Cheese propionic acid

CH3CH2COH Swiss cheese Propionic acid Propanoic acid 141... 

Lactate. Hard rennet cheeses represent a selective habitat for propionic acid bacteria, since they contain lactate formed as the end product of lactose fermentation by lactic acid bacteria. Unlike many other bacteria, propioni-bacteria can utilize lactate efficiently, which is the reason why propioni-bacteria are so abundant in hard, ripened cheeses. Propionic acid bacteria use lactate best in the presence of yeast extract (Antila, 1954), but even higher stimulatory effect is exerted by cell-free extracts of lactic acid bacteria. Streptococcus thermophilus and Lactobacillus spp. (Hietaranta and Antila, 1953). Lactate as a carbon source supports higher growth rates of propionic acid bacteria than lactose (El-Hagarawy et al., 1954). 

There is evidence that among the fatty acids only butyric and caproic acids 42), at sub-threshold concentrations, interact to contribute to the desirable butter flavor 367). A whole set of fatty acids provide a background flavor in the case of Cheddar cheese. Propionic acid is an essential flavor component in Swiss cheese 330). The characteristic flavor of blue cheese, however, is due to the presence of aliphatic methyl-ketones 161, 308). 

Propionates. Propionic acid [79-09-4], C2H 02, and its calcium and sodium salts ate effective mold inhibitors. They ate particularly useful in yeast-leavened baked products because they do not affect the activity of yeast. In addition to being widely used in baked goods, they ate used as mold inhibitors in cheese foods and spreads (77). 

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Bacteria from the genera Lactobacillus and Streptococcus are involved in the first steps of dairy production (3). The raw materials produced by their effects usually only acquire their final properties after additional fermentation processes. For example, the characteristic taste of Swiss cheese develops during a subsequent propionic acid fermentation. In this process, bacteria from the genus Propionibacterium convert pyruvate to propionate in a complex series of reactions (2). 

S. thermophilus metabolizes lactose to l( +) lactic acid but utilizes only the glucose moiety of lactose, leaving the galactose moiety in the cheese (Tinson et al. 1982). In Swiss cheese manufacture, S. thermophilus metabolizes the lactose and L. helveticus metabolizes the galactose to d( —) and l( + ) lactic acid (Turner et al. 1983). The l( + ) lactate isomer is preferentially utilized by propionibacteria to form acetic and propionic acids, which are essential for the development of the characteristic flavor in Swiss cheese (Langsrud and Reinbold 1973). 

Fermentation of lactic acid to yield propionic acid, carbon dioxide, acetic acid, and succinic acid is important for proper eye formation and flavor development in Emmental, Gruyere, and Swiss-type cheese varieties. This fermentation is associated with Propionibacterium spp. subspecies of Propionibacterium freudenreichii are of greatest significance. These organisms can also be used for industrial production of vitamin Bi2 and propionic acid. 

Laboratory-scale experiments which used L. casei symbiotically with Propionibacterium freudenreichii in the fermentation of whey gave an average yield of 2.2 mg of vitamin per liter the maximum was 4.3 mg/liter. Production of vitamin Bi2 is not species-specific. All species of Propionibacterium, when cultivated under the same conditions, produce active substances, but in different quantities. P freudenreichii and P zeae synthesized sufficient quantities to warrant their consideration for commercial exploitation. Because propionic acid bacteria are active during Swiss cheese ripening, it was anticipated, and actually demonstrated, that production of vitamin Bi2 in Swiss cheese is influenced by the same factors that influence its production in pure culture, particularly by the cobalt content of milk (Hargrove and Leviton 1955). 

Organic acids may exhibit other sensory properties. For example, citric acid possesses sweet-and-sour sensory notes, and succinic acid has a salty-bitter taste. On the other hand, the typical taste and flavor of Emmental cheese can be ascribed to the propionic acid and a few other compounds, such as proline. In fact, taste and flavor result from the combination of different food constituents in definite proportions. Raw meat smells much like lactic acid, which arises from postmortem anaerobic glucolysis and determines the pH of meat, its final properties, and microbial stability. This same organic acid has been related to the inhibition of certain pathogenic bacteria in yogurt (3). Table 1 lists the reported threshold concentrations for various organic acids in different media (4-6). 

FA, LA, propionic acid Commercial cheeses extraction in mobile phase, centrifuged Nucleosil C18 (120 X 5 mm) 0.5% (NH4)2HP04 buffer (pH 2.24 with H2P04) 0.4% acetonitrile UV 214 nm 82... 

I Saito, H Oshima, N Kawamura, K Uno, M Yamada. Determination of sorbic, dehydroacetic, and propionic acids in cheese by liquid chromatography and gas chromatography. J Assoc Off Anal Chem 70 507-509, 1987. 

Systematic names for carboxylic acids use the -oic acid suffix, but historical names are commonly used. Formic acid was first isolated from ants, genus Formica. Acetic acid, found in vinegar, gets its name from the Latin word for sour (acetum). Propionic acid gives the tangy flavor to sharp cheeses, and butyric acid provides the pungent aroma of rancid butter. 

Separation of lactic and propionic acids. The lactose fraction in the sweet whey permeate from cheese whey ultrafiltration can be fermented to produce lactic acid. In conjunction with the fermentation step, inorganic membranes have been tested in a continuous process to separate the lactic acid. This approach improves the productivity and reduces energy consumption compared to a conventional fermentation process. In addition, it produces a cell-free product. In a conventional process, some cells, although immobilized, are often detached and released to the product Zirconia membranes with a MWCX) of 20,000 daltons were operated at 42 C and a crossflow velocity of 2-5 m/s for this purpose [Boyaval et al., 1987]. The resulting permeate flux is 12-16 L/hr-m. To... 

Propionic acid and its derivatives are used in food, perfume and plastic applications. Traditional processes for making this compound, however, have limited productivity due to the low growth rate of the propionic bacteria and the inhibitory effect of the acid on the fermentation. The cheese whey permeate can be an inexpensive source of propionic acid. Propionic acids can be produced by fermentation of sweet whey permeate in a stirred tank reactor with cells separated from the medium and recycled back to the reactor by an ultrafiltration Z1O2 membrane on a carbon support [Boyaval and Corre, 1987]. This arrangement reduces the propionic acid concentration and increases the... 

Propionic acid is generally regarded as a nontoxic and nonirritant material when used as an excipient. Up to 1% may be used in food applications (up to 0.3% in flour and cheese products). See also Sodium Propionate. 

Sodium propionate and other propionates are used in oral pharmaceutical formulations, food products, and cosmetics. The free acid, propionic acid, occurs naturally at levels up to 1 % w/w in certain cheeses. 

Some other cheese flavours (Provolone, Emmentaler and other miscellaneous cheesy flavour notes) can be obtained by fermentation of edible fats by means of microorganisms which are producing butter or propionic acid from these fats. 

Propionic acid (Figure 2.12) was first described in 1844. Propionic acid occurs in foods by natural processing. It has been found in Swiss cheese at concentrations of up to 1% and is produced by the bacterium Propionibacterium shermanii. Antimicrobial activity of propionic acid is reported to be primarily against molds and bacteria (Barbosa-Canovas et al., 2003). Commercial products containing propionic acid include... 

Swiss cheeses are distinguished from other varieties by different starter cultures used and the subsequent growth of propionibacteria with gruyere cheeses, yeasts and coryneforms. Fermentation of lactic acid and residual sugars by propionic bacteria to propionic acid is vital in flavor development, and follows initial lactic acid fermentation by the starters. The propionibacteria also apparently contain peptidases which release the sweet-tasting amino acid proline, according to some investigators(13), an important Swiss cheese tastant. 

Propionic acid (propanoic acid) CH3CH2COOH Swiss cheese Gk protos, first pkm, fat... 

Lactate serves as substrate for the production of propionic acid, acetic acid, and CO2 during the ripening of Swiss-type cheeses. 

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