The aim of this master’s thesis was to determine the influence of six different commercial bentonites and the timing of their addition on the release of metal ions and the aroma of young white wine made from the Laški rizling variety. Different types of bentonites were applied—sodium, calcium-sodium, calcium, and activated calcium bentonites—each added at three different stages: to the must, during alcoholic fermentation, and after fermentation. Metal ion concentrations were determined using ICP-MS, while volatile aromatic compounds were analyzed using HS/SPME-GC/MS. The experiment also included simulated wine aging at elevated temperatures to assess the influence of bentonite type and timing on wine aging and loss of fruitness. The results clearly showed that the timing of bentonite addition has a key influence on the release of metal ions. Addition durig fermentation showed the highest values of iron (1240.7 µg/L) and aluminium (720.9 µg/L). The lowest values of iron, which is known oxidant, were shown by the values of addition of sodium bentonite. Similarly, the lowest copper content (18.3 µg/L) was also observed with sodium bentonite added during fermentation. The aromatic profile was evaluated based on seven groups of volatile compounds and was best preserved with the addition of sodium bentonite during alcoholic fermentation. After simulated aging of the wine, the concentrations increased in ethyl esters of fatty acids, aromatic esters and higher alcohol acetates, which significantly affect the fruitiness of white wine. On the contrary, the addition of calcium bentonite to the must caused the highest loss of aromatic compounds. According to the results, we conclude that the most optimal combination for preserving the aromatic profile and reducing the presence of certain metal ions that act as oxidation catalysts is the addition of sodium bentonite during alcoholic fermentation.
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