Mead production: effect of nitrogen supplementation on growth, fermentation profile and aroma formation by yeasts in mead fermentation

Abstract

Mead is an alcoholic beverage, produced since ancient times, resulting from an alcoholic fermentation of diluted honey by yeasts. When it is produced in a traditional manner, mead producers can encounter several problems related to a lack of essential nutrients, such as available nitrogen. Thus, the aim of this study was to evaluate the effect of nitrogen addition to honey-must on the fermentation performance of two Saccharomyces cerevisiae wine yeasts, QA23 and ICV D47, as well as on the mead composition and production of volatile aroma compounds. A portion of honey-must was supplemented with diammonium phosphate (DAP) to achieve the nitrogen concentration required by yeast to complete alcoholic fermentation. The supplementation with DAP reduced the fermentation length to around 7 days, but not all sugars were fully consumed, suggesting that other factors could be interfering with yeast growth. For both yeasts the specific growth rate and final biomass were higher in musts supplemented with DAP. Mead final composition was similar under the two experimental conditions. Analysis of the volatile profile revealed that the concentrations of the volatile fatty acids and volatile phenols were higher in meads supplemented with DAP. The concentrations of ethyl hexanoate, ethyl octanoate and isoamyl acetate were above their perception threshold and were higher in meads supplemented with DAP, which could contribute to the enhancement of the fruity character. This study could be useful for the optimization of mead production and quality improvement.

Authenticity Assessment of the “Onisiówka” Nalewka Liqueurs Using Two-Dimensional Gas Chromatography and Sensory Evaluation

“…According to Śliwińska et al (2016a), this beverage may be labeled nalewka, because it is prepared exclusively in homemade conditions. In addition, the main ingredient of this beverage is honey; therefore, the BOnisiówka^nalewka liqueur should not be confused with mead, which is produced by yeast alcoholic fermentation of diluted honey (Pereira et al 2014(Pereira et al , 2015Dobrowolska-Iwanek 2015).…”

Mead and Other Fermented Beverages

“…Even under these improved conditions, the available sugars were not completely consumed by yeasts and a certain amount of residual assimilable nitrogen remained in all of the meads, even in controls to which no nitrogen was added, suggesting that other factors could account for the reduced yeast activity in honey must fermentation. In addition to reducing the fermentation length and increasing specific growth rate of yeasts, the addition of DAP to honey must can contribute to the enhancement of the fruity character of mead [86].…”

“…The aroma of mead has contributions from honey, inoculated yeast, and technological processes [2,81,83,85,86].…”

“…The production of volatile compounds is affected by several factors, including the yeast strain [81,99], cell condition (free or immobilized) [85], and inoculum size [83], as well as by the fermentation conditions [89]. In addition, the type of honey [89,123,124], and the honey must composition/formulation [4,82,86,88] can also modulate the formation of volatile compounds. The volatile compounds produced by yeasts are alcohols, organic acids, esters, volatile fatty acids, carbonyl compounds, and volatile phenols, among others.…”

“…Alcohols are secondary yeast metabolites and, from a quantitative point of view, are the most important group of volatile compounds produced by yeast during alcoholic fermentation of sugars [125,126], inclusive in mead production [82,83,85,86,88]. Alcohols include 2-methyl-1-propanol (isobutanol), 2-methyl-1-butanol, 3-methyl-1-butanol (isoamyl alcohol), and 2-phenylethanol (with pleasant rose-like aroma), among others [125,126].…”