Search results for "lactic acid"
showing 10 items of 660 documents
Impact of oxidoreduction potential and of gas bubbling on rheological properties of non-fat yoghurt
2010
International audience; The aim of this work was to study the effect of different gaseous conditions on the physico-chemical properties of yoghurt. Four conditions of oxidoreduction potential (Eh7), +433 mV (milk gassed with air), +405 mV (ungassed milk), +283 mV (milk gassed with N2) and −349 mV (milk gassed with N2–H2) were applied to milk. The rheological properties and microstructure of these yoghurts were determined by measuring apparent viscosity, whey separation (WS) and using confocal laser scanning microscopy. Exopolysaccharide (EPS) production by lactic acid bacteria (LAB) was also studied, and production was increased for extreme Eh7 values: the highest values were obtained for a…
Inhibition of lactate export by quercetin acidifies rat glial cells in vitro
1997
The relationship between glial lactate release and glial intracellular pH (pH i) regulation is studied using C6 glioma cells and rat astrocytes in vitro, and the lactate transport inhibitors quercetin and a-cyano-4-hydroxycinnamate (CHC). pHi is measured using 2′,7′bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). The results show that lactate release is mediated partly by a specific lactate transport system inhibitable by quercetin (50 mM), but not by CHC (5 mM). Inhibition by quercetin results in a significant 3‐4-fold increase of intracellular lactate and a decrease of intracellular pH to 6.9. A participation of quercetin-inhibitable lactate transport in glial pHi-regulation is suggested…
An overview of the microbiological characteristics of the wooden shelves used in cheese ripening
2022
Cheese ripening is a complex phenomenon affected by several factors. Among these, the influence of the wooden shelves used for aging traditional cheeses is underrated. The surfaces of the wooden boards are in contact with cheese rind for the entire ripening period and develop a microbial community. The aims of this review article is to provide an overview on the microbiological approaches applied to study the biofilms associated to the wooden tools used for dairy productions and to summarize the studies specifically performed on the wooden shelves used to ripen traditional cheeses. A critical discussion is focused on the hygienic aspects and the safety of these systems applied in cheese pro…
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…
Malic Enzyme and Malolactic Enzyme Pathways Are Functionally Linked but Independently Regulated in Lactobacillus casei BL23
2013
ABSTRACT Lactobacillus casei is the only lactic acid bacterium in which two pathways for l -malate degradation have been described: the malolactic enzyme (MLE) and the malic enzyme (ME) pathways. Whereas the ME pathway enables L. casei to grow on l -malate, MLE does not support growth. The mle gene cluster consists of three genes encoding MLE ( mleS ), the putative l -malate transporter MleT, and the putative regulator MleR. The mae gene cluster consists of four genes encoding ME ( maeE ), the putative transporter MaeP, and the two-component system MaeKR. Since both pathways compete for the same substrate, we sought to determine whether they are coordinately regulated and their role in l -m…
The influence of the wooden equipment employed for cheese manufacture on the characteristics of a traditional stretched cheese during ripening
2015
Abstract The influence of the wooden equipment used for the traditional cheese manufacturing from raw milk was evaluated on the variations of chemico-physical characteristics and microbial populations during the ripening of Caciocavallo Palermitano cheese. Milk from two farms (A, extensive; B, intensive) was processed in traditional and standard conditions. Chemical and physical traits of cheeses were affected by the farming system and the cheese making technology, and changed during ripening. Content in NaCl and N soluble was lower, and paste consistency higher in cheese from the extensive farm and traditional technology, whereas ripening increased the N soluble and the paste yellow and co…
Production of functional probiotic, prebiotic, and synbiotic ice creams
2010
In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria, after frozen storage that met the minimum required to achieve probiotic effects. Moreover; most of the ice creams show…
Preliminary characterization of wild lactic acid bacteria and their abilities to produce flavour compounds in ripened model cheese system.
2007
Aims: The aim of this work was to preliminary characterize wild lactic acid bacteria (LAB), previously isolated during artisanal Pecorino Siciliano (PS) cheese-making for technological and flavour formation abilities in a model cheese system. Methods and Results: Twelve LAB were studied for the ability to grow at 10 and 45°C, to coagulate and acidify both reconstituted skim milk and ewe's milk. Moreover, the capacity of the strains to generate aroma compounds was evaluated in a model cheese system at 30- and 60-day ripening. Flavour compounds were screened by sensory analysis and throughout gas chromatography (GC)–mass spectrometry (MS). Most of the strains were able to grow both at 10 an…
Effect of different mineral salt mixtures and dough extraction procedure on the physical, chemical and microbiological composition of Şalgam: A black…
2021
NaCl is utilized in Salgam at 1-2% (w/w). The aim of this study was to reduce the NaCl content by addition of different concentrations of KCl and CaCl2 during production and evaluate their effects on quality. An innovation in production process was also employed, specifically dough extraction and use of the resulting liquid as a starter inoculum. Lactic acid bacteria (LAB) species (13) were identified using a combined approach of (RAPD)-PCR and 16S rRNA gene sequencing. Lactobacillus paracasei and Lactobacillus plantarum were dominant, but Leuconostoc mesenteroides subsp. jonggajibkimchii, Lactococcus lactis subsp. cremoris, Lactobacillus coryniformis subsp. coryniformis, Lactobacillus para…
A factory-scale application of secondary adjunct cultures selected from lactin acid becteria during Puzzone di Moena cheese ripening
2008
The lactic acid populations of 2 seasonal Puzzone di Moena cheeses made from winter and summer raw cow's milk were characterized at different ripening times. Lactic acid bacteria (LAB) were isolated on selective media and subjected to genetic typing and identification. The species most frequently found during ripening were Lactobacillus paracasei ssp. paracasei, Lactobacillus plantarum, and Pediococcus pentosaceus. The different strains recognized by random amplification of polymorphic DNA-PCR were characterized for their acidifying and proteolytic activities to select nonstarter LAB to be used as secondary adjunct cultures (SAC). For each of the 3 above species, a strain showing weak acidi…