Non-alcoholic wines: evaluation of chemical profile and biological properties

Introduction The global market of non-alcoholic wine products has significantly grown, most likely driven by the increasing demand for low-alcohol alternatives for health and dietary purposes. A survey conducted in 2023 among 5.500 consumers in 15 Member States by the European General Directorate for Agriculture and Rural Development, showed an increasing interest towards non-alcoholic beverages, including wine. The possibility to drink more freely with respect to alcoholic drinks (e.g., drinking and driving, during pregnancy, etc.) and health benefits (e.g., less calories, lower/no alcohol content maintaining the functional molecules) are among the main reasons encouraging the consumption of dealcoholized wines. There are several processing techniques that can be applied in different stages of winemaking to obtain alcohol-free or with lower alcohol content. However, only post-fermentative techniques are allowed according to EU regulation 2117/2021. Despite the increasing attraction and market growth, few studies in the literature have deeply examined the impact of dealcoholisation process on chemical composition, especially polyphenols, and biological activities of wines. Therefore, this study aims to explore different dealcoholized wines on the market in terms of chemical profile and biological effects, including oxidative stress and gastric inflammation. Materials and Methods Different alcohol-free wines available on the Italian market were included in the study: one white wine (from Muscat de Alejandría grapes); one red wine (from Greanche and Syrah grapes); one rosé wine (from Syrah and Cabernet Sauvignon grapes); one white sparkling wine (from Muscat de Alejandría grapes). Dealcoholized wines were compared with their alcoholic counterparts. Chemical analysis included: total polyphenols content (by Folin-Ciocalteu’s assay), total flavonoids content (by aluminum chloride colorimetric method), total anthocyanins content (by pH differential method applied to red and rosé wines), total carotenoids content (applied to white wine) and the aromatic profile (by GC-MS). The biological tests included the in vitro evaluation of antioxidant properties (using DPPH and ABTS assays) and anti-inflammatory activities. The latter was investigated in gastric cells, measuring the release of pro-inflammatory cytokines (IL-8 and IL-6) using ELISA assay. NF-κB was explored as the main target of the inflammatory pathway. Finally, a panel test has been conducted among non- trained students (>23 years old) and academics (>45 years old) to evaluate some organoleptic characteristics (colour, taste and aroma) and the appreciation of non-alcoholic wines. Results Total phenol content (TPC) of white and rosé dealcoholized products, compared with their alcoholic counterparts, was similar and ranged between 180 and 200 mg/L gallic acid equivalents (GAE). A significant difference was found among red wines: from 824 mg/L GAE (in alcohol-free wine) to 1490 mg/L GAE (alcoholic wine). Antioxidant activity of wines showed a similar trend. Volatile acids and polyalcohols were the most abundant compounds responsible for the aromatic profile. Promising results were also obtained in inhibiting inflammation in gastric cells.