Developments in the fermentation process and quality improvement strategies for mead production

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.

Fermented Beverage Benefits: A Comprehensive Review and Comparison of Kombucha and Kefir Microbiome

Beverage fermentation is an ancient ritual that has been practised for millennia. It was slowly disappearing from households and communities due to the advancement of manufacturing technology and the marketing of soft drinks until the recent revival of the beverage fermentation culture due to an increase in the demand for health drinks amid the COVID-19 pandemic. Kombucha and kefir are two well-known fermented beverages that are renowned for their myriad of health benefits. The starter materials for making these beverages contain micro-organisms that act like microscopic factories producing beneficial nutrients that have antimicrobial and anticancer effects. The materials modulate the gut microbiota and promote positive effects on the gastrointestinal tract. Due to wide variations in the substrates and types of micro-organisms involved in the production of both kombucha and kefir, this paper compiles a compendium of the micro-organisms present and highlights their nutritional roles.

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.

Aromatic and sensorial characterization of "Moscato pyments": an innovative beverage

Pyment is a type of mead that is produced from the alcoholic fermentation of a honey solution with the addition of grape juice. Due to the demand for new beverages, pyment can be a profitable alternative for both grape and honey producers. Therefore, this work aimed to characterize the aromatic and physicochemical composition of pyments. The pyments were prepared with addition of 10, 20 and 30% of Moscato juice, and compared with Moscato wine and traditional mead. The results showed an increase in the fermentation rates of Moscato-pyments, indicating that the addition of Moscato juice reverses the low fermentative vigor often reported in mead fermentations. Physicochemical parameters showed an increase in total acidity and a decrease in residual sugar and alcohol, depending on Moscato juice concentration. Moscato-pyments showed an intermediate concentration of volatile compounds between the traditional mead and Moscato wine, with a better balance between fruity, floral and buttery, manifesting characteristic aromas of wines made with Moscato grapes and simultaneously, exposing characteristic aromas of honey. The sensory analysis reveals a significant difference between mead, pyments and Moscato wine. In general, pyments were considered, by the panelists, as the most equilibrated with intermediary aroma intensity, floral, fruity and honey aromas, and good persistence in the mouth.

Dietary alcohol exacerbates the hepatotoxicity induced by pyrrolizidine alkaloids: Hazard from food contamination

Pyrrolizidine alkaloids (PAs) are the most common plant-derived toxins with emerging evidence to contaminate soil, water, nearby plants and derived food products. Outbreaks of human poisoning cases, due to the ingestion of PA-contaminated food, have been reported in various countries including Ethiopia. This study first investigated the contamination of PAs in retail honey in Ethiopia. A striking 77% of honey samples (27/30) were found to contain PAs with the content ranging over 1.5-323.4 μg/kg. Notably, these PAs were also found as contaminants in mead, an alcoholic beverage made from local honey, indicating the transfer of PAs from the primarily contaminated honey into mead. Further toxicological examinations revealed that long-term PA exposure caused vasculature damage, fibrosis, and steatosis in mouse livers, and co-exposure to dietary alcohol exacerbated the PA-induced chronic hepatotoxicity. Furthermore, the study revealed that moderate alcohol intake did not affect the initiation mechanism (hepatic cytochrome P450-mediated bioactivation) of PA-induced hepatotoxicity but significantly disturbed hepatic glutathione homeostasis, thereby increasing oxidative stress in mouse liver and enhancing PA-induced hepatotoxicity. Our findings exemplify the carry-over of PA contamination through the food chain. Precautionary interventions are warranted on the hazardous effects of dietary exposure to PAs, particularly with concomitant alcohol consumption.

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.

Characterization of a new type of mead fermented with Cannabis sativa L. (hemp)

Mead, one of the oldest existing drinks, is a fermented product based on honey, water, and the possible addition of spices and selected yeasts. In this work, various parts (inflorescences, leaves, and steams) of Cannabis sativa L. at different concentrations and Saccharomyces cerevisiae biotype M3/5 were added during mead fermentation. The physicochemical parameters (pH, alcoholic content, sugar content, titratable acidity, and organic acids) of the mead were assessed at the beginning and end of fermentation. Moreover, polyphenols, cannabidiol and volatile organic compounds were identified at the end of fermentation and compared with the control sample prepared without hemp and with only indigenous yeasts. The mead fermented with hemp showed the highest quantity of polyphenols (227 to 256 mg GAE/L) and a level of cannabidiol ranging from 0.26 to 0.49 mg/kg. The volatile organic compounds found were mainly alcohols, esters and terpenes, which were present at higher concentrations in the mead prepared with C. sativa L. than in the control mead and conferred freshness and "hemp aroma" characteristics. PRACTICAL APPLICATION: Inflorescences, leaves, and steams of Cannabis sativa L. were added at different concentrations during mead fermentation. This type of mead showed high quantity of polyphenols (227 to 256 mg GAE/L) and a level of cannabidiol ranging from 0.26 to 0.49 mg/kg which have anxiolytic and neuro-protective properties. Moreover the volatile organic compounds found (mainly alcohols, esters, and terpenes) conferred freshness and "hemp aroma" characteristics.

Impact of Fermentation Processes on the Bioactive Profile and Health-Promoting Properties of Bee Bread, Mead and Honey Vinegar

Recently, an increasing interest is paid to bee products obtained as a result of the fermentation process. Some of them can be consumed directly (bee-collected pollen, honey, bee bread etc.), while others are the result of lactic and/or acid fermentation (honey vinegar and honey wine). Bee bread is the result of pollens’ lactic fermentation, whereas mead is obtained by honeys’ lactic fermentation. Moreover, as a result of honey acetic acid fermentation, honey vinegar is obtained. Sensory characteristics and aroma composition have been scarcely studied, which may depend on the starter culture and fermentation process. Along with the medicinal properties they are a vital resource for future researches as they are of particular importance in the food market. In this review, we discuss the aroma-active compounds, taste, and sensorial characteristics of fermented bee products along with the approaches that can be developed for the flavor improvement based on existing technologies. Furthermore, the beneficial effects on human health are also described, with special attention that should be attributed to finding the use of probiotics in these fermented products as health-promoting effects.

Volatile Profile of Mead Fermenting Blossom Honey and Honeydew Honey with or without Ribes nigrum

Mead is a not very diffused alcoholic beverage and is obtained by fermentation of honey and water. Despite its very long tradition, little information is available on the relation between the ingredient used during fermentation and the aromatic characteristics of the fermented beverage outcome. In order to provide further information, multi-floral blossom honey and a forest honeydew honey with and without the addition of black currant during fermentation were used to prepare four different honey wines to be compared for their volatile organic compound content. Fermentation was monitored, and the total phenolic content (Folin–Ciocalteu), volatile organic compounds (HS-SPME-GC-MS), together with a sensory evaluation on the overall quality (44 nontrained panelists) were measured for all products at the end of fermentation. A higher total phenolic content resulted in honeydew honey meads, as well as the correspondent honey wine prepared with black currant. A total of 46 volatile organic compounds for pre-fermentation samples and 62 for post-fermentation samples were identified belonging to higher alcohols, organic acids, esters, and terpenes. The sensory analysis showed that the difference in meads made from blossom honey and honeydew honey was perceptible by the panelists with a general greater appreciation for the traditional blossom honey mead. These results demonstrated the influences of different components in meads, in particular, the influence of honey quality. However, further studies are needed to establish the relationship between the chemical profile and mead flavor perception.

Selection of low nitrogen demand yeast strains and their impact on the physicochemical and volatile composition of mead

Mead is an ancient alcoholic beverage produced through the fermentation of a diluted solution of honey. Due to the peculiar and varied composition of honey, mead production faces several problems, such as slow or stuck fermentations mainly due to the low nitrogen concentration, lack of uniformity of the final product and the production of unpleasant aromas. In this context, this work aimed to select low nitrogen-demand yeast strains and evaluate their potential for the production of mead. Therefore, among 21 commercial wine yeast strains, 5 were selected based on their fermentative behavior at low assimilable nitrogen concentrations. The selected strains were further evaluated for their contributions in meads produced with limited nitrogen availability, and the results showed significant differences on some physicochemical parameters like biomass production, residual sugars, glycerol concentration, and fermentative rate. Moreover, meads obtained with selected strains differed in the concentration of several volatile compounds. The volatile compounds concentration and the principal component analysis based on odor activity values allowed separating strains into three groups. In general, S. cerevisiae var bayanus strains (QA23, Spark, and AWRI-R2) were the largest producers of aromatic compounds, particularly those with floral and fruity descriptors. The selection of yeast strains with low nitrogen-demand and different volatile compounds production can be explored by mead makers to limit fermentation problems and obtain characteristic products.

Mead Production by Saccharomyces cerevisiae Safbrew T-58 and Saccharomyces bayanus (Premier Blanc and Premier Cuvée): Effect of Cowpea (Vigna unguiculata L. Walp) Extract Concentration

This work evaluated the effect of the cowpea (Vigna unguiculata L. Walp) extract concentration on mead production. Fermentations were carried out in 500-mL Erlenmeyer flasks containing 250 mL of honey wort (30 °Brix), supplemented with 1 g L^-1 of ammonium sulfate and 0.1 g L^-1 of magnesium chloride and the cowpea extract (5 and 30 g L^-1), inoculated with 10⁶ cells mL^-1, and incubated at 30 °C for 240 h. Higher cell growth ((cells mL^-1): 11.1 × 10⁷, 11.3 × 10⁷, and 19.6 × 10⁷; substrate consumption (%): 86.0, 90.0, and 85.0) and ethanol production ((v v^-1 %): 15.0, 15.5, and 14.1) for yeasts Safbrew T-58, Premier Blanc, and Premier Cuvée, respectively, were obtained with 30 g L^-1 of bean extract. S. bayanus Premier Blanc had the best metabolic activity with lowest glycerol production (8.5 g L^-1) and highest ethanol volumetric yields (0.51-1.52 h^-1) after 48 h of fermentation.

Physicochemical and Sensorial Characterization of Honey Spirits

Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences (p < 0.05) were also observed in the volatile composition and chromatic characteristics suggesting different production technologies. A first list of sensory attributes was obtained for this beverage. Therefore, further research must be done in order to characterize this spirit drink, which has gained market value.

Effects of Mead Wort Heat Treatment on the Mead Fermentation Process and Antioxidant Activity

The effects of mead wort heat treatment on the mead fermentation process and antioxidant activity were tested. The experiment was conducted with the use of two different honeys (multiflorous and honeydew) collected from the Lower Silesia region (Poland). Heat treatment was performed with the use of a traditional technique (gently boiling), the more commonly used pasteurization, and without heat treatment (control). During the experiment fermentation dynamics were monitored using high performance liquid chromatography with refractive index detection (HPLC-RID). Total antioxidant capacity (TAC) and total phenolic content (TPC) were estimated for worts and meads using UV/Vis spectrophotometric analysis. The formation of 5-hydroxymethylfurfural (HMF) was monitored by HPLC analyses. Heat treatment had a great impact on the final antioxidant capacity of meads.