Search results for "fermentation"
showing 10 items of 746 documents
Traditional fermented sausage ‘Nem chua’ as a source of yeast biocatalysts efficient for the production of the aroma compound γ-decalactone
2013
International audience; The yeast ecosystem of Nem chua, a Vietnamese traditional fermented sausage naturally rich in medium‐chain‐length lipid‐derived flavouring compounds, was investigated to select biocatalysts able to produce the C10‐fatty acid‐derived aroma compound γ‐decalactone. The total number of yeast was about 5 × 104 to 4 × 105 CFU g−1, and eighty four different species were identified from morphological, physiological and 26S rDNA characteristics, with Candida sake and Candida haemulonii being found in all samples. Six strains able to produce γ‐decalactone from castor oil were selected, of which three Yarrowia lipolytica strains were able to produce between 1 and 2 g L−1 in our…
Industrial application of selected lactic acid bacteria isolated from local semolinas for typical sourdough bread production
2016
Abstract Four obligate heterofermentative lactic acid bacteria (LAB) strains (Weissella cibaria PON10030 and PON10032 and Leuconostoc citreum PON 10079 and PON10080) were tested as single strain starters, mono-species dual strain starters, and multiple strain starter for the preparation and propagation of sourdoughs for the production of a typical bread at industrial level. The kinetics of pH and TTA during the daily sourdough refreshments indicated a correct acidification process for all trials. The concentration of lactic and acetic acid increased consistently during fermentation. The resulting molar ratios between these two organic acids in the experimental trials were lower than those o…
Regulatory O 2 tensions for the synthesis of fermentation products in Escherichia coli and relation to aerobic respiration
1997
In an oxystat, the synthesis of the fermentation products formate, acetate, ethanol, lactate, and succinate of Escherichia coli was studied as a function of the O2 tension (pO2) in the medium. The pO2 values that gave rise to half-maximal synthesis of the products (pO0. 5) were 0.2-0.4 mbar for ethanol, acetate, and succinate, and 1 mbar for formate. The pO0.5 for the expression of the adhE gene encoding alcohol dehydrogenase was approximately 0.8 mbar. Thus, the pO2 for the onset of fermentation was distinctly lower than that for anaerobic respiration (pO0.5/= 5 mbar), which was determined earlier. An essential role for quinol oxidase bd in microaerobic growth was demonstrated. A mutant de…
Polyphenols in kombucha: Metabolomic analysis of biotransformations during fermentation
2022
Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. This beverage is increasingly produced at industrial scale, but its quality standards remain to be defined. Metabolomics analysis was carried out using FT-ICR-MS (Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry) to understand the chemical transformations induced by the production phases and the type of tea on the non-volatile compounds of kombucha.
Polyphenols in kombucha: impact of infusion time on extraction and investigation of their behavior during "fermentation"
2022
Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. Polyphenols are expected to be responsible of several health benefits attributed to kombucha consumption, among other metabolites. Evidence point at an enhancement of tea polyphenol bioactivity during kombucha elaboration. This study investigated the impact of tea infusion time and of kombucha "fermentation", on the tea polyphenols and the color. Most of the present experiments have been carried out during a 3 rd year Bachelor training by Shane Fennell from Carlow Institute of Technology (Ireland).
Current Evidence on Physiological Activity and Expected Health Effects of Kombucha Fermented Beverage
2013
Consumption of kombucha fermented tea (KT) has always been associated with different health benefits. Many personal experiences and testimonials of KT drinkers are available throughout the world on the ability of KT to protect against a vast number of metabolic and infectious diseases, but very little scientific evidence is available that validates the beneficial effects of KT. The aim of this review is to give an overview of the recent studies in search of experimental confirmation of the numerous KT health-promoting aspects cited previously. Analysis of the literature data is carried out in correspondence to the recent concepts of health protection's requirements. Attention is given to th…
Microbiological and technological parameters impacting the chemical composition and sensory quality of kombucha
2020
International audience; Kombucha is a beverage made from sugared tea transformed by yeasts and acetic acid bacteria. Being originally homemade, it has become an industrially produced soft drink whose quality standards are poorly defined and whose production process is still not fully controlled. Based on current knowledge in beverages, links between kombucha's chemical composition and sensorial compounds are drawn. Macromolecules create turbidity, whereas uncharacterized tea pigments derivatives participate in the color. Residual sugars bring sweetness and organic acids produced by acetic acid bacteria form its characteristic sour taste. Acetic acid is also part of its aroma profile, althou…
Origines des levures Saccharomyces et non-Saccharomyces présentes dans le moût : Vignoble ou cuverie ?
2017
International audience; Les levures de l’espèce Saccharomyces cerevisiae ont longtemps été considérées comme les seules responsables du processus de fermentation. On sait aujourd’hui que différentes espèces de levures Saccharomyces et non-Saccharomyces (NS) sont présentes dans les moûts et qu’un certain nombre d’entre elles participe à la fermentation alcoolique (FA). Bien qu’il soit aujourd’hui largement admis que les principales sources de levures dans le moût de raisin sont les baies de raisin et le matériel de vinification (Fleet et Heard, 1993 ; Mortimer et Polsinelli, 1999) (figure 1), la part apportée par chacune de ces deux sources est encore mal définie. De plus, d’autres sources p…
Comprehension and food analysis of a fermented mixture of animal proteins and vegetable proteins : influence on the physico-chemistry and the accepta…
2017
Many problems have been identified following the attempts to incorporate vegetal proteins in our food. In particular, off-flavor, taste or texture have been highlighted as real barriers to the acceptability of plant products by consumers. The consumer himself is also an important determinant regarding the term "acceptability." So, in order to develop a new fermented product based on pea, two issues were studied: the product and the consumer. To understand the physico-chemical properties and the acceptability of pea protein-based fermented products, several factors have been investigated in successive stages such as culture, positive health and environmental claims, lactic acid bacteria stra…
Influence of the Fermented Feed and Vaccination and Their Interaction on Parameters of Large White/Norwegian Landrace Piglets
2020
The aim of this study was to evaluate the influence of fermented with a newly isolated lactic acid bacteria (LAB) strains combination (Lactobacillus plantarum LUHS122, Lactobacillus casei LUHS210, Lactobacillus farraginis LUHS206, Pediococcus acidilactici LUHS29, Lactobacillus plantarum LUHS135 and Lactobacillus uvarum LUHS245) feed on non-vaccinated (NV) and vaccinated with Circovac porcine circovirus type 2 vaccine (QI09AA07, CEVA-PHYLAXIA Co. Ltd. Szá