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The purpose of this study was to determine the effect of hydrocolloids on the kinetics of ethanol fermentation in high-sugar mead worts. High osmotic pressure, inhibitors and other factors frequently cause sluggish or stuck mead fermentation. In the experiments, natural hydrocolloids – gum arabic, ghatti, karaya, xanthan gum or carob bean gum – were added in an amount of 0.5 g/L to mead worts. During fermentation, the mass of evolved CO 2 was controlled. Anionic hydrocolloids significantly affected the kinetics of mead wort fermentation, significantly accelerating fermentation and causing higher production of ethanol and reduced volatile acidity and acetic acid synthesis by Saccharomyces cerevisiae . Supplementation with gum karaya allowed an increase of ethanol concentration by about 30% compared to control samples. Application of anionic hydrocolloids resulted in significant reduction of amounts of the cations Ca 2+ and Mg 2+ in the solutions, and increased the clarity of young mead.

Sauerkraut is the most widely produced fermented vegetable in Europe, obtained by spontaneous fermentation of cabbage with indigenous microbiota, mainly lactic acid bacteria (LAB). The aim of this study was to characterise the chemical composition of sauerkrauts obtained from eight late cabbage varieties by two-week fermentation. The amount of LAB/yeast, selected organic acids, sugars, biogenic amines, volatiles (chromatographic methods) and sensory qualities were analysed. Significant differences were found in the chemical composition of sauerkraut depending on the variety of cabbage used and the amount of microorganisms present during fermentation. The amount of lactic acid formed depended on the concentration of sugars in the cabbage and the amount of LAB present during fermentation. A positive correlation between the maximal yeast level during fermentation with the amount of acetic acid and biogenic amines was found. The analysed sauerkrauts, depending on the variety, were characterised by a significantly different level of compounds having ‘green’ odours and sulphur compounds, while alcohols, acetoin derivatives and volatile acid concentration were strongly influenced by the amount of microorganisms present during fermentation. The chemical composition strongly determined the taste/aroma of sauerkraut. The selection of an appropriate cabbage variety is crucial for the quality of the sauerkraut obtained.

The aim of this work was to characterize the physical, chemical and antioxidant properties of selected Polish wines, produced from grapevines cultivated in the cool climate of Podkarpacie. Most of the analysed wines were characterized by a small amount of total extract (less than 4%), by ethanol concentration ranging from 9.9 to 11.0% and by titratable acidity from 4.0 to 8.7 g of malic acid/L. The total polyphenol content was closely correlated with antioxidant activity (R2 = 0.96). Red wines were distinguished from white wines by 4–5 times higher antioxidant activity (671–746 mg of Trolox/100 mL) and by increased total amount of polyphenols (127–135 mg of catechin/100 mL). The prevailing volatile compounds of wines were amyl alcohols and isobutanol. Especially high concentrations of the above compounds were present in liqueur wines (>220 and 180 mg/L, respectively). Polish wines contained also high levels of ethyl acetate (11–161 mg/L).