Kombucha fermentation was conducted on black tea substrate sweetened with sucrose. Basic kombucha parameters (pH, total acidity and yield of the biomass) were measured in order to establish the time course of the fermentation. Aqueous two-phase systems consisted of polyethylene glycol, ammonium sulfate and crude enzyme, and at different pH values, were applied for kombucha invertase partitioning. The partition coefficient, yield and purification factor of invertase were determined in order to evaluate the success of isolation and purification of the invertase. In system composed from 10% PEG 1500, 20% salt and 30% crude enzyme at pH 5, yield 88.3 ± 4.0% and purification factor 13.6 ± 0.5 in the bottom phase were attained thus enabling integrated recovery and purification of kombucha invertase.

Kombucha is a fermented beverage produced using a symbiotic consortium of acetic acid bacteria and yeasts, often marketed for its health-promoting properties. However, probiotic bacteria in kombucha are typically present at inconsistent levels and may not remain viable during fermentation. In this study, three Lactobacillus strains (Lacticaseibacillus rhamnosus ATCC 53103 (L. rhamnosus), Lactiplantibacillus plantarum subsp. plantarum ATCC 14917 (L. plantarum) and Lentilactobacillus hilgardii (L. hilgardii) isolate) were encapsulated in whey protein using the lyophilization method and added individually at the start of kombucha fermentation. Lactic acid bacteria (LAB)-enriched kombucha samples were evaluated for chemical composition (polyphenols, flavonoids, vitamin C and organic acids) and functional properties (antimicrobial, antiproliferative, antioxidant and anti-inflammatory activities) and compared to a traditionally obtained control kombucha, primarily demonstrating in vitro and experimental assessment. Encapsulation maintained LAB viability above 6-7 log CFU/mL throughout fermentation, producing kombucha with enhanced microbial stability. LAB-enriched samples exhibited increased L-lactic acid and antimicrobial activity. L. rhamnosus and L. hilgardii-enriched samples exhibited increased antiproliferative and anti-inflammatory activities, which may be associated with strain-dependent production of organic acids, polyphenol modulation and LAB-derived bioactive metabolites. Antioxidant activity varied depending on assay, and L. rhamnosus-enriched kombucha showed higher anti-inflammatory activity. These findings demonstrate that whey protein encapsulation can preserve LAB during fermentation, enhance specific bioactive properties and provide a platform for developing functional kombucha beverages with potential applications in the food industry.

The traditional kombucha beverage is produced through the metabolic activity of the microorganisms present in the kombucha culture on sweetened black tea at room temperature. The aim of this study was to investigate the influence of cross-flow microfiltration on the quality of the produced beverage. The produced beverage was microfiltered to assess the effect of cross-flow microfiltration on its quality. The quality characteristics examined included pH, total acidity, total soluble solids, turbidity, organic acids, in vitro antioxidant potential, and vitamin C as an antioxidant compound. The operational parameters of the process were transmembrane pressure (0.2, 0.6, and 1 bar) and feed flow rate (30, 90, and 150 Lh-1). The maximum permeate flux was achieved at the highest feed flow rates and transmembrane pressures. Microfiltration maintained (pH, total acidity, total soluble solids, lactic, formic, and oxalic acid), improved (turbidity and acetic acid), but also declined (malonic acid, vitamin C, and antioxidant potential), the quality of the traditional beverage. After the microfiltration, turbidity was reduced by 7-9 times, and the content of acetic acid amounted to around 1.20 g/L. The lowering of acetic acid content indicated the inhibition of acid buildup. Values of the coefficient of retention for all of the examined quality parameters, except turbidity, suggested that the overall influence of microfiltration was moderate.

This study examined the application of mathematical models on total flavonoids content and sensory mark of kombucha beverages on winery effluent. Process parameters were as follows: 0, 3, 6 and 9 days of fermentation time; 20, 25 and 30 ?C of fermentation temperature and 3, 5 and 7% of initial total reducing sugars. Total flavonoids were determined spectrophotometrically and sensory mark by a descriptive test and five points category scale. Total flavonoids content decreased during the applied kombucha fermentation process, which lasted for 9 days. On average, total sensory mark suggested that consume kombucha products are obtained after 3 days of the fermentation, regardless on the fermentation temperature or sugars content. In order to produce kombucha beverage with the highest bioactive quality, response surface methodology proposed the following process parameters: 3 days of fermentation, 7% of initial total sugars and 30?C process temperature.

Determination of sugar, nitrogen, and phosphorus consumption by kombucha culture is necessary to gain additional insight into the kombucha metabolic pathways and nutritional value of the produced beverages and to set a basis for optimizing the conditions for large-scale production. Kombucha beverage was made using effluent obtained from grape must clarification phase of white wine production. The fermentation medium was prepared by diluting the sterilized initial medium with approximately 16% of total reducing sugars to 3, 5, and 7% of total reducing sugars. The duration of the fermentation was nine days at 20, 25, and 30 degrees C. Sugars, nitrogen, and phosphorus content were measured using DNS, Kjeldahl, and molybdenum blue methods, respectively. The highest sugar content was in the initial medium (16.34%) and the lowest was after nine days of fermentation at 30 degrees C with 3% initial sugar content (0.17%). Residual levels of sugars, nitrogen, and phosphorus after three days were modeled using response surface methodology. The proposed mathematical models for sugars and nitrogen content showed an exceptional correlation with the experimentally obtained values. With this study insight into kombucha's consumption of basic nutrients, nutritional value of the obtained products, and optimization of product composition was provided.

Increasing consumer preference for natural and organic products, along with recognition of the multifunctionality and health benefits of vinegar, are key drivers of the global vinegar market growth. This growing demand gives vinegar producers a great opportunity to diversify their product offerings. In this study, the possibility of kombucha vinegar production on sucrose-sweetened black tea and infusions based on different herbs (peppermint, chamomile, stinging nettle, thyme, echinacea, lemon balm, yarrow, lavender, basil, and valerian) through prolonged fermentation by the autochthonous symbiotic culture of bacteria and yeasts was examined. The fermented media were analyzed regarding bioprocess success indicators to determine the fermentation capability of the used kombucha culture under the applied conditions. The quality of the obtained products was evaluated based on their chemical composition, bioactivity, and sensory properties. All experimental data were statistically processed to establish the effect of the medium composition variation on the prolonged kombucha fermentation efficacy. Summarizing all the results and findings, the basil was selected as the herb with the greatest utilization potential in the production of herbal kombucha vinegar, an innovative food product with promising health-promoting effects. The basil-based kombucha product created in this study is an acidic product (pH value of 2.66) rich in nutrients and bioactive compounds (sugars content of 32.78 g/L, total acids content of 55.52 g/L, total phenols content of 29.32 mg GAE/L, vitamin C content of 3.85 mg/L, RSCDPPH of 85.59 %, and RSCABTS of 58.89 %), and with highly acceptable sensory quality (mean liking scores for the evaluated sensory attributes >= 8.3).

This study further examined the biological potential of winery effluent based kombucha products. The antioxidant compounds and antioxidant potential of obtained kombucha samples were determined. In order to establish the most suitable fermentation parameters the kombucha fermentation process was performed at 20, 25 and 30 °C on the winery effluent substrate with 3, 5 and 7

This chapter provides a literature overview of the formation of the volatile compounds in different types of kombucha beverages. Traditionally, kombucha is cultivated on sweetened black or green tea at room temperature. The application of other substrates and fermentation process parameters widened the range of kombucha products. Nowadays, herb- and milk-based kombucha beverages, products obtained by fermentation of spices, winery effluent, fruits, and flowers are also available. Basic facts about kombucha history, production, microbiological and chemical composition, as well as physiological properties, are described. The formation of acetic acid, ethanol, and other volatiles is explained. Volatile components are the major part of the formation of sensory attributes. Acetic acid is the dominant volatile compound responsible for the kombucha beverage’s sour taste and antimicrobial activity. Most of the kombucha research demonstrated a low level of ethanol, which classifies these products as soft drinks. This is in accordance with the fact that kombucha fermentation is an aerobic process.

Kombucha beverage was produced using effluent from clarifying the grape must. Substrate for fermentation was prepared by diluting sterilized winery effluent to 70, 50, and 30 g/L of total sugars. Fermentation lasted for nine days at 20, 25, and 30 degrees C. A pleasant taste kombucha was produced. The beverage was ready to drink after three days of fermentation. From 300 mL fermentation volume, more than 40 g/L of biomass was produced at maximum temperature and sugar content. Acetic acid was the acid, with a peak concentration of 14.63 g/L after nine days at 30 degrees C and 70 g/L. Tartaric acid originated from the grape. Oxalic acid content was higher at the lower fermentation temperature. Produced kombucha had good antimicrobial properties. Higher temperature and sugar content promote antimicrobial activity against both Gram-positive and Gram-negative bacteria. No activity against yeast was observed. Antimicrobial properties against bacteria and acetic, tartaric, and oxalic acids content were modelled using RSM. Correlation analysis showed a positive relationship between acetic and tartaric acid content and antimicrobial activity.

Milk-based kombucha beverages were obtained conducting kombucha lead fermentation of milk. In order to discriminate the analysed samples and to detect similarities or dissimilarities among them in the space of experimentally determined variables, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied. Linear discriminant analysis (LDA) was conducted on the raw data set in order to find a rule for allocating a new sample of unknown origin to the correct group of samples. In the space of the variables analysed by HCA, the dominant discriminating factor for the studied samples of kombucha beverages is the milk fat (MF) content, followed by total unsaturated fatty acids content (TUFA), monounsaturated fatty acids content (MUFA) and polyunsaturated fatty acids content (PUFA). The samples with 0.8 and 1.6% milk fat belong to the same cluster in the space of the analysed variables due to similarities in their AA(DPPH). It was determined by LDA that there was the biggest difference in quality between the groups of products with winter savoury and stinging nettle, while the highest similarity is between groups of products with wild thyme and peppermint regarding their pH values and antioxidant activity expressed as AA(DPPH).

Bioactive properties, as well as chemical composition and sensory characteristics of traditional and alternative kombucha broths were examined. Samples were produced by adding 10% of kombucha starter to sweetened (7% sucrose) decocts of black and green teas (traditional substrates) and infusions of winter savory (Satureja montana), peppermint (Mentha?piperita), stinging nettle (Urtica dioica), wild thyme (Thymus serpyllum), elderberry (Sambucus nigra) and quince (Cydonia oblonga), at 25?C. Fermentation lasted the shortest with elderberry (3 days) and the longest with quince (10 days). The samples with black tea and peppermint had the best sensory quality. In general, alternative products had better antioxidant activity to hydroxyl radicals than the traditional ones, reducing power and angiotensin-converting enzyme inhibitory activity. The most pronounced acetic acid content was obtained with elderberry substrate. Moreover, peppermint substrate showed the highest values both for total phenols and total flavonoids contents. Taken together, the samples produced with the alternative substrates highlighted a higher phenolic and flavonoid contents, compared to the ones obtained with the traditional substrates.

Kombucha beverage is a fermented product obtained by kombucha culture fermentation of, usually, black or green tea. Besides black and green tea, kombucha also ferments water extracts of medicinal herbs. The obtained products possess antioxidant activity. The aim of this paper was to establish the antioxidant potential of kombucha beverages with black tea, green tea, and medicinal herbs after pepsin and pancreatin in vitro digestion. The radical scavenging ability of DPPH and hydroxyl radical, as well as reducing power of kombucha products was determined. At the end of the digestion process, the highest antioxidant potential towards hydroxyl radical showed only kombucha beverages with peppermint and stinging nettle extract. Results for reducing power and antioxidant capacity to scavenging DPPH radical showed a decrease in values after the digestion process.

Effluent from clarifying the must from wine production was used as a sole medium for kombucha fermentation. Usually, this effluent is disposed in the communal sewage system. This way of use and treating wastewater is certainly ecologically beneficial. The initial substrate for cultivation was prepared by diluting sterilized winery effluent to 70 g/L of total sugars, using boiled tap water. Kombucha starter was prepared using black tea and sucrose and added 10% (vol/vol) to the initial substrate. Fermentation was performed at 25 degrees C. The obtained beverage was appropriate for consummation after 6 days. Obtained kombucha product had an enjoyable taste with wine alike note. The produced beverage had supreme DPPH radical scavenging ability and reducing power compared to traditional black- and green- tea based kombucha. Hydroxyl radical scavenging ability was also significant. A variety of organic acids was detected. Ascorbic acid content was 3.6 mg/L on the consumption day. Practical applications Using winery wastewater this way provides benefits for both winemakers and kombucha producers. Winemakers eliminate effluent with a lot of organic compounds for free and kombucha producers ensure raw material for the fermentation. An additional benefit is the eco-friendly disposal of wastewater that generally goes to communal sewerage.

Variation of bioactive compounds content of fermented cabbage hybrid "Bravo" heads were investigated in the present study. The fermentation process was carried out under industrial conditions using combinations of NaCl content (60, 70, 80 g/kg), starter culture Lactobacillus plantarum 14D (0, 0.025, 0.050 g/kg) and temperature (18, 22, 26 degrees C). The cabbage sample obtained under conditions (60 g/kg, 0 g/kg, 22 degrees C) was taken as a referent. Samples were analysed after 5, 12, 27, 62 days in order to measure antioxidant activity, ascorbic, oxalic, acetic, formic, lactic, and succinic acid content. Sum of ranking differences and hierarchical cluster analysis for determination of optimal fermentation conditions in terms of antioxidant activity and ascorbic acid content were applied. During the fermentation pH was monitored and the results after 12 days, 4.37-3.51, proved to be the most suitable. Additionally, antioxidant activity reached its maximum after 12 days of cabbage fermentation, in general. The best result was obtained for the sample (60 g/kg, 0.050 g/kg, 22 degrees C) after 12 days of fermentation with highest value of antioxidant activity 16.09 mg/mL, while content of ascorbic, oxalic, acetic, formic, lactic and succinic acid amounted, 2.97, 13.39, 0.77, 1.21, 7.58 and 0.48 g/100 g dry matter, respectively.

The aim of this paper was ethanol content determination in kombucha products obtained by fermentation of effluent from white wine production. Used substrate contained 5% of total sugars and production process was conducted at 20, 25 and 30?C. Ethanol was determined by volumetric method common for ethanol determination in refreshing non-alcoholic beverages. Winery effluent was successfully applied in kombucha fermentation process. Results indicated that the produced kombucha beverages are suitable for human consumption as non-alcoholic beverages. Only products obtained at 30?C (the sixth day) and at 20?C (the sixth and the ninth day) do not belong to the group of non-alcoholic beverages. Certain process parameters were established in order to produce suitable kombucha product.

In this work, pumpkin seed oil cake that remains after process of cold pressed oil extraction, was used for the production of composite biopolymer based packaging films. During the production of films, four degrees of filtration were applied. The obtained composite biopolymer films were analyzed for antioxidant activity using three different antioxidant activity assays: the ability to capture free radicals, including •DPPH radical and hydroxyl radical, •OH, as well as reduction power assay of the analyzed films. By comparing the antioxidant activity of the films obtained with different degrees of filtration, it can be concluded that the films obtained by finer filtration (smaller diameter of the filter pore) exhibit greater ability to capture •DPPH radicals, as well as higher reducing power, while the ability to capture hydroxyl radicals showed different trend. Films obtained from the coarser filtered fractions (higher diameter of the filtrate medium) showed greater •OH scavenging ability.

Active films based on pumpkin oil cake, with 1 % and 2 % of winter savory and basil essential oil, were synthesized in the paper, and the antioxidant activity of the films obtained was subsequently examined. A biopolymer film based on pumpkin oil cake without the addition of essential oils was used as a control. The following methods were used for determining the antioxidant activity of the films: the DPPH radical scavenging activity, the hydroxyl radical scavenging activity and the reducing power assay. The control film showed some antioxidant activity (DPPH radical scavenging activity = 61 %, hydroxyl radical scavenging activity = 33 %, reducing power = 0.534). However, the addition of essential oils increased the antioxidant activity of the films, especially their reducing power, where as the film with 2 % of winter savory essential oil exhibited the highest activity. A slight increase in the DPPH radical and the hydroxyl radical scavenging activities was also observed with the incorporation of essential oils into the experimental films.