Melatonin has recently been detected in fermented beverages and foods, in which microorganism metabolism is highly important. The existing literature knowledge discusses the direction for future ...studies in this review. Evidence shows that many species of microorganisms could synthesize melatonin. However, the actual concentrations of melatonin in fermented foods and beverages range from picograms per milliliter to nanograms per milliliter. Different types of microorganisms, different raw materials, different culture environments, the presence or absence of precursors, high or low alcohol content, and different detection methods are all possible reasons for the huge difference of melatonin levels. Thus far, there have been relatively few studies on the melatonin synthesis pathway microorganisms. Thus, referring to the synthetic pathway of plants and animals, the putative melatonin biosynthesis pathway of microorganisms is presented. It will be significant to discuss whether all species of microorganisms have the capacity to synthesize melatonin and what the biological functions of melatonin are in microorganisms. Melatonin plays a lot of important roles in microorganisms, particularly in enhancing the tolerance of environment stress. Also, the loss of melatonin concentration in commercially available fermented foods and beverages is a ubiquitous trend, and how to solve this problem is a new field to be further explored.
This study aimed to evaluate the hangover relieving effect of ginseng berry kombucha (GBK) fermented with Saccharomyces cerevisiae and Gluconobacter oxydans in in vitro and in vivo models. The ...antioxidant activity and oxidative stress inhibitory effect of GBK were evaluated in ethanol-treated human liver HepG2 cells. In addition, biochemical and behavioral analyses of ethanol treated male ICR mice were performed to confirm the anti-hangover effect of GBK. The radical scavenging activity of GBK was increased by fermentation, and the total ginsenoside content of GBK was 70.24 μg/mL. In HepG2 cells, in which oxidative stress was induced using ethanol, GBK significantly increased the expression of antioxidant enzymes by upregulating the Nrf2/Keap1 pathway. Moreover, GBK (15 and 30 mg/kg) significantly reduced blood ethanol and acetaldehyde concentrations in ethanol-treated mice. GBK significantly increased the levels of alcohol-metabolizing enzymes, including alcohol dehydrogenase and acetaldehyde dehydrogenase. The balance beam test and elevated plus maze test revealed that high-dose GBK significantly ameliorated ethanol-induced behavioral changes. Collectively, GBK exerted a protective effect against ethanol-induced liver damage by regulating the Nrf2/Keap1 pathway.
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•Lactobacillus was the most predominant bacterial genus in both Suansun and Suancai.•Kazachstania and Debaryomyces were dominant in both Suansun and Suancai.•Pichia and ...Zygosaccharomyces were the other two major fungal genera in Suansun.•Nakaseomyces was another major fungal genus in Suancai.•Salinity was the most important physicochemical factor affecting microbial profiles.
Guangxi Suansun (Guangxi SS) and Guangxi Suancai (Guangxi SC) are two kinds of traditionally fermented vegetables consumed as cooking ingredients in Guangxi Province, China, for thousands of years. However, little is known about their microbial communities as well as the differences between them. Thus, this study was aimed to investigate and compare the physicochemical indexes as well as the bacterial and fungal profiles of Guangxi SS and Guangxi SC. Results showed that the titratable acidity, lactic acid and acetic acid content in SS were significantly higher than those in SC, while the salinity of SS was significantly lower than that in SC, and the nitrite contents in all samples were are far lower than the limit of nitrite contents in fermented vegetables. Firmicutes, Proteobacteria, Ascomycota and Basidiomycota were the main phyla observed in both SS and SC samples. Lactobacillus, Serratia, Stenotrophomonas and Lactococcus were the major bacterial genera in both SS and SC samples, the predominant fungal genera in SS group were Kazachstania, Debaryomyces and Pichia, while the major genera in SC group were Kazachstania, Debaryomyces and Nakaseomyces. At the species level, Lactobacillus acetotolerans, Pichia kudriavzevii, Debaryomyces hansenii, Pichia norvegensis, Kazachstania exigua and Kazachstania humilis were the major species observed in SS, while L. delbrueckii, L. fermentum, L. aviarius, and Pichia kudriavzevii and Debaryomyces hansenii were the predominant species in SC. Salinity was found to be more strongly correlated to the bacterial and fungal communities of both SS and SC than other physicochemical factors (pH, the titratable acidity, lactic acid and acetic acid content). This study provided detailed insight into the microbial communities of Guangxi SS and Guangxi SC, and the findings may help understand the microbial structures of Chinese traditional fermented vegetables.
Section Flavi encompasses both harmful and beneficial Aspergillus species, such as Aspergillus oryzae, used in food fermentation and enzyme production, and Aspergillus flavus, food spoiler and ...mycotoxin producer. Here, we sequence 19 genomes spanning section Flavi and compare 31 fungal genomes including 23 Flavi species. We reassess their phylogenetic relationships and show that the closest relative of A. oryzae is not A. flavus, but A. minisclerotigenes or A. aflatoxiformans and identify high genome diversity, especially in sub-telomeric regions. We predict abundant CAZymes (598 per species) and prolific secondary metabolite gene clusters (73 per species) in section Flavi. However, the observed phenotypes (growth characteristics, polysaccharide degradation) do not necessarily correlate with inferences made from the predicted CAZyme content. Our work, including genomic analyses, phenotypic assays, and identification of secondary metabolites, highlights the genetic and metabolic diversity within section Flavi.
The popularity of fermented foods and beverages is due to their enhanced shelf-life, safety, functionality, sensory, and nutritional properties. The latter includes the presence of bioactive ...molecules, vitamins, and other constituents with increased availability due to the process of fermentation. Many fermented foods also contain live microorganisms that may improve gastrointestinal health and provide other health benefits, including lowering the risk of type two diabetes and cardiovascular diseases. The number of organisms in fermented foods can vary significantly, depending on how products were manufactured and processed, as well as conditions and duration of storage. In this review, we surveyed published studies in which lactic acid and other relevant bacteria were enumerated from the most commonly consumed fermented foods, including cultured dairy products, cheese, fermented sausage, fermented vegetables, soy-fermented foods, and fermented cereal products. Most of the reported data were based on retail food samples, rather than experimentally produced products made on a laboratory scale. Results indicated that many of these fermented foods contained 10
lactic acid bacteria per mL or gram, although there was considerable variation based on geographical region and sampling time. In general, cultured dairy products consistently contained higher levels, up to 10
/mL or g. Although few specific recommendations and claim legislations for what constitutes a relevant dose exist, the findings from this survey revealed that many fermented foods are a good source of live lactic acid bacteria, including species that reportedly provide human health benefits.
Consuming fermented foods has been reported to result in improvements in a range of health parameters. These positive effects can be exerted by a combination of the live microorganisms that the ...fermented foods contain, as well as the bioactive components released into the foods as by-products of the fermentation process. In many instances, and particularly in dairy fermented foods, the microorganisms involved in the fermentation process belong to the lactic acid group of bacteria (LAB). An alternative approach to making some of the health benefits that have been attributed to fermented foods available is through the production of 'fermentates'. The term 'fermentate' generally relates to a powdered preparation, derived from a fermented product and which can contain the fermenting microorganisms, components of these microorganisms, culture supernatants, fermented substrates, and a range of metabolites and bioactive components with potential health benefits. Here, we provide a brief overview of a selection of in vitro and in vivo studies and patents exclusively reporting the health benefits of LAB 'fermentates'. Typically, in such studies, the potential health benefits have been attributed to the bioactive metabolites present in the crude fermentates and/or culture supernatants rather than the direct effects of the LAB strain(s) involved.
Miso is a well‐known traditional Japanese fermented food, with a characteristic savory flavor and aroma, known predominately as the seasoning in miso soup. Miso production involves a two‐stage ...fermentation, where first a mold, such as Aspergillus oryzae, is inoculated onto a substrate to make koji. A subsequent fermentation, this time by bacteria and yeast, occurs when the koji is added to a salt and soybean mash, with the miso left to ferment for up to 2 years. The microbial community of miso is considered essential to the development of the unique taste, texture, and nutritional profile of miso. Despite the importance of microorganisms in the production of miso, very little research has been undertaken to characterize and describe the microbial process. In this review, we provide an overview of the two‐stage fermentation process, describe what is currently known about the microbial communities involved and consider any potential health benefits associated with the consumption of miso, along with food safety concerns. As the popularity of miso continues to expand globally and is produced under new environmental conditions, understanding the microbiological processes involved will assist to ensure that global production of miso is safe as well as delicious.
Bioactivity of soy-based fermented foods: A review Cao, Zhen-Hui; Green-Johnson, Julia M.; Buckley, Nicole D. ...
Biotechnology advances,
January-February 2019, 2019 Jan - Feb, 2019-01-00, 20190101, Volume:
37, Issue:
1
Journal Article
Peer reviewed
For centuries, fermented soy foods have been dietary staples in Asia and, now, in response to consumer demand, they are available throughout the world. Fermentation bestows unique flavors, boosts ...nutritional values and increases or adds new functional properties. In this review, we describe the functional properties and underlying action mechanisms of soy-based fermented foods such as Natto, fermented soy milk, Tempeh and soy sauce. When possible, the contribution of specific bioactive components is highlighted. While numerous studies with in vitro and animal models have hinted at the functionality of fermented soy foods, ascribing health benefits requires well-designed, often complex human studies with analysis of diet, lifestyle, family and medical history combined with long-term follow-ups for each subject. In addition, the contribution of the microbiome to the bioactivities of fermented soy foods, possibly mediated through direct action or bioactive metabolites, needs to be studied. Potential synergy or other interactions among the microorganisms carrying out the fermentation and the host's microbial community may also contribute to food functionality, but the details still require elucidation. Finally, safety evaluation of fermented soy foods has been limited, but is essential in order to provide guidelines for consumption and confirm lack of toxicity.
Increased consumption of yogurt, kefir, and other fermented foods has been driven, in part, by the health benefits these products may confer. Epidemiological studies have shown that the consumption ...of fermented foods is associated with reduced risks of type 2 diabetes, metabolic syndrome, and heart disease, along with improved weight management. The microorganisms present in these foods are suggested to contribute to these health benefits. Among these are the yogurt starter culture organisms Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgaricus as well as Bifidobacterium and Lactobacillus strains that are added for their probiotic properties. In contrast, for other fermented foods, such as sauerkraut, kimchi, and miso, fermentation is initiated by autochthonous microbes present in the raw material. In both cases, for these fermentation-associated microbes to influence the gut microbiome and contribute to host health, they must overcome, at least transiently, colonization resistance and other host defense factors. Culture and culture-independent methods have now clearly established that many of these microbes present in fermented dairy and nondairy foods do reach the gastrointestinal tract. Several studies have shown that consumption of yogurt and other fermented foods may improve intestinal and extraintestinal health and might be useful in improving lactose malabsorption, treating infectious diarrhea, reducing the duration and incidence of respiratory infections, and enhancing immune and anti-inflammatory responses.
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•Fermented foods are rich in microorganisms promoting health benefits.•Suitable preservation strategies to avoid probiotic damage are strongly required.•Protective agents promote the ...probiotic resistance during dehydration and storage.•Encapsulation enhances probiotic resistance during storage and GIT conditions.•Prebiotics are particularly useful because they are inert towards GIT conditions.
The development of functional foods containing probiotics has experienced a great boom in the last years, reflected by the increasing number of novel products available at the market, as well as by the well-documented extensive research, going beyond the traditional fermented dairy foods. However, to safe arrive to their target, the gut, microorganisms contained in food products have to overcome different barriers, both technological and physiological. Food processing might cause different types of damages on beneficial bacteria, which finally lead to a decrease of viability. In addition, once ingested, and before arriving to the gut, microorganisms are exposed to other food constituents, low pH and digestive juices, all of them constituting detrimental environments that can decrease their viability. For this reason, this review offers an updated state of the art on the microorganisms' response to the factors affecting their survival during drying techniques, storage and rehydration. Current strategies to overcome detrimental processing effects on bacterial viability are also reviewed, as well as the effect of food matrices on bacterial protection during food manufacturing and storage. The effect of probiotic microorganisms on the gut, and in particular on the intestinal microbiota is an issue of increasing interest in the last decades, and thus, special emphasis was put it on.
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