Lactic acid bacteria (LAB) are considered as the main biogenic amine (BA) producers in fermented foods. These compounds derive from amino acid decarboxylation through microbial activities and can ...cause toxic effects on humans, with symptoms (headache, heart palpitations, vomiting, diarrhea) depending also on individual sensitivity. Many studies have focused on the aminobiogenic potential of LAB associated with fermented foods, taking into consideration the conditions affecting BA accumulation and enzymes/genes involved in the biosynthetic mechanisms. This review describes in detail the different LAB (used as starter cultures to improve technological and sensorial properties, as well as those naturally occurring during ripening or in spontaneous fermentations) able to produce BAs in model or in real systems. The groups considered were enterococci, lactobacilli, streptococci, lactococci, pediococci, oenococci and, as minor producers, LAB belonging to
and
genus. A deeper knowledge of this issue is important because decarboxylase activities are often related to strains rather than to species or genera. Moreover, this information can help to improve the selection of strains for further applications as starter or bioprotective cultures, in order to obtain high quality foods with reduced BA content.
For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study ...assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.
Traditional Chinese fermented foods are favored by consumers due to their unique flavor, texture and nutritional values. A large number of microorganisms participate in the process of fermentation, ...especially lactic acid bacteria (LAB), which are present in almost all fermented foods and contribute to flavor development. The formation process of flavor is complex and involves the biochemical conversion of various food components. It is very important to fully understand the conversion process to direct the flavor formation in foods. A comprehensive link between the LAB community and the flavor formation in traditional Chinese fermented foods is reviewed. The main mechanisms involved in the flavor formation dominated by LAB are carbohydrate metabolism, proteolysis and amino acid catabolism, and lipolysis and fatty acid metabolism. This review highlights some useful novel approaches for flavor enhancement, including the application of functional starter cultures and metabolic engineering, which may provide significant advances toward improving the flavor of fermented foods for a promising market.
Summary
Predominant antifungal lactic acid bacteria (LAB) isolated from fermented sprouted mung bean (FSM) was used as protective starter culture in controlled FSM to produce a clean‐label fortified ...wheat bread. Sequencing results of the PCR products led to the identification of Pediococcus pentosaceus as the selected LAB isolate. The rate of surface growth of Aspergillus niger on FSM‐added bread was significantly (P < 0.05) lower than the wheat bread containing mung bean, fermented mung bean and sprouted mung bean alone. The quantity of almost all of the amino acids (aspartic acid, histidine, serine, arginine, threonine, tyrosine, valine, phenylalanine and tryptophane) in the FSM‐added wheat bread was also higher than the control, according to the HPLC analysis. Furthermore, bread containing FSM had the highest mould‐free shelf‐life (4 days) and porosity (21.61%). Meanwhile, there was no significant (P > 0.05) difference in terms of crumb hardness, specific volume and overall acceptability among the produced samples.
Clean‐label fortified wheat bread containing controlled fermented sprouted mung bean.
We report the first polyphasic characterization of native Saccharomyces cerevisiae in order to select candidate strains for the design of starter cultures tailored for Apulian sparkling wines ...obtained from local grape variety. In addition, it is the first survey in our region that propose the selection of autochthonous starter cultures for sparkling wine i) including a preliminary tailored genotypic and technological screening, and ii) monitoring analytical contribution during secondary fermentation in terms of volatile compounds (VOCs). Furthermore, we exploit the potential contribute of autochthonous cultures throughout the productive chain, including the possible improvement of base wine. One representative strain from each cluster was characterized i) for tolerance to abiotic and biotic stressors peculiar of sparkling wine fermentation, ii) for the performances in base wine production, and iii) for the aptitudes to promote in-bottle secondary fermentation in white and rosé sparkling wines, both obtained from Apulian grape varieties. Genetic characterization led to group 164 S. cerevisiae in 16 genetic clusters based on interdelta profiles. Stress tolerance assays shown a certain correlation with fermentative attitude. Our evidences demonstrated a different fermentative behavior and release of VOCs of the different strains in association with primary and secondary fermentations and as function of wine and rosé sparkling wine. Furthermore, performances in white/rosé sparkling wines have been found to be strain-dependent characters. Overall, we propose different strains as biotechnological resources suitable to improve the quality of regional sparkling wines and to provide a driver of innovation/segmentation in the market.
•We report a complete polyphasic characterization of native yeast for sparkling wine.•Characterization of strains includes VOCs determination.•The yeasts have diverse performances in base wine, white and rosé sparkling wines.•The relevance of pre-stress conditions in selecting candidate strains is discussed.•Candidate starter cultures for Apulian sparkling wines were selected.
Summary
In this study, the effect of Lactiplantibacillus (L.) plantarum XL23 (Lp) and Saccharomyces (S.) cerevisiae RC212 (Sc) on flavour formation in fermented fish sauce production was ...investigated. The levels of, and relationship between, non‐volatile and volatile compounds responsible for taste and aroma were determined in fish sauce samples. Regarding non‐volatiles, the results showed that free amino acids and organic acids were significantly higher in Lp and Lp + Sc compared to traditional fish sauce. In fatty acids, there was an irregular distribution between the groups. In terms of volatile compounds, L. plantarum supported the presence of acidic compounds (1413.31 ng mL−1), while S. cerevisiae supported the presence of alcoholic compounds at high levels (3891.56 ng mL−1). Significant correlations between components proved the accuracy of analytical and sensory analyses and demonstrated the reliability of multi‐replicate statistical interactions. The results indicated that inoculation with starter cultures changed the taste and aroma in favour of the strains.
Lactiplantibacillus plantarum and Saccharomyces cerevisiae altered the taste and aroma profiles of fish sauces. A total of seventy‐eight volatile compounds were identified in fish sauces. Traditional fermented fish sauce exhibited the highest diversity in volatile compounds. Allochthonous fermentation resulted in higher concentrations of volatiles. Strong correlations between compounds and flavours were also perceived by panellists.
Sourdough production is an ancient method to ferment flour from cereals for the manufacturing of baked goods. This review deals with the state-of-the-art of current fermentation strategies for ...sourdough production and the microbial ecology of mature sourdoughs, with a particular focus on the use of non-flour ingredients. Flour fermentation processes for sourdough production are typically carried out by heterogeneous communities of lactic acid bacteria and yeasts. Acetic acid bacteria may also occur, although their presence and role in sourdough production can be criticized. Based on the inoculum used, sourdough productions can be distinguished in fermentation processes using backslopping procedures, originating from a spontaneously fermented flour-water mixture (Type 1), starter culture-initiated fermentation processes (Type 2), and starter culture-initiated fermentation processes that are followed by backslopping (Type 3). In traditional recipes for the initiation and/or propagation of Type 1 sourdough productions, non-flour ingredients are often added to the flour-water mixture. These ingredients may be the source of an additional microbial inoculum and/or serve as (co-)substrates for fermentation. An example of the former is the addition of yoghurt; an example of the latter is the use of fruit juices. The survival of microorganisms transferred from the ingredients to the fermenting flour-water mixture depends on the competitiveness toward particular strains of the microbial species present under the harsh conditions of the sourdough ecosystem. Their survival and growth is also determined by the presence of the appropriate substrates, whether or not carried over by the ingredients added.
Pollution due to textile dye effluent mishandling is hazardous to ecosystems and to the living beings inhabiting them. This can cause retarded photosynthesis, disrupted fish day/night cycles, ...unbalanced bacterial populations, and decreased oxygen concentration in contaminated water, leading to low habitability. In this study, we aimed to isolate and characterize the microorganisms found in Indonesian cassava-based fermented food tapai starter cultures as a source of potential microbes for the biological remediation of textile dye pollutants. Microorganisms in the tapai starter culture were screened for their decolorization activity via spread-culture inoculation on a solid growth medium supplemented with textile dyes. Isolated microorganisms were selected based on their ability to secrete textile dye-decolorizing extracellular enzymes via increased light penetration after incubation of the cell-free supernatant (CFS) containing extracellular enzymes in textile dye solutions. Isolate JSP1 was the only bacterium capable of producing malachite green (MG)-decolorizing extracellular enzymes, which enabled it to survive and decolorize MG up to 375 ppm. Moreover, isolate JSP1 CFS was able to optimally decolorize 75% of MG at 100 ppm, but its activity was diminished at concentrations > 350 ppm. Colony and cellular morphology, biochemistry, and 16S rRNA tests revealed that the isolate was of
Ralstonia mannitolilytica
. Therefore,
R. mannitolilytica
isolate JSP1 may be a potential bioremediation agent for MG.
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