thus, pre- + postharvest 1% Ch coating could be recommended as an ecofriendly sustainable methodology for extending the postharvest quality of minimally processed fresh grapes. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of the spray-drying process using maltodextrin on bioactive compounds and antioxidant activity of the pulp of the tropical fruit açai (Euterpe oleracea Mart.)

Aҫai fruit is characterized by the properties of its bioactive compounds; however, this fruit is highly perishable and its compounds are sensitive when exposed to non-optimal environmental factors. Therefore, the objective of this study was to encapsulate the fruit pulp by spray drying to improve the nutritional value and extend the shelf life of the products derived from acai fruit. Maltodextrin was used as a wall material and the process was optimized to obtain the desirable values of the response variables. For this, a central compound design (CCD) was developed to determine the influence of temperature (110-170 °C) and the wall material proportion (5-15 %) on dependent variables: the retention of ascorbic acid, moisture percentage, hygroscopicity, solubility, water activity, and yield. Furthermore, the effects of spray drying on bioactive compounds (AA, TPC, TFC, TA, TCC, GA, CT, and QC) and antioxidant activity (ABTS, DPPH, and ORAC) were evaluated. The maximum design temperature (170 °C) and wall material proportion (15 %) significantly influenced the response variables where encapsulation was applied, with high ascorbic acid retention (96.886 %), low moisture (0.303 %), low hygroscopicity (7.279 g/100 g), low level of water activity (0.255), a water solubility index of 23.206 %, and a high yield of 70.285 %. The bioactive compounds analyzed and the antioxidant capacity presented significant retention values for AA (96.86 %), TPC (65.13 %), TFC (82.09 %), TA (62.46 %), TCC (7.28 %), GA (35.02 %), CT (49.03 %), QC (37.57 %), ABTS (81.24 %), DPPH (75.11 %), and ORAC (15.68 %). Therefore, it is concluded that the powder obtained under these conditions has desirable physical properties, and the drying process preserved a notable retention of bioactive compounds and their antioxidant activities.

Applying Different Vinification Techniques in Teran Red Wine Production: Impact on Bioactive Compounds and Sensory Attributes

Six different vinification treatments, including a control treatment (7-day standard maceration) (K7), were performed to study the effects of non-standard techniques on bioactive compounds and sensory attributes of Teran red wine. Pre-fermentative mash cooling (8 °C; 48 h) and heating (50 °C; 48 h) followed by prolonged post-fermentative maceration of 13 days (C15;H15) or 28 days (C30;H30) were applied. In another treatment, after cooling, saignée was performed followed by 13-day prolonged maceration (CS15). Wine phenols and vitamins were analyzed by HPLC-DAD-FLD, minerals by ICP-OES, and sensory analysis was performed using the QDA and 100-point O.I.V./U.I.O.E. methods. Obtained results showed total phenolic concentration was the highest in the H30 treatment. The concentration of anthocyanins, flavan-3-ols and phenolic acids was significantly higher in wines of all vinification techniques compared to the control. Stilbene content was highly affected by pre-fermentative heating. Treatments CS15, H15, C30 and H30 resulted in the highest scores by both the QDA and 100-point sensory methods. The obtained results suggest that advanced non-standard vinification techniques have a significant impact on Teran wine by enhancing its composition of bioactive compounds and improving its sensory profile, which gives it an additional market value. Furthermore, a comprehensive comparison of such techniques applied simultaneously in one study is of substantial importance for additional research in wine production.

The Effect of Hokkaido Red Wines on Vascular Outcomes in Healthy Adult Men: A Pilot Study

Moderate red wine intake has been associated with lower cardiovascular mortality, due in part to the intake of polyphenols and anthocyanins, whose content can vary from varietal and year of harvest. This study assessed the vascular effects in response to a single intake of 2015 and 2018 Zweigelt red wines from Hokkaido, Japan. Healthy men were randomly assigned to consume 240 mL each of a red wine, or a sparkling white grape juice as a control in a randomized three-arm cross-over design with a 7 day washout between arms. The augmentation index (AI; a measure of arterial stiffness) and AI at 75 beats/min (AI75), reactive hyperemia index, systolic and diastolic blood pressure (SBP and DBP, respectively), and platelet reactivity were assessed at baseline and two and four hours after each beverage intake. Changes from the baseline were analyzed using a linear mixed model. Significant treatment effects (p = 0.02) were observed, with AI 13% lower after the intake of the 2015 or 2018 vintages compared to the control. Intake of the 2018 vintage reduced SBP and DBP (-4.1 mmHg and -5.6 mmHg, respectively; p = 0.02) compared to the 2015 wine and the control drink. The amount of hydroxytyrosol in the 2018 wine was almost twice the amount as in the 2015 wine, which may help explain the variable blood pressure results. Future studies exploring the vascular effects of the same red wine from different vintage years and different phenolic profiles are warranted.

Investigation of the Phenolic Component Bioavailability Using the In Vitro Digestion/Caco-2 Cell Model, as well as the Antioxidant Activity in Chinese Red Wine

Red wine is a well-known alcoholic beverage, and is known to have phenolic compounds (PCs), which contribute to its antioxidant activity and have other beneficial advantages for human health. The aim of this study was to evaluate the effect of the simulated gastro-intestinal digestion and the Caco-2 transepithelial transport assay on the PCs, bioavailability, and the antioxidant capacity of red wines. The contents of PCs in red wine were significantly reduced during most of the digestion phases. Phenolic acid had the greatest permeability, while the flavonols had the weakest. The bioavailability of PCs ranged from 2.08 to 24.01%. The result of the partial least squares structural equation model showed that the three phenols were positively correlated with the antioxidant activity of red wine. The contribution of anthocyanins was the largest (0.8667).

Protective Effects of Wine Polyphenols on Oxidative Stress and Hepatotoxicity Induced by Acrylamide in Rats

In recent years, it has been increasingly suggested that the consumption of natural polyphenols, in moderate amounts, is beneficial for health. The aim of this study was to investigate the efficacy of a red wine (the administered dose of 7 mL/kg/day being equivalent to ~16.5 mg/kg/day total polyphenols) compared to a white wine (the administered dose of 7 mL/kg/day being equivalent to ~1.7 mg/kg/day total polyphenols), on the prevention of acrylamide-induced subacute hepatic injury and oxidative stress in Wistar rats. Hepatic damage due to acrylamide intoxication (the administered dose being 250 µg/kg body weight, for 28 days, by intragastric gavage) was assessed by employing biochemical parameters (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) and by histopathological studies. Markers of oxidative damage were measured in terms of plasma malondialdehyde (MDA), hepatic Thiobarbituric Acid Reactive Substances (TBARS) and glutathione (GSH) levels, and liver antioxidant enzyme (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) activities. Regarding hepatic enzyme activities, treatment with red wine significantly decreased the AST values (p < 0.05), while for the ALT values only a normalization tendency was observed. Treatment with red wine and white wine, respectively, significantly prevented the increase in MDA and TBARS levels (p < 0.05), as well as the depletion of GSH (p < 0.05). Red wine treatment normalized the activities of the antioxidant enzymes CAT and SOD in rats intoxicated with acrylamide, while supplementing the diet with white wine did not produce significant differences in the antioxidant enzyme activities. Histopathological findings revealed a moderate protective effect of red wine after four weeks of daily consumption. Our findings provide evidence that red wine, having a higher phenolic content than white wine, has a significant protective effect on oxidative stress and liver injury induced by acrylamide in rats, through its antioxidative activity.