Fermentation characteristics of mead and wine generated by yeasts isolated from beehives of two Austrian regions

Abstract

Mead is a traditional alcoholic beverage that is produced by fermentation of diluted honey.The mead quality is primarily influenced by the honey variety, although the yeast microflora as the main catalyst of alcoholic fermentation also plays a significant role in the organoleptic and chemical quality of the final product. The impact of the indigenous honey associatedyeasts on the mead properties has scarcely been investigated. To fill this gap the main objective of this work was to assess the metabolic properties of the yeasts isolated from honey and pollen from beehives of northeast Austria.The biodiversity was low and only two yeast species were identified, Zygosaccharomyces rouxii and Candida apicola. The fermentation potentials of these yeasts were estimated in two media, grape juice (since yeasts isolated from honey may be useful for sweet wine production) and diluted honey of similar sugar concentration, and compared with those of the reference strains Saccharomyces cerevisiae; S. uvarum and S. eubayanus. Depending on the fermentation substrate, yeasts differed with respect to their metabolic power, fermentation rate, sugar utilization and production of glycerol and organic acids. During mead fermentation Saccharomyces species showed the highest metabolic turnover, while the fermentation rate did not differ significantly. Addition of assimilable nitrogen to the diluted honey enhanced fermentation rate of S. cerevisiae, but not of the other species.Fermentation of grape juice occurred much faster than that of diluted honey and differences between yeasts were more pronounced. The S. cerevisiae commercial wine strain, adapted to high alcohol concentrations, and S. eubayanus outperformed the others, S. uvarum was comparable with Z. rouxii, while C. apicola had the lowest fermentation rate. Fructophily of Z. rouxii and to a lesser degree of C. apicola was observed in both media. An increased production of glycerol was achieved by S. eubayanus in both media and by C. apicola during the fermentation of honey must. A commercial S. cerevisiae strain, S. eubayanus and Z.rouxii were able to metabolize malic acid in wine. In mead, the S. eubayanus and S. uvarum yeasts showed the tendency of increasing the level of malic acid. Aroma profile depended profoundly on yeast species. This study demonstrates that the composition and complexity of the fermentation substrate determines the activity and the final metabolic outcomes of the studied yeasts.

Biochemical Properties and Molecular Characterization of Fermented Alcoholic Honey (Muratina) Microbes from Mbeere-Kenya

“…The optimization results can be seen in the high alcohol content of almost 20%, which is comparable to commercial wines. This process is similar to other traditionally fermented wines studied before [1,3,[24][25][26].…”

“…Strains of Saccharomyces cerevisiae and Lactobacillus plantarum have been reported before as responsible for spontaneous fermentation of wines [4,24,25,30]. The lack of diversity has been reported before by Gangl, et al [3], this could be due to the fact that not many microorganisms are adapted to the high alcohol content in wines.…”

“…The existence of many tribes with diverse food preferences and cultural practices has contributed to the existence of these traditional foods technologies passed from generation to another. Fermentation of honey into wine is one such technology that has remained relevant over years in many communities [2][3][4].…”

Impact of fining agents on the volatile composition of sparkling mead

“…Mead is a traditional alcoholic beverage (alcoholic strength, by volume, between 8 and 18%) produced by the fermentation by yeasts of diluted honey. The production of mead has been the focus of numerous studies . However, few reports consider the volatile profile of mead and even fewer consider the production and characterisation of sparkling mead.…”

“…The production of mead has been the focus of numerous studies . However, few reports consider the volatile profile of mead and even fewer consider the production and characterisation of sparkling mead. Sparkling wines require a second fermentation and subsequent carbonation following four main methods: classical champenoise or ‘in bottle’; discontinuous or charmat ; the transfer process; and the continuous method .…”