Comparison of different winemaking processes for improvement of phenolic composition, macro- and microelemental content, and taste sensory attributes of Teran (Vitis vinifera L.) red wines

Phenolic budget in red winemaking: Influence of maceration temperature and time

This study investigates the effects of maceration temperature (24 or 29 °C) and duration (12, 18, or 24 days) on phenolic compounds during 'Nebbiolo' wine-like extraction and lab-scale winemaking. In wine-like maceration, anthocyanins quickly peaked and then decreased, with temperature alone showing limited influence on extraction or degradation. In lab-scale fermentations, the rapid anthocyanin extraction at 29 °C was followed by higher degradation, driven by fermentative enzymatic activities and evidenced by increased skin softening at higher temperatures. Longer macerations led to less wine anthocyanins. Tri-substituted anthocyanins were better preserved at 24 °C. Tannin content and structure were minimally affected. Phenolic analyses of grapes, wine, pomace, and lees revealed the extracted, unextracted, resorbed, and degraded phenolic fractions. Reduced anthocyanins in pomace at higher temperatures or extended maceration indicated enhanced extraction and subsequent degradation. The study introduces a "phenolic budget" concept, highlighting the interplay of maceration parameters shaping 'Nebbiolo' wine phenolics.

Evaluating the Impact of Pre-Fermentative and Post-Fermentative Vinification Technologies on Bioactive Compounds and Antioxidant Activity of Teran Red Wine By-Products

This study aimed to evaluate bioactive properties of Teran red wine by-products (grape skins, seeds, and wine lees) from six vinification treatments, including a control (7-day standard maceration). Pre-fermentative cryomaceration (8 °C; 48 h) and hot maceration (50 °C; 48 h), followed by the 13-day (CS15; C15; H15) and 28-day (C30; H30) period, considering fermentation/maceration and extended post-fermentative maceration, were conducted. In CS15, the saignée procedure was applied before fermentation/maceration. After maceration, the separation of by-products was performed, followed by lyophilization and solid-liquid extraction. Then, individual phenols were analyzed using high-performance liquid chromatography (HPLC), and total phenolic content (TPC) and antioxidant activity (FRAP) were analyzed using UV/Vis spectrophotometry. The results showed grape skins and wine lees in all treatments had significantly increased TPC and FRAP values compared to the control. The highest concentration of total phenols (HPLC) in grape skins was found in CS15, at 978.54 mg/100 g DW. In wine lees, the highest concentration of total phenols was detected in the 30-day maceration treatments, at 582.04 mg/100 g DW in C30, and 595.83 mg/100 g DW in H30, despite the pre-fermentative procedure. In grape seeds, the highest concentration of total phenols was found in the control (K7), at 432.42 mg/100 g DW. Pre-fermentative heating together with extended 30-day maceration (H30) strongly reduced the total levels of phenols (HPLC and TPC) in grape seed samples. The findings implied an evident impact of pre- and post-fermentative technologies on phenols and antioxidant activity in wine by-products of cv. Teran (Vitis vinifera L.).

Polyphenolic profile and in vitro biological activity of Serbian orange (skin fermented white) wines

Orange wines are made from white grapes, but with prolonged skin contact during fermentation. Available data on their composition and potential health benefits are limited, so polyphenolic profile (HPLC analysis) and in vitro biological activities (enzyme inhibition, antioxidant, and anti-inflammatory) of 24 Serbian orange wines were analyzed, including the correlation between determined composition and bioactivities. The wines displayed distinct polyphenolic profiles, enabling partial differentiation based on overall polyphenol content, including dominant components (catechin, gallic and caffeic acids), along with occasional occurrences of anthocyanins. However, no discernible distinctions were noted based on grape varieties, vintage, or producer. All twenty-four orange wines showed a reasonable inhibition of digestive enzymes and lipid peroxidation, twenty-one samples reduced ROS generation in the cell-based assay, but only two suppressed both PGE2 and TXA2 production in U937 cells, implicating possible functional food properties. No significant correlation between polyphenolic profile and determined biological activities was noticed.

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.

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

Moderate wine consumption is often associated with healthy lifestyle habits. The role of wine as a healthy drink is mainly due to its bioactive compounds, which differ according to various viticultural and enological factors. The aim of the present study was to observe the differences in bioactive compounds of white and red autochthonous Croatian wines, differing in terms of the grape variety and production technology. Our further aim was to explore the effect of their moderate consumption (200 mL per day) over the course of six weeks on some aspects of health in sixty-six healthy individuals. Participants were divided into eight groups depending on the wines consumed, while one group formed a non-consuming control group. Medical examination and laboratory tests were performed before the start and at the end of the consumption period. Systolic and diastolic blood pressure, total cholesterol, and LDL concentrations decreased. Additionally, an increase in HDL concentrations, and serotonin and dopamine levels, was observed. ALT, ALP, and GGT levels did not significantly increase in consumer groups, although alcohol concentration was relatively high in all the wines. Such results support the beneficial effects of wine-derived bioactive compounds on some health aspects resulting from moderate white and red wine consumption.