How Water Chemistry Affects the Production and Flavor Profile of Kombucha and Other Fermented Beverages

Acetic acid bacteria (AAB) have, for centuries, been important microorganisms in the production of fermented foods and beverages such as vinegar, kombucha, (water) kefir, and lambic beer. Their unique form of metabolism, known as "oxidative" fermentation, mediates the transformation of a variety of substrates into products, which are of importance in the food and beverage industry and beyond; the most well-known of which is the oxidation of ethanol into acetic acid. Here, a comprehensive review of the physiology of AAB is presented, with particular emphasis on their importance in the production of vinegar and fermented beverages. In addition, particular reference is addressed toward Gluconobacter oxydans due to its biotechnological applications, such as its role in vitamin C production. The production of vinegar and fermented beverages in which AAB play an important role is discussed, followed by an examination of the literature relating to the health benefits associated with consumption of these products. AAB hold great promise for future exploitation, both due to increased consumer demand for traditional fermented beverages such as kombucha, and for the development of new types of products. Further studies on the health benefits related to the consumption of these fermented products and guidelines on assessing the safety of AAB for use as microbial food cultures (starter cultures) are, however, necessary in order to take full advantage of this important group of microorganisms.

This study was designed to valorize dairy byproducts including cheese whey and buttermilk through developing fermented beverages using a novel isolated Apilactobacillus kunkeei EABW06 strain from Egyptian bee's wax. Cheese whey or buttermilk was fermented with A. kunkeei and compared to fermented whey or buttermilk supplemented with Rutab date pulp on day one or after 15 days of cold storage. Physicochemical, microbiological, sensory, proteolytic, and various functional properties were investigated. Fermented buttermilk beverages particularly supplemented with date pulp had the highest viscosity and water-holding capacity at the beginning or after 15 days of cold storage. The supplementation with date pulp led to increase the viable count of A. kunkeei. Compared to fermented whey beverages, fermented buttermilk beverages recorded the greatest scores of sensory attributes. The proteolytic, ACE-I, and antioxidant activity enhanced in fermented buttermilk supplemented with or without date pulp. A storage period exhibited a positive effect on the proteolysis, ACE-I, and DPPH radical scavenging properties of fermented beverages. All fermented beverages showed a great inhibitory impact against the growth of various species of fungi and bacteria. Fermented buttermilk beverages demonstrated the highest cytotoxicity against Caco2 cell lines with IC50 values of 81.22-86.89 μg/mL. However, fermented whey beverages had the strongest inhibition of α-amylase and α-glucosidase enzymes. These findings propose that whey or buttermilk serves as an effective medium for the growth of A. kunkeei and potentially enabling the development of innovative fermented dairy beverages with beneficial health effects.

Kombucha is a beverage made by fermenting sweetened brewed tea (substrate) by symbiotic culture of yeast and bacteria. Numerous researches on optimization of fermentation process, determination of the influence of technological factors on physical and chemical properties, formation of taste and flavor profile of the beverages, prevention of industrial product risks are due to the growing popularity of kombucha in Europe and the USA. Technological features of kombucha production are to optimize conditions for the growth of symbiotic culture and substrate fermentation. The duration of the process depends on the composition of the substrate, the ratio of tea mushroom and substrate, temperature, size and shape of fermentation vessel. The aim of the work was to generalize the results of studying the technological features of the production of fermented kombucha type beverages and to identify the factors that affect the chemical composition and safety of the finished beverages. Material and methods. Analytical research was carried out on the main databases for the keyword "kombucha". The criteria for inclusion of articles in the analysis were research articles with open access and presenting detailed technology of kombucha. Results. The technology of kombucha production is based on fermentation of the substrate and obtaining the base of the beverage with high content of organic acids, mainly acetic acid. In order to ensure microbiological safety the acetic acid concentration in the beverage base must be at least 1.2%. The high organic acid content necessitates the use of only glass or stainless steel fermentation equipment approved for food contact. The fermentation temperature ranges from 18 to 32 °C. The fermentation process is monitored according to basic criteria: temperature, pH value, acidity, acetic acid content, ethyl alcohol content, and residual sugar content. Kombucha production process is connected with microbiological, chemical and physical risks which could appear in case of using low quality raw materials, equipment and consumer packaging made of materials which do not correspond to sanitary norms, violating technological regimes, storage conditions of raw materials and ready production. To prevent hazards affecting the quality and safety of the finished product, it is necessary to control the technological process at all stages of production. Conclusion. Following sanitary-hygienic norms and technological regimes allows producing kombucha with a balanced taste and aroma, which meets the safety requirements for fermented beverages.

A special drop: Characterising yeast isolates associated with fermented beverages produced by Australia's indigenous peoples.

O processamento de frutas para a obtenção de bebidas é uma forma de agregar valor a essa matéria-prima e remunerar melhor o produtor rural por meio do aumento de demanda. Tendo essa ideia como premissa, o objetivo deste trabalho foi produzir fermentados de acerola e caracterizá-los físico-química e sensorialmente. A produção das bebidas foi baseada na legislação brasileira de fermentado de fruta e de vinho. Os fermentados foram produzidos a partir de suco (prensa) e polpa (despolpadora) de acerola, e adoçados com açúcar para a obtenção de três tipos de bebidas: seco, meio seco e suave. As bebidas foram analisadas físico-quimicamente quanto a pH, teor alcoólico, açúcar redutor, açúcar redutor total, acidez total, acidez volátil, acidez fixa, extrato seco, extrato seco reduzido, relação álcool/extrato seco reduzido, dióxido de enxofre livre, dióxido de enxofre total e turbidez. A análise sensorial das bebidas foi feita pelo teste de escala hedônica estruturada de nove pontos, sendo considerados aparência, odor, sabor e avaliação global. Os resultados das análises físico-químicas e sensorial foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey (significância de 5%). Tanto as matérias-primas (suco e polpa) como as diferentes concentrações de açúcar (seco, semisseco e suave) interferiram nos parâmetros físico-químicos e sensoriais dos fermentados de acerola, sendo que os provadores demonstraram preferência pelas bebidas mais adocicadas.

Many indigenous fermented foods and beverages consumed throughout the world are produced at home or in crafts enterprises. The production of fermented beverages on a large commercial or industrial scale requires clearly established technical and technological requirements. This study shows a novel way to investigate the optimal process parameters of the Kyrgyz traditional fermented beverage Bozo using rotational rheological parameters. Five significant process parameters were investigated like cooking of millet porridge, the mashing temperature, the mashing time under conditions of mixing and viscosity changes of the end product during storage. According to the gelatinization temperature of millet porridge, cooking parameters were recommended at T = 79°C and t = 30min. The optimum mashing temperature of millet porridge was determined to be 65°C and mashing time under stirring conditions of millet porridge was found to be 10min. The viscosity of the beverage Bozo was investigated after 7, 14 and 21days of storage at 5, 10, 20, and 30°C. The effective viscosity of Bozo was calculated using the Casson model, which increased from 39.67 to 51.25Pa·s after 21days of storage. The effect of temperature on effective viscosity of Bozo and the activation energy was calculated using an Arrhenius-type equation. The parameters obtained make it possible to provide food manufacturers useful information for boiling, mashing and storage parameters after fermentation as well as quality control of Bozo.

The production of fermented beverages is a promising way to valorize by-products of dairy manufacturing. However, the shelf-life of these products is often limited by the post-acidification process that occurs during storage. In this work, we manufactured a fermented beverage from sweet whey by using the starter lactic acid bacteria (SLAB) Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. High-pressure processing (HPP) at 200 MPa for 10 min or 400 MPa for 1 min were applied after manufacturing. The aim of this study was to evaluate the effect of HPP on the quality of the beverage and on the behavior of the SLAB. Both high hydrostatic pressure treatments preserved flavor and texture attributes until 45 days post-HPP, without affecting chromatic parameters. Plate counts for both species were lower in HPP-treated beverages (HB) than in control beverages (CB), although treatment at 200 MPa maintained optimal amounts of total SLAB (6.6–7.9 log CFU/mL). Conversely, quantitative PCR (qPCR) and reverse transcription-qPCR (RT-qPCR) revealed that bacterial DNA or mRNA levels persisted after HPP (> 1.4 × 105 genome or cDNA copies/mL), even upon 400-MPa treatments. As a whole, this study indicated that HPP preserved the quality of the beverage until 45 days post-HPP, which is longer than the shelf-life of conventional fermented beverages obtained from milk. Moreover, our results obtained with these SLAB in a fermented dairy beverage upon HPP extend previous findings regarding the limitations of culture-dependent methods to assess microbial viability.

Los Ríos province is eminently agricultural since the main activity of its population is the product cultivation such as cocoa, coffee, soy, passion fruit and others. Two cacao varieties are cultivated: the Nacional (delicate aroma) and the CCN51. The increase in cocoa production in the Los Ríos province has generated a large amount of waste (mucilage). Much of the cocoa mucilage is eliminated in the drainage systems, discarding a product with a high content of sugars and beneficial yeasts for fermentation processes. Due to this, the work aims to analyse the use of cocoa mucilage CCN-51 or Nacional in the production of fermented beverages that allow obtaining an added value of the surpluses of cocoa production. The methodology consisted first of the approach of design combinations (with eight experimental units and three repetitions) for fermented beverage elaboration. Then, these combinations were analysed with physicochemical parameters (pH, °Brix, °GL, transmittance, absorbance, and suspended solids) and with organoleptic analyses (product tasting). As a result, the fermented carambola beverage showed better physicochemical characteristics. Of the eight experimental units, number 8 (carambola + mucilage concentration 15% + national variety) presented better results; with transmittance values of 38.40%, suspended solids 0.0061%, density 0.978 kg/m3, alcoholic degrees 16.67 °GL, acidity 0.48 g/L and pH 3.66. Also, the organoleptic results obtained an excellent acceptance thanks to the good colour, smell, taste, sweetness, and low astringency. This allowed having another alternative/solution for discarded mucilage use in Los Rios province.

The production of plant-based fermented beverages has been currently focused on providing a functional alternative to vegan and/or vegetarian consumers. This study primarily targeted the development and characterization of fermented beverages made up of hydrosoluble extracts of oats, almonds, soybeans, Brazil nuts, and rice. The fermentation was carried out by lactic cultures of Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, and Streptococcus thermophilus. Plant extracts were fermented at 37 °C for 12 h, with and without sucrose supplementation. The physicochemical and microbiological stability of the extracts was monitored for 28 days at 5 ± 1 °C. The composition of the fermented beverages was subsequently determined. The pH values measured at the beginning and the end of the extracts' fermentation ranged between 6.45 and 7.09, and 4.10 to 4.97, respectively. Acidity indices, expressed as a percentage of lactic acid, ranged from 0.01 to 0.06 g/100 mL at the beginning of the fermentation, and from 0.02 to 0.33 g/100 mL upon fermentation being concluded. Most fermented extracts achieved viable lactic acid bacteria counts exceeding 106 CFU/mL during storage. Sucrose supplementation did not alter the rate of bacterial growth. The findings showed that the complete replacement of dairy ingredients with water-soluble plant extracts is a potential alternative for developing a functional fermented plant-based beverage.

6 - Mexican traditional alcoholic beverages: Production process, history, economy, social, and scientific importance

This study aimed to point out the possible use of oak leaves (Q. petraea) in the production of fermented alcoholic beverages. Parameters such as antioxidant capacity, total phenolic content, phenolics and sugars were determined using spectrophotometric and chromatographic methods. pH values were also determined, and in the final product with a fermentation length of 85 days, the alcohol content was determined and sensory analysis performed. The antioxidant capacity of the beverage was lower compared to the infusions before fermentation, and its highest values were recorded in the leaf samples, in which the highest values of phenolic compounds and the total phenolic content were also recorded. A decrease in the content of total phenolics was recorded with the increasing length of fermentation in beverage samples. However, the fermentation process had a positive effect on the contents of some phenolic substances such as catechin, gallic acid and gallocatechin. Sensory analysis showed a higher acceptability of the fermented beverage without the addition of orange, which could be caused by the higher sugar content in these samples. Oak leaves therefore represent a suitable raw material for the production of a fermented alcoholic beverage, without the need to enrich the taste with other ingredients.

The article is devoted to the food industry topical issue – the production of fermented beverages of plant origin. Based on the literature analysis, the main types of fermented non-dairy products and raw materials for their production have been described. The distribution of traditional fermented alcohol-free drinks has been shown and the connection with the typical raw materials of production has been established. The review introduces the inherent microbiota of such well-known drinks as kombucha, kvass, and boza. The symbiotic interactions between bacteria and yeast, which are typical microbial representatives of these beverages, have been described. The impact of microbial interactions on the quality and functional product characteristics, as well as their importance, have been analyzed. Probiotic properties of lactic acid bacteria isolated from fermented drinks have been presented. The presence of functional properties of raw materials used in beverages production, as well as the importance of fermentation processes, have been established. The typical biologically active metabolites inherent in many fermented beverages have been described. The main probiotic properties of lactic acid bacteria isolated from traditional fermented drinks have been highlighted. The issue of technological aspects of the common fermented drinks production has been considered. The importance of highlighting the typical microbiota representatives of beverages for further industrial use in food or therapeutic practice has been emphasized. The importance of the use of lactic acid bacteria in the fermented beverages production has been highlighted. The introduction of new methods and technologies, which will allow the production of functional fermented beverages with increased biological value, has been highlighted.

The tradition of making fermented foods and beverages in Iraq dates back to 7500 BC. These fermented foods and beverages are represented by meat-, milk-, vegetable-, and fruit-based products reflecting diversity of agricultural production in ancient Iraq (Mesopotamia). Although the recipes for some fermented foods and beverages were lost throughout history, those remaining foods and beverages occupy a noticeable position in modern Iraqi cuisine. In this review, knowledge and techniques for preparation of 5 traditional fermented foods, i.e. Basturma, Smoked Liban,Aushari cheese, Turshi, and Sour Khobz, and 3 fermented beverages, i.e. Shanina, Sharbet Zbeeb, and Erk Sous in Iraq, are documented. Traditional fermented foods and beverages have multiple health benefits because of high content of probiotics and bioactive compounds. Traditional fermented foods and beverages are made using the back-slopping technique which ensures safety of production and maintains organoleptic properties. The review highlights the potential of fermented foods and beverages for their large-scale commercialization.

During alcoholic fermentation, a number of desired products are produced on transformation of metabolites in the raw material used for fermentation. Among fermented alcoholic beverages, wine and beer are most popular, followed by other alcoholic beverages, such as cider, mead, sake, pulque, etc, which are comparatively less studied. These fermented beverages are rich in different types of bioactive compounds, which depend on the raw material. These alcoholic beverages contain vitamins and plant-derived bioactive compounds, such as phenolic acids, carotenoids, flavonoids, tannins, stilbenes, etc., which exhibit a wide range of human health benefits. The health benefits exhibited by bioactive compounds include antithrombotic, antimicrobial, anticancer, anti-ischemic, antioxidant, immunomodulatory and cholesterol-lowering effects. Apart from the raw material, the microorganisms associated with fermented alcoholic-beverage production also contribute to the functionality of the final product. The chapter describes the bioactive compounds in different fermented alcoholic beverages and their potential health benefits.

Rice, tiger nut and carob are Mediterranean products suitable for developing new foods, such as fermented beverages, due to their nutritional properties. These crops have a high carbohydrate content, are gluten and lactose-free and have a low allergenicity index. The development of fermented beverages from these crops can contribute to the Sustainable Development Goals by promoting human health and sustainable production and consumption. A narrative review of the nutritional value and potential functional activity of fermented beverages made from these crops was carried out. This literature review of existing studies on fermented and non-fermented beverages highlights their composition, production methodology, and health benefits. Fermented beverages made from these crops are high in fiber, essential fatty acids, vitamins (group B), and minerals. Fermentation increases the bioaccessibility of these nutrients while decreasing possible anti-nutritional factors. These fermented beverages offer several health benefits due to their antioxidant effects, modulating the intestinal microbiota and reducing the incidence of chronic degenerative diseases such as metabolic syndrome. Therefore, fermented rice, tiger nut and carob beverages can improve the Spanish diet by offering improved nutritional value and beneficial health effects. Additionally, these local crops promote sustainability, making them an appropriate choice for developing new fermented beverages.