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In the current review we summarised the research involving solid state fermentation (SSF) for the production of compounds that could be used in healthcare (terpenoids, polyphenols, fibrinolytic enzymes, mycophenolic acid and others). We described several groups of obtained agents which hold various activity: antimicrobial, anti-inflammatory, immunosuppressive, anticoagulant and others (e.g. anticancer or anti-diabetic). It seems that especially terpenoids and polyphenols could be useful in that field, however, other substances such as enzymes and fatty acids play important role as well. We described main groups of microorganisms that are applied in SSF of those compounds, particularly Bacillus genus and fungi, and where possible provided information regarding genes involved in those processes. We also compared various approaches toward optimisation of SSF.

Providing yeast with the right amount of mineral salts before fermentation can contribute to improving the entire technological process, resulting in a better-quality final product. The aim of this study was to assess the impact of apple must supplementation with mineral salts ((NH4)2SO4, MgSO4, (NH4)3PO4)) on enological parameters, antioxidant activity, total polyphenol content, and the profile of volatile cider compounds fermented with various yeast strains. Rubin cultivar must was inoculated with wine, cider, and distillery or wild yeast strains. Various mineral salts and their mixtures were introduced into the must in doses from 0.167 g/L to 0.5 g/L. The control sample consisted of ciders with no added mineral salts. The basic enological parameters, antioxidant properties, total polyphenol content, and their profile, as well as the composition of volatile compounds, were assessed in ciders. Must supplementation with magnesium salts significantly influenced the use of the analyzed element by yeast cells and was dependent on the yeast strain. In supplemented samples, a decrease in alcohol concentration and total acidity, as well as an increase in the content of extract and total polyphenols, was observed compared to the controls. The addition of ammonium salts caused a decrease in the amount of higher alcohols and magnesium salts, as well as a decrease in the concentration of some esters in ciders.

Qualitative and quantitative profiles of volatiles in alcoholic beverages depend mainly on the quality of raw materials, yeasts used for fermentation, and processing technique. Saccharomyces bayanus is a yeast species which is not commonly used for the production of alcoholic beverages, but it is able to produce volatiles that add desirable aroma. Since there is little information regarding the application of that microorganism for the production of apple brandies and how it affects volatile profile of finished products, we decided to address that issue. The aim of the study was to determine the impact of S. bayanus on the profile of volatile compounds and sensory properties of apple spirits obtained from three apple cultivars (Topaz, Rubin, and Elise) in comparison to spirits obtained from fermentation carried out spontaneously or with Saccharomyces cerevisiae. Obtained brandies were analysed using gas chromatography&ndash, flame ionization detector (GC&ndash, FID), solid phase microextraction&ndash, gas chromatography&ndash, mass spectrometry (SPME&ndash, GC&ndash, MS) and sensorially. In our study, brandies produced from musts fermented by S. bayanus demonstrated the highest concentration of ethyl esters and increased concentrations of isoamyl acetate, 2-phenylethyl acetate, ethyl palmitate and hexanol. Moreover, our results support the hypothesis that non-Saccharomyces yeasts which are present during spontaneous fermentation and demonstrate higher &beta, glucosidase activities enhance aroma of alcoholic beverages through releasing aroma compounds from glycosidic forms, e.g., &alpha, phellandrene, (E)-&beta, fanesene, (Z,E)-&alpha, farnesene, &alpha, farnesene, and farnesol. Considering results obtained in sensory analysis, we proved that S. bayanus is suitable for the production of apple brandies, improving their flavour. Brandies obtained from musts fermented by S. bayanus obtained the highest average range for &ldquo, overall note&rdquo, parameter in sensory analysis.

Volatile profile of spirits is the most important factor, because it can contribute to pleasant flavor. The aim of the study was to determine the impact of dessert apple cultivar used for fermentation on the concentration of volatile compounds in apple spirits. SPME-GC-MS (solid-phase microextraction- gas chromatography- mass spectrometry) method enables the detection of 69 substances and GC-FID (gas chromatography - flame ionization detector) 31 compounds. Characteristic volatiles for brandies obtained from Topaz were limonene, myrcene, methyl valerate and 1,1-diethoxy-propane, from Rubin&mdash, &beta, citronellol and isopropyl acetate, Elise&mdash, limonene, myrcene benzyl acetate and isopropyl acetate, Szampion&mdash, citronellol, Idared&mdash, 1,1-diethoxy-propane and Jonagored&mdash, ethyl trans-4-decanoate. Of the ten analyzed apple spirits, those obtained from Topaz, Rubin and Elise cultivars demonstrated the most diverse profile of volatile compounds. Moreover, their oenological parameters that are the most important in the production of alcoholic beverages were the most favorable. On the other hand, the content of sugars was relatively low in Elise must, while it was highest in Topaz must, which later on translated into differences in alcohol content. Brandies obtained from Gloster contained the smallest concentrations of esters and terpenes. Results of the sensory analysis showed that highest rated brandies were obtained from Topaz, Rubin, Elise and Florina.

Keeving consists in the removal of nutrients (which are yeast nutrients) from apple juice, due to their binding with pectin, and is dependent on the concentration of calcium ions. The aim of the study was to assess the effect of different yeast strains on oenological parameters and the profile of volatile cider compounds during the process of keeving. The experiments involved production of cider using different strains of yeast and different doses of CaCl2 in the keeving process. The basic oenological parameters of ciders and volatile compound profiles were evaluated. Keeving has been shown to slow the use of sugars by yeast and, as a result, lower alcohol levels in ciders. The concentration of FAN (free amino nitrogen) after keeving was significantly reduced compared to the control samples. Ciders made by keeving were characterized by higher concentrations of acetates and some terpenoids. In contrast, other volatile esters were present at lower concentrations.

The micro-oxygenation of musts may affect the quality of a finished alcoholic beverage. The aim of this study was to determine the effect of micro-oxygenation at various stages of fermentation on oenological parameters, antioxidant activity, total polyphenol content, and profile of volatile cider compounds fermented with various yeast strains. Rubin cultivar must was inoculated with wine yeast, cider yeast, distillery yeast, and wild yeast strains. Some of the inoculated samples were oxygenated immediately after yeast inoculation, and some on the second and third fermentation days. The control sample was non-oxygenated must fermented in bottles. Higher extract concentration and acidity as well as lower potency were observed in cider treated with micro-oxygenation. Must oxygenation in most cases contributed to the reduction of polyphenol content and to the antioxidant activity of ciders, especially when fermented using wild yeast. The oxygenation of musts before fermentation caused an increase in the content of esters and alcohols in ciders. However, the oxygenation of musts during fermentation reduced the concentration of these volatile components. The oxygenation of musts during fermentation produced a differentiated effect on terpenoid concentration in ciders.