Fruit and herbal meads - Chemical composition and antioxidant properties

Water kefir in co-fermentation with Saccharomyces boulardii for the development of a new probiotic mead

Mead is an alcoholic beverage obtained by fermenting a dilute solution of honey with yeasts. The aim of this study was to develop and evaluate a probiotic mead from the co-fermentation of water kefir and Sacharomyces boulardii. According to the results, the combination of 10 g/L of water kefir grains and 0.75 g/L of S. boulardii, with a fermentation time of 9 days, produced a probiotic mead with a viable cell count of more than 8 Log10 CFU/mL of S. boulardii and also for lactic acid bacteria, respectively. S. boulardii and lactic acid bacteria showed counts of over 6 Log10 CFU/mL after gastrointestinal simulation in vitro, with a survival rate of over 70%. Probiotic mead has good luminosity (L*), a tendency to yellow color and the presence of total phenolic compounds and antioxidants. In conclusion, the co-fermentation of water kefir and S. boulardii has potential for the development of probiotic mead.

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.

Kinetic Evaluation of the Production of Mead from a Non-Saccharomyces Strain

There is a growing market for craft beverages with unique flavors. This study aimed to obtain a palate-pleasing mead derived from Pichia kudriavzevii 4A as a monoculture. Different culture media were evaluated to compare the fermentation kinetics and final products. The crucial factors in the medium were ~200 mg L-1 of yeast assimilable nitrogen and a pH of 3.5-5.0. A panel of judges favored the mead derived from Pichia kudriavzevii 4A (fermented in a medium with honey initially at 23 °Bx) over a commercial sample produced from Saccharomyces cerevisiae, considering its appearance, fruity and floral flavors (provided by esters, aldehydes, and higher alcohols), and balance between sweetness (given by the 82.91 g L-1 of residual sugars) and alcohol. The present mead had an 8.57% v/v ethanol concentration, was elaborated in 28 days, and reached a maximum biomass growth (2.40 g L-1) on the same fermentation day (6) that the minimum level of pH was reached. The biomass growth yield peaked at 24 and 48 h (~0.049 g g-1), while the ethanol yield peaked at 24 h (1.525 ± 0.332 g g-1), in both cases declining thereafter. The Gompertz model adequately describes the kinetics of sugar consumption and the generation of yeast biomass and ethanol. Pathogenic microorganisms, methanol, lead, and arsenic were absent in the mead. Thus, Pichia kudriavzevii 4A produced a safe and quality mead with probable consumer acceptance.

Evaluation of sensory acceptance, purchase intention and color parameters of potentially probiotic mead with Saccharomyces boulardii

Mead is a fermented alcoholic beverage produced by yeast action on a diluted solution of honey. In this study, for the first time, sensory acceptance, purchase intention and color parameters of potentially probiotic mead with Saccharomyces boulardii were evaluated. The mead with S. boulardii presented yeast counts higher than 106 CFU/mL, being considered potentially probiotic, and tended to be yellow in color. About 160 tasters participated in the sensory evaluation, and 69.38% knew mead, but only 35.62% had tried the beverage. In terms of acceptance, the mead were within the acceptable range (above 5), and F2 (with initial soluble solids of 30° Brix and S. boulardii concentration of 0.030 g/L) was the most accepted, with an overall average of 7.63 ± 1.42 on the nine-point hedonic scale. In addition, F2 presented the highest purchase intention. In conclusion, the mead showed a tendency towards the color yellow and good sensory acceptance.

The beneficial effect of peppermint (Mentha X Piperita L.) and lemongrass (Melissa officinalis L.) dosage on total antioxidant and polyphenol content during alcoholic fermentation

Our research aimed to create an herbal fermented alcoholic beverage with high antioxidant and polyphenol content. In this study, continuous sampling was performed throughout the fermentation period, and the changes in total antioxidant (TA) and total polyphenol (TP) contents were determined. After processing the raw material, the prepared herbs were added in 0.5 and 1.0 v/v% concentrations to the samples. The TP content of the control sample was between 1.17 and 1.57 mg/g, and the TA content was 2.12 and 2.54 mg/g during the fermentation process. The lemongrass dosage increased 77.86 % the antioxidant and 70.98 % the polyphenol content by the end of the fermentation process. In the best case, the peppermint dosage increased 72.80 % of the antioxidant content and 72.05 % of the polyphenol content. Overall, fermentation combined with herbs dosage could increase the bioavailability of products made from its polyphenol and antioxidant contents and can be used to develop novel functional foods.

Effect of Wort Boiling on Volatiles Formation and Sensory Properties of Mead

Mead is an alcoholic beverage based on bee honey, which can be prepared in different variations such as modified honey-water compositions, the addition of spices, and the use of different yeast strains. Moreover, the technological process of mead production such as the step of wort preparation (with or without boiling of wort before fermentation) can be modified. All these factors might have a significant impact on the formation of aroma-active compounds, and therefore, sensory acceptance by consumers. High vacuum distillation, using the so-called solvent assisted flavor evaporation (SAFE) technique, or headspace-solid phase microextraction (HS-SPME) were applied for the isolation of the odorants. A sensory profile was used to monitor the changes in the aroma of the mead samples. Twenty-eight aroma-active compounds were detected during aroma extract dilution analysis (AEDA) based on gas chromatography-olfactometry (GC-O) and were finally identified by gas chromatography-mass spectrometry (GC-MS) using authentic reference compounds, including methyl propanoate, methyl 3-(methylthio)propanoate, and methional, all of them were identified for the first time in mead. Compounds with high flavor dilution (FD) factors were quantitated via stable isotope dilution analysis (SIDA) and revealed ethyl acetate (16.4 mg/L) to be the most abundant volatile compound, increasing to 57 mg/L after wort boiling, followed by ethyl hexanoate (both 1.2 mg/L). Furthermore, key aroma compounds were esters such as ethyl hexanoate, ethyl octanoate, and ethyl 3-methylbutanoate. The sensory panel evaluated ethanolic, honey-like, clove-like, sweet, and fruity notes as the main aroma descriptors of mead. The significant change in sensory evaluation was noted in the sweet odor of the heat-treated 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.

Influence of blackberry juice addition on mead fermentation and quality

Introduction. Mead, one of the oldest alcoholic beverages that man consumed is obtained by fermentation of honey solution, and contains from 8 to 18% vol. ethanol. Honey can be considered as an excellent source of carbohydrates for the fermentation process, but low concentrations of other substances in the honey can slow down the process. Blackberry (Rubus fruticosus L.) contains dietary fibers, vitamin C (ascorbic acid), vitamin A, vitamin E, potassium and calcium, along with the phenolic metabolites that are a source of possible health benefits. Study objects and methods. In this study was investigated the influence of blackberry juice addition on mead fermentation process, chemical composition and antioxidative activity. Dynamics of the fermentation process were controlled based on weighing the flasks in time on a scale every 24 h throughout the alcoholic fermentation. At the end of fermentations, oenological parameters of mead: dry matter content, pH, volatile acidity and ethanol content and reducing sugars. For the determination of antioxidative capacity the content of total phenolics, total flavonoids and total flavonols were measured and two tests were performed: DPPH and ABTS. Results and discussion. Addition of blackberry juice had a positive effect on fermentation dynamics (almost 25% higher rate of fermentation than in control samples), and improved all physicochemical characteristics and composition of resultant meads. Also, meads with the addition of blackberry juice had a significantly higher concentration of total phenolics, total flavonoids and total flavonols and significantly stronger antioxidative properties compared to the control meads without juice addition. The highest total phenolics, total flavonoids and total flavonols content was determined in the mead with the maximum addition of blackberry juice (B20W): it reached 490.88, 50.34 and 62.57 μgQE.mL–1, respectively, and was 6-fold higher for total phenolics and total flavonoids content, and 10-fold higher for total flavonols content than in the mead without juice addition (CW). The strongest antioxidative activity was determined in the B10W mead; it accounted for 6.98 μgTE.mL–1 (DPPH assay) and 0.65 μgTE.mL–1 (ABTS assay), what was 1.5-fold and 3-fold higher, respectively, than in the mead without juice addition (CW). Conclusion. The conducted study demonstrated that the use of blackberry juice influenced the course of fermentation of meads as well as their physicochemical and antioxidative properties (positive effect on fermentation dynamics – almost 25% higher rate of fermentation than in control samples, and improvement of all physicochemical characteristics and composition of resultant meads).

Antioxidant Effects of Hemp (Cannabis sativa L.) Inflorescence Extract in Stripped Linseed Oil

The ability of hemp (Cannabis sativa L.) inflorescence extract to counteract lipid oxidation was studied in stripped linseed oil. The ethanolic extract was characterized in terms of terpenes (6.00 mg/mL), cannabidiol (4.99% w/w), phenolic compounds (1.80 mg gallic acid equivalents (GAE)/mL), antiradical, and metal ion-chelating activities (50% effective concentration (EC50) of 2.47 mg/mL and 0.39 mg/mL, respectively). The stripped linseed oil, used as control (CO), was mixed with hemp extract (HO) or α-tocopherol (EO) at a ratio of 0.6% (w/w) and stored for 7 days in darkness at 40 °C. Hemp extract reduced the oxidation and lipolysis processes. At the end of the storage, HO showed a significantly higher level of α-linolenic acid (ALA; 26.64 g/100 g), lower peroxide value (PV) (21.19 meq O2/kg oil), and lower hexanal content (7.67 mmol/kg oil) than those found in the control. In contrast, EO showed a marked lipolysis (the free fatty acids increased by 42.57%) and a noticeable oxidation, since the ALA content decreased by 2.10% and a PV of 50 meq O2/kg oil was observed. This study demonstrates that hemp inflorescences can be used as a source of natural antioxidants in vegetable oils and lipid products to retard their oxidation, especially those characterized by a high degree of unsaturation.

Volatile Composition and Sensory Properties of Mead

Mead is a traditional beverage that results from the alcoholic fermentation of diluted honey performed by yeasts. Although the process of mead production has been optimized in recent years, studies focused on its sensory properties are still scarce. Therefore, the aim of this work was to analyse the sensory attributes of mead produced with free or immobilized cells of the Saccharomyces cerevisiae strains QA23 and ICV D47, and to establish potential correlations with its volatile composition. In the volatile composition of mead, the effect of yeast condition was more important than the strain. In respect to sensory analysis, the most pleasant aroma descriptors were correlated with mead obtained with free yeast cells, independently of the strain. Both sensory analysis and volatile composition indicates that the most pleasant mead was produced by free yeast cells. Although this study has provided a significant contribution, further research on the sensory quality of mead is still needed.

Thyroid Peroxidase Activity is Inhibited by Phenolic Compounds-Impact of Interaction

The aim of this study was to estimate the mode of thyroid peroxidase (TPO) inhibition by polyphenols: Chlorogenic acid, rosmarinic acid, quercetin, and rutin. All the tested polyphenols inhibited TPO; the IC50 values ranged from 0.004 mM to 1.44 mM (for rosmarinic acid and rutin, respectively). All these pure phytochemical substances exhibited different modes of TPO inhibition. Rutin and rosmarinic acid showed competitive, quercetin-uncompetitive and chlorogenic acid-noncompetitive inhibition effect on TPO. Homology modeling was used to gain insight into the 3D structure of TPO and molecular docking was applied to study the interactions of the inhibitors with their target at the molecular level. Moreover, the type and strength of mutual interactions between the inhibitors (expressed as the combination index, CI) were analyzed. Slight synergism, antagonism, and moderate antagonism were found in the case of the combined addition of the pure polyphenols. Rutin and quercetin as well as rutin and rosmarinic acid acted additively (CI = 0.096 and 1.06, respectively), while rutin and chlorogenic acid demonstrated slight synergism (CI = 0.88) and rosmarinic acid with quercetin and rosmarinic acid with chlorogenic acid showed moderate antagonism (CI = 1.45 and 1.25, respectively). The mixture of chlorogenic acid and quercetin demonstrated antagonism (CI = 1.79). All the polyphenols showed in vitro antiradical ability against 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), ABTS. The highest ability (expressed as IC50) was exhibited by rosmarinic acid (0.12 mM) and the lowest value was ascribed to quercetin (0.45 mM).