Impact of time and temperature on the physicochemical, microbiological, and nutraceutical properties of laver kombucha (Porphyra dentata) during fermentation

Microbiological characterization of kombucha and biocellulose film produced with black tea and cocoa bean shell infusion

The food industry is increasingly striving to produce probiotics-based food and beverages using sustainable processes. Therefore, the use of by-products in product development has been investigated by several authors. The aim of this work was to investigate the effects of cocoa bean shell infusion in the production of kombucha through microbiological and genetic characterization. Three beverage formulations were prepared, one based on black tea (KBT), one based on cocoa bean shell infusion (KCS) and one containing 50 % black tea and 50 % cocoa shell infusion (KBL). The infusions were prepared with water, filtered, and sucrose was added. They were then homogenized and a portion of finished kombucha and SCOBY (symbiotic culture of bacteria and yeast) were added. Fermentation took place for 13 days and aliquots were collected every three days for physicochemical and microbial count analyses. Samples from the last day of fermentation were sent for DNA sequencing, extraction and quantification. The results were subjected to analysis of variance and compared by using Tukey's test (p < 0.05). The results show that there was a significant decrease in pH over time in all samples, while the titratable acidity increased, indicating an acidification of the beverage due to the production of organic acids. There was an increase in lactic acid bacterial colonies in all the formulations, which have a probiotic nature and are not always found in this type of beverage. Regarding the taxonomic classification of the samples, microorganisms of the kingdoms Fungi and Bacteria, of the families Saccharomycetaceae and Acetobacteraceae, were found in KBT, KCS and KBL, but with different microbiological compositions, with different amounts of yeasts and bacteria. Therefore, the use of by-products such as cocoa bean shell in the production of kombucha can contribute to the reduction of waste in the food industry and, at the same time, accelerate fermentation increasing the presence of lactic acid bacteria when compared to black tea.

Kombucha as a Health-Beneficial Drink for Human Health

Kombucha is a unique fermented beverage made from a symbiotic culture of yeast and bacteria. Kombucha is normally based on black tea added to water, then sugar is added as a substrate for fermentation in this beverage. This unique beverage is composed of amino acids, flavonoids, vitamins, and some active enzymes. Several beneficial health effects such as antioxidant, antimicrobial effects have been reported as a result of probiotics and prebiotics presence. These health effects of kombucha are attributed to its bioactive chemical and biological agents of probiotics bacteria e.g., Gluconobacter, Acetobacter and yeasts like Saccharomyces sps., along with glucuronic acid as the main sources of the health protection. This review focuses on the beneficial effects of Kombucha including antimicrobial, antioxidant, anti-cancer antidiabetic properties, as well as liver protection, treat of gastrointestinal problems, AIDS, gastric ulcers, obesity (and energy production), detoxification, and skin health.

Research progress on alternative kombucha substrate transformation and the resulting active components

Kombucha is a customary tea-based beverage that is produced through the process of fermenting a mixture of tea and sugar water with symbiotic culture of bacteria and yeast (SCOBY). Traditional kombucha has various beneficial effects and can improve immunity. The significant market share of Kombucha can be attributed to the growing consumer inclination towards healthy foods within the functional beverage industry. The research focus has recently expanded from the probiotics of traditional black tea kombucha to encompass other teas, Chinese herbs, plant materials, and alternative substrates. There is a lack of comprehensive literature reviews focusing on substance transformation, functional, active substances, and efficacy mechanisms of alternative kombucha substrates. This article aimed to bridge this gap by providing an in-depth review of the biological transformation pathways of kombucha metabolites and alternative substrates. The review offers valuable insights into kombucha research, including substance metabolism and transformation, efficacy, pharmacological mechanism, and the purification of active components, offering direction and focus for further studies in this field.

Kombucha: Challenges for Health and Mental Health

BACKGROUND

Increasing research into probiotics is showing potential benefits for health in general and mental health in particular. Kombucha is a recent beverage and can be considered a probiotic drink, but little is known about its effects on physical and mental health. This product is experiencing growth in the market; however, there are no scientific results to support its potential for physical and mental health.

AIM

This review article aims to draw attention to this issue and to highlight the lack of studies in this area.

KEY FINDINGS AND CONCLUSIONS

The lack of legislation for the correct marketing of this product may also constrain clinical studies. However, clinical studies are of utmost importance for an in-depth understanding of the effects of this product on the human body. More research is needed, not only to better understand the impact of Kombucha on the human body, but also to ensure the application of regulatory guidelines for its production and marketing and enable its safe and effective consumption.

Sucrose Concentration and Fermentation Temperature Impact the Sensory Characteristics and Liking of Kombucha

Kombucha is a fermented tea beverage consumed for its probiotics and functional properties. It has a unique sensory profile driven by the properties of tea polyphenols and fermentation products, including organic acids. Fermentation temperature and sucrose content affect the fermentation process and the production of organic acids; yet less is known about their impacts on the sensory profile and consumer acceptance. Thus, we aimed to examine the impact of sucrose concentration and fermentation temperature on sensory attributes and liking. For this study, kombucha tea was fermented at three different concentrations of sucrose and fermented at two temperatures for 11 days. Fermentation was monitored by pH, brix, and titratable acidity, and consumers (n = 111) evaluated the kombucha for sensory attributes and overall liking. The fermentation temperature resulted in significant differences in titratable acidity, with higher temperatures producing more organic acids, resulting in higher astringency, and suppressed sweetness. The lower fermentation was reported as significantly more liked, with no difference in liking between the 7.5% and 10% sucrose kombucha samples. Fermentation temperature had the greatest impact on the sensory profile rather than sucrose concentration, which had a greater effect on the fermentation rate and production organic acids.

Microbiological and Physico-Chemical Characteristics of Black Tea Kombucha Fermented with a New Zealand Starter Culture

Kombucha is a popular sparkling sugared tea, fermented by a symbiotic culture of acetic acid bacteria (AAB) and yeast. The demand for kombucha continues to increase worldwide, mainly due to its perceived health benefits and appealing sensory properties. This study isolated and characterised the dominant AAB and yeast from a starter culture and kombucha broth after 0, 1, 3, 5, 7, 9, 11, and 14 days of fermentation at ambient temperature (22 °C). Yeast and AAB were isolated from the Kombucha samples using glucose yeast extract mannitol ethanol acetic acid (GYMEA) and yeast extract glucose chloramphenicol (YGC) media, respectively. The phenotypic and taxonomic identification of AAB and yeast were determined by morphological and biochemical characterisation, followed by a sequence analysis of the ribosomal RNA gene (16S rRNA for AAB and ITS for yeast). The changes in the microbial composition were associated with variations in the physico-chemical characteristics of kombucha tea, such as pH, titratable acidity, and total soluble solids (TSS). During fermentation, the acidity increased and the TSS decreased. The yield, moisture content, and water activity of the cellulosic pellicles which had developed at the end of fermentation were attributed to the presence of AAB. The dominant AAB species in the cellulosic pellicles and kombucha broth were identified as Komagataeibacter rhaeticus. The yeast isolates belonged to Debaryomyces prosopidis and Zygosaccharomyces lentus.

Kombucha Beverages Produced from Fruits, Vegetables, and Plants: A Review on Their Pharmacological Activities and Health Benefits

Kombucha is a traditional health beverage produced by fermenting sweetened tea with a symbiotic culture of bacteria and yeasts. Consumption of kombucha beverages has been growing and there is kombucha commercially available worldwide as one of the most famous low-alcohol beverages. Kombucha beverages have been claimed to have beneficial effects on human health because they contain a variety of bioactive compounds that possess various functional properties. At present, several kinds of raw material (e.g., milk, fruit, vegetables, and herbs) have been fermented with kombucha consortium and consumed as kombucha beverages. Although several studies have been written regarding the biological activities of kombucha and raw materials, there is however little information available on the characterization of their components as well as the biological activities of fermented kombucha from many raw material mixtures. Several pharmacological activities were reviewed in the scientific literature, describing their potential implications for human health. In addition, the adverse effects and toxicity of kombucha consumption were also reviewed. In this study, we focused on the main and latest studies of the pharmacological effects of kombucha beverages produced from various kinds of raw materials, including antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, anticancer, antidiabetic, antihypertensive, and antihyperlipidemic effects in in vitro and in vivo studies.

Application of environmental-safe fermentation with Saccharomyces cerevisiae for increasing the cinnamon biological activities

The effect of fermentation by Saccharomyces cerevisiae on biological properties of cinnamon (Cinnamomum cassia) was investigated. The study demonstrated that the extract of S. cerevisiae-fermented cinnamon (S.C.FC) has antioxidants higher than non-fermented one. The optimum results for antioxidant yield were noted with 107 CFU S. cerevisiae/10 g cinnamon and 70 mL of dH2O at pH 6 and incubated for 3 d at 35 °C. Under optimum conditions, ABTS, DPPH, and H2O2 radical-scavenging activity increased by 43.8, 61.5, and 71.9%, respectively. Additionally, the total phenols and flavonoids in S.C.FC were increased by 81.3 and 415% compared by non-fermented one. The fermented cinnamon had antimicrobial activity against L. monocytogenes, S. aureus, E. coli, S. typhi, and C. albicans. Also, the anti-inflammatory properties were increased from 89 to 92% after fermentation. The lyophilized extract of S.C.FC showed positive effect against Huh7 cancer cells which decreased by 31% at the concentration of 700 µg/mL. According to HPLC analysis, p-hydroxybenzoic acid, gentisic acid, catechin, chlorogenic acid, caffeic acid, and syringic acid were increased by 116, 33.2, 59.6, 50.6, 1.6, and 16.9%, respectively. Our findings suggest the applicability of cinnamon fermentation using S. cerevisiae as a useful tool for processing functional foods to increase their antioxidant and anti-inflammatory content.

Bioinformatic Prediction and Characterization of Proteins in Porphyra dentata by Shotgun Proteomics

Porphyra dentata is an edible red seaweed with high nutritional value. It is widely cultivated and consumed in East Asia and has vast economic benefits. Studies have found that P. dentata is rich in bioactive substances and is a potential natural resource. In this study, label-free shotgun proteomics was first applied to identify and characterize different harvest proteins in P. dentata. A total of 13,046 different peptides were identified and 419 co-expression target proteins were characterized. Bioinformatics was used to study protein characteristics, functional expression, and interaction of two important functional annotations, amino acid, and carbohydrate metabolism. Potential bioactive peptides, protein structure, and potential ligand conformations were predicted, and the results suggest that bioactive peptides may be utilized as high-quality active fermentation substances and potential targets for drug production. Our research integrated the global protein database, the first time bioinformatic analysis of the P. dentata proteome during different harvest periods, improves the information database construction and provides a framework for future research based on a comprehensive understanding.

Metabolite profiling and pathway prediction of laver (Porphyra dentata) kombucha during fermentation at different temperatures

This study is aimed to explore the impact of fermentation temperature on laver kombucha by profiling the accumulation and degradation of metabolites and elucidating their related pathways of metabolism. Laver kombucha was produced through ultrasound-assisted extraction and fermentation using a biofilm called SCOBY at 25 and 30 °C (hereafter named K-25 and K-30, respectively) for 14 days. Overall, organic acids, soluble sugars, amino acids, and phenolic compounds were found to participate in the biosynthesis pathway. The level of amino acids showed a decreasing trend, except taurine in the K-30. At day 14, phenolic compounds (pyrogallol, ρ-hydroxybenzoic acid, ρ-coumaric acid, salicylic acid, rutin, and naringin) were accumulated in both samples. Although it showed a similar trend, K-25 exhibited a higher metabolite accumulation tendency than K-30. This comprehensive characterization of the dynamic changes of metabolites and pathway prediction can pinpoint the influence of the fermentation conditions on the biosynthesis of secondary metabolites.

Microbiological and Physicochemical Composition of Various Types of Homemade Kombucha Beverages Using Alternative Kinds of Sugars

Kombucha is a beverage made by fermenting sweetened tea with a symbiotic culture of yeast and bacteria. Literature data indicate that the kombucha beverage shows many health-promoting properties such as detoxification, chemo-preventive, antioxidant, antimicrobial, antifungal, and general strengthening. The research conducted focuses on the analysis of polyphenolic compounds formed in the fermentation process using ultra-efficient liquid chromatography, as well as on checking the antimicrobial properties of kombucha against pathogenic bacteria and yeasts found in food. Analysis of the composition of the tea mushroom (SCOBY) microflora using the MALDI TOF MS Biotyper mass spectrometer showed 8 species of bacteria and 7 species of yeasts. In vitro studies confirm the bactericidal and bacteriostatic properties of fermented kombucha beverages, with white and green tea beverages showing the highest antibacterial activity. The bacteria Staphylococcus aureus and yeast Candida albicans were the most sensitive to the effects of kombucha tea beverages. UPLC chromatographic analysis confirmed the presence of 17 bioactive compounds in kombucha beverages that can affect human health. The analyses conducted were aimed at indicating the best recipe and conditions to prepare a kombucha beverage, which allowed the selection of the version with the best health-promoting properties. Fermented kombucha teas contain many elements such as aluminium, calcium, iron, potassium, magnesium, sodium, phosphorus, and sulphur.

Kombucha analogues around the world: A review

Kombucha is a traditional healthy beverage usually made by the fermentation of sweetened tea with a symbiotic culture of bacteria and yeast. The consumption of kombucha is associated with numerous health benefits and therefore the beverage has attracted the attention of consumers worldwide. Non-typical substrates (fruits, vegetables, plants, herbs, dairy, and by-products) are being inoculated with the kombucha consortium in an attempt to develop new products. This review paper reviews the fermentation parameters for different non-tea substrates used to make kombucha, in addition to the findings obtained in terms of physico-chemical analysis, biological activities and sensory evaluation.