###### Abstract  
Changing consumer preferences and increasing demands require adjustments in brewery operations and beer production methods. Recent trends indicate a marked decline in interest in high-alcohol beers and an increasing demand for low- and no-alcohol alternatives. The aim of this study was to evaluate and compare the volatile compound profiles produced by _Saccharomyces cerevisiae_ var. _chevalieri_, a yeast strain specifically developed for non-alcoholic beer production, with a reference sample fermented with a standard _Saccharomyces cerevisiae_ US-05 strain. Two mashing profiles were compared (with and without saccharification pause). The word obtained was fermented with and without hops. The chemical composition and aroma compounds of the resulting beers were analysed using different chromatographic techniques (HPLC, GC-FID, GC-MS and CG-O). The modification of the mashing profile helped to obtain word with about 50% lower maltose content. A lower FAN (free amino nitrogen) content was also observed, but this did not affect the fermentation process. Beers fermented with the _Saccharomyces cerevisiae_ var. _chevalieri_ strain had an average alcohol content of 0.5-0.8% \(\
icefrac{{v}}{{v}}\). This strain consumed about 25% of the available maltose. The resulting beers were dominated by fruity, floral and herbal aromas. In addition, beers fermented with a non-alcoholic beer strain scored highest in the sensory analysis. low-alcohol beers; volatile compound; aroma-active compound; special yeast strain +
Footnote †: journal: Medical  
Thermal processes expose the beer to a temperature of at least 60 \({}^{\circ}\)C for a prolonged period. This can lead to undesirable changes in the beer, such as darkening, the caramelisation of remaining sugars and deterioration of the aroma composite [10]. Conversely, membrane procedures use semi-transparent membranes by which solutes or solvents selectively migrate (permeate). As the solution passes through the membrane module, the composition of the solution changes [6]. The main aim of biological methods in the production of NoLo beers is to limit the fermentation process, which is carried out with traditional brewing yeast [11]. Already at the mashing stage, the fermentation potential of the wort is reduced by limiting the breakdown of starch into fermentable sugars (maltose, glucose) [12]. Another way to produce low-alcohol beers is to stop fermentation when the alcohol concentration reaches 0.5% \(v/v\). However, beers produced in this way may have a sulphur aftertaste, which is removed during maturation [13]. Yeast strains that ferment the sugars present in the wort poorly or not at all are becoming increasingly popular in the production of NoLo beers [14]. The use of yeast strains with poor maltose fermentation capabilities is currently one of the best methods for producing NoLo beers. The resulting beers are characterised by an appropriate taste without a wort aftertaste [11]. In order to obtain NoLo beers with an appropriate sensory profile, many studies have been carried out on _Saccharomyces strains_ with different phenotypic and genotypic profiles [15]. The _Saccharomyces ludwigii_ strain, which does not have the ability to ferment maltose, is very popular. Beers produced with this strain have a low alcohol content and a fruiter, ester-like flavour [16]. This is also confirmed by research conducted by [PERSON] et al. [17], in which beers produced with this strain were characterised by a fruity-ester aroma with notes of apple. The _Saccharomyces cerevisiae_ var. _chevalieri_ strain is very popular. This yeast is currently the most widely used strain for the production of non-alcoholic beers throughout the brewing industry. Beers produced with this strain are highly accepted by consumers. The taste of the beer is mainly due to the presence of maltose, which is not used by this strain. Maltose is a sugar that adds sweetness to beer. This sugar does not occur in classically fermented beers because it is used up almost entirely by the yeast [18].