The influence of hydrocolloids on mead wort fermentation

The Impact of Furfural on the Quality of Meads

Furfural is a naturally occurring compound in bee honey, classified as a fermentation inhibitor. The aim of this study was to ascertain the concentration of furfural in mead worts, prepared at room temperature (unsaturated) and heated to boiling for 10 to 70 min (saturated), with an extract of 25 to 45°Brix. Moreover, the impact of the furfural on the fermentation course of mead wort was assessed. For this purpose, fermentation tests were conducted using mead wort (30°Brix) to which furfural was added at concentrations ranging from 1 to 100 mg/L. HS-SPME-GC-TOF-MS analysis revealed that the furfural concentration in mead worts varied between 2.3 and 5.3 mg/L. In saturated worts, the concentration increased by 2.8 to 4.5 times. Acidification of mead wort prior to boiling led to further increase in furfural concentration. The greatest changes occurred in the least concentrated worts, having the lowest buffer capacity. The addition of furfural to the mead wort did not inhibit fermentation, and an increase in attenuation was observed in the samples containing 2 mg/L of furfural compared to the control. Throughout the fermentation most of the furfural was reduced to furfuryl alcohol.

Growing conditions of Saccharomyces boulardii for the development of potentially probiotic mead: Fermentation kinetics, viable cell counts and bioactive compounds

Mead is an alcoholic beverage produced by the fermentation of a diluted honey solution by the action of yeast. Recently, research has shown the potential of S. boulardii for brewing beer and in the development of probiotic alcoholic beverages and, to date, no research has examined for mead production. The aim of this study was to evaluate the growth conditions of S. boulardii for the development of potentially probiotic mead. The findings show that initial wort soluble solids conditions of 30°Brix and initial concentration of 0.030 g/L of S. boulardii obtain potentially probiotic mead with viable yeast cells of 6.53 Log10 CFU/mL, alcohol content of 5.05%, and has the presence of total phenolics (17.72 mg GAE/100 mL) and natural antioxidants (62.79 and 1.37 µmol TE/100 mL for ABTS and FRAP methods, respectively). In conclusion, S. boulardii has a potential for the development of probiotic mead.

Changes in the Antioxidative Activity and the Content of Phenolics and Iridoids during Fermentation and Aging of Natural Fruit Meads

The aim of the study was to investigate changes in the content of biologically active compounds during the fermentation and aging of natural meads with the addition of three Cornelian cherry juices from three cultivars: 'Koralovyi', 'Podolski' and 'Yantarnyi', in the amount of 10% v/v. After the fermentation process the content of gallic and ellagic acids significantly increased, in relation to wort. Whereas the greatest losses were observed among unstable anthocyanins. The three-month aging process also reduced the content of the analyzed compounds except for ellagic acid, the content of which increased by up to 90%. The content of biologically active compounds, including iridoids and antioxidant phenolics, are constantly changing in the process of fermentation and aging of fruit meads. The studies proved that the addition of Cornelian cherry juice allows significantly enriched classic meads with new biologically active compounds, such as: exceptional iridoids (loganic acid, cornuside, loganine, sweroside), flavonols, phenolic acids and anthocyanins.

Rapid analysis of phenyl isothiocyanate derivatives of amino acids present in Czech meads

Amino acids (AAs) are minor compounds occurring in meads contributing to their final organoleptic properties. Determination of AAs profile and content can help to assess the mead authenticity, adulteration and thus its quality. This work deals with the optimization of rapid analysis of 21 AAs present in mead using reversed-phase high performance liquid chromatography with spectrophotometric detection after simple derivatization procedure with phenyl isothiocyanate agent without any sample pre-treatment. Optimized derivatization and separation conditions have been successfully applied to the quantification of AAs present in five Czech meads using the multiple point standard addition method. The total amino acid content was in the range of 134-828 mg/L. The content of proline was confirmed by Harmonised spectrophotometric method. Both chromatographic and spectrophotometric methods provided overlapping results in the range of 30-266 mg/L.

Fruit and herbal meads - Chemical composition and antioxidant properties

The aim of the study was to determine the effect of fruit additives such as syrup from chokeberry or grape seeds, and herbal in the form of a dandelion syrup on the course of the fermentation process of "trójniak" type meads, on their physicochemical and antioxidant properties. The addition of grape seeds allowed for the highest final alcoholic content, which was measured by HPLC, ie 120.73 g/L, and for obtaining a beverage with the highest overall polyphenol content measured by the Folin-Ciocialteu reagent method: 23.18 mg GAE/100 mL, while in the control sample (without additives) it was successively: 91.38 g/L and 12 mg GAE/100 mL. Our research shows that different various of fruit and herbal have a significant impact on the course of the mead fermentation process and on their composition and on the content of biologically active compounds.

Characteristics of Biologically Active Compounds in Cornelian Cherry Meads

In this study, we investigated the effect of Cornelian cherry cultivars differing in fruit color ("Yantaryi"-yellow fruits, "Koralovyi"-coral fruits, "Podolski"-red fruits) on physicochemical characteristics, antioxidative properties, and contents of iridoids and polyphenols in meads with the addition of juices made of their fruits. "Trójniak" type meads (1:2 honey to water volume) were manufactured from multifloral honey, to which Cornelian cherry fruit juice was added before fermentation. Concentrations of individual iridoids and polyphenols were determined using HPLC analysis with a thermostat refractometric detector, model RID-10A. The total polyphenol content was determined based on testing with Folin⁻Ciocalteu (F-C) reagent, whereas the antioxidative properties were determined using DPPH^• (2,2-Diphenyl-2-picryl-hydrazyl), ABTS^•⁺ (2,2'-Azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid), and FRAP (ferric reducing antioxidant power) assays. Cultivar of Cornelian cherry fruits influenced both the antioxidative properties and the concentrations of polyphenols and iridoids. The highest concentration of total polyphenols (F-C), accounting for 898.7 mg gallic acid (GAE)/L, was determined in the mead with juice made of red fruits; this mead was also characterized by the strongest antioxidative capabilities measured with ABTS^•⁺ and FRAP assays. Among the iridoids determined in the Cornelian cherry meads, loganic acid was found to prevail and its highest concentration, reaching 77.8 mg loganic acid (LA)/L mead, was determined in the mead with the coral-fruit juice. Study results indicate that Cornelian cherry meads have a high content of biologically active iridoids and phenolic acids which display valuable antioxidative properties.