Consumption of fermented foods is associated with a wide range of nutraceutical benefits, including antioxidant and antibacterial properties. Because of this, the demand for fermented food products is steadily increasing. Vinegar is a fermented product with many health benefits. The purpose of this work is to characterize and evaluate the antioxidant and antibacterial activities of vinegar produced through a natural two-step fermentation process: an alcoholic fermentation followed by an acetic fermentation. This vinegar is made from two apple varieties, Gala and Golden, and compared with a control composed of industrial vinegar. Prepared vinegars contain varying amounts of nutrients (B, K, Ca, Mg, Na, and Fe), pectins, and β-carotene. Prepared vinegars are richer in these elements compared to industrial vinegar. Vinegar from the Golden variety exhibits higher antiradical activity (IC50 = 20 mg/mL) compared to the Gala variety (IC50 = 40 mg/mL) and industrial vinegar (IC50 = 25 mg/mL).This activity may be influenced by the presence of carotenoids, as demonstrated in this study. However, no clear proportional relationship was observed between carotenoid content and antiradical activity, since the highest carotenoid concentration was found in the vinegar from the Gala variety, which exhibited lower antiradical activity. The antibacterial activity of vinegar samples was evaluated based on their inhibitory effect on bacterial growth. The study focused on measuring inhibition zones, which are widely recognized indicators of antibacterial potential. This approach allowed us to assess the functional antibacterial properties of the vinegars by determining their effectiveness in limiting bacterial proliferation. Antibacterial activity was observed against three bacterial strains: Hafnia alvei, Bacillus subtilis, and Escherichia coli. The vinegar from the Golden variety exhibited greater activity against Hafnia alvei (12 mm vs. 9 mm) and Escherichia coli (9.2 mm vs. 7 mm) compared to the Gala variety, which showed higher activity against Bacillus subtilis, with an inhibition diameter of 10.1 mm. The different properties found in these prepared vinegars can be utilized in different sectors such as the agri-food or nutraceutical sector.

Apple variety, vinegar, phytochemistry, antioxidant activity, antibacterial activity