Changes in Numbers and Kinds of Lactic Acid Bacteria During Ripening of Kefalotyri Cheese

Litopoulou-Tzanetaki, E.

doi:10.1111/j.1365-2621.1990.tb06029.x

Cited by 67 publications

(35 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They occur and grow in a wide variety of artisanal cheeses produced in southern Europe (Portugal, Spain, Italy and Greece) from raw or pasteurised goat's, ewe's, water-buffalo's or bovine milk. High levels of contaminating enterococci usually result from poor hygienic practices during cheese manufacture [48,51,66] and lead to deterioration of sensory properties in some cheeses but they play a major role in ripening and aroma development in other cheese varieties [11,13,48,54,56,67,68]. Moreover, for some Enterococcus species there is no evidence at present for a role in human disease [15].…”

Section: Introductionmentioning

confidence: 99%

“…The dominance or persistence of enterococci in some cheeses during ripening can be attributed to their wide range of growth temperatures, their high tolerance to heat, salt and acid [31,48,49,56,72] and their production of proteolytic enzymes involved in casein degradation [68,72]. Also, salt concentration increases during cheese ripening.…”

Section: Introductionmentioning

confidence: 99%

“…This is an important selection factor for growth of salt-tolerant enterococci and Lb. plantarum during the late stages of cheese ripening [31,48,56]. The beneficial effect of enterococci in cheesemaking has been attributed to hydrolysis of milk fat by esterases [69].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Proteolytic, lipolytic and autolytic activities of enterococci strains isolated from Egyptian dairy products

El-Din¹,

El‐Soda

Ezzat

2002

Lait

View full text Add to dashboard Cite

-Enterococci were isolated from Egyptian Domiatti and Mish cheeses made from raw milk. The proteolytic, lipolytic and autolytic activities of the isolated strains were studied to select the most appropriate cultures to be used for the enhancement of the organoleptic properties of cheese. The intracellular peptide hydrolase activities of enterococci strains were determined using various synthetic aminopeptidase and dipeptidyl-aminopeptidase substrates. 4-nitrophenyl and 2-nitrophenyl derivatives of fatty acids were used to measure the esterolytic activity of the different strains while emulsions of various triglycerides and butter fat were used to evaluate their lipolytic activities.The autolytic properties of the cultures were also considered. Three strains of Enterococcus faecium were freeze-shocked and evaluated as adjunct cultures in a cheese slurry system. All the strains exhibited an aminopeptidase activity hydrolysing leucyl 4-nitroanilide faster than the arginyl, alanyl, prolyl or glycyl derivatives. An active dipeptidyl-aminopeptidase activity was also detected. The Enterococcus faecium strains showed an active esterase system. The 4-nitrophenyl derivatives of the fatty acids were hydrolysed faster than the 2-nitrophenyl. The lipase substrates were hydrolysed according to the following order: tributyrin > tricaproin > tricaprylin > butterfat. The autolytic properties varied according to the strains tested. Cheese slurries ripened with adjunct Enterococcus faecium exhibited considerably higher levels of water-soluble nitrogen (WSN) and total free amino acids (FAA) when compared to the control after incubation for 5 d at 32 o C. With this finding, a high variability of some technologically relevant properties was found and could be the basis for the selection of specific cultures to be used as adjunct cultures in the production of traditional cheeses. Enterococcus / aminopeptidase / esterase / autolyse / levain atténué

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Proteolytic, lipolytic and autolytic activities of enterococci strains isolated from Egyptian dairy products

El-Din¹,

El‐Soda

Ezzat

2002

Lait

View full text Add to dashboard Cite

show abstract

“…It should be noted that significant numbers of enterococci are present in many dairy products, especially those originating from the Mediterranean area. In many cheeses, such as Comté, Cebreiro, Mozzarella, Kefalotyri, Serra, Manchego, Feta, and Teleme, enterococci comprise a major part of the fresh cheese microflora, and in some cases they are the predominant microorganisms in the fully ripened product (3,4,8,27,28,30,36). It has been concluded in many reports that enterococci may have an important role in cheese production, contributing to the ripening and quality of the mature products (5,30,34,35).…”

mentioning

confidence: 99%

Citrate Metabolism by Enterococcus faecalis FAIR-E 229

Sarantinopoulos

Kalantzopoulos

Tsakalidou

2001

Appl Environ Microbiol

View full text Add to dashboard Cite

Citrate metabolism by Enterococcus faecalis FAIR-E 229 was studied in various growth media containing citrate either in the presence of glucose or lactose or as the sole carbon source. In skim milk (130 mM lactose, 8 mM citrate), cometabolism of citrate and lactose was observed from the first stages of the growth phase. Lactose was stoichiometrically converted into lactate, while citrate was converted into acetate, formate, and ethanol. When de Man-Rogosa-Sharpe (MRS) broth containing lactose (28 mM) instead of glucose was used, E. faecalis FAIR-E 229 catabolized only the carbohydrate. Lactate was the major end product, and small amounts of ethanol were also detected. Increasing concentrations of citrate (10, 40, 70, and 100 mM) added to MRS broth enhanced both the maximum growth rate of E. faecalis FAIR-E 229 and glucose catabolism, although citrate itself was not catabolized. Glucose was converted stoichiometrically into lactate, while small amounts of ethanol were produced as well. Finally, when increasing initial concentrations of citrate (10, 40, 70, and 100 mM) were used as the sole carbon sources in MRS broth without glucose, the main end products were acetate and formate. Small amounts of lactate, ethanol, and acetoin were also detected. This work strongly supports the suggestion that enterococcal strains have the metabolic potential to metabolize citrate and therefore to actively contribute to the flavor development of fermented dairy products.The industrial importance of lactic acid bacteria is mainly based on the ability of these organisms to rapidly ferment carbohydrates and to convert them into lactic acid and, to a lesser degree, into other flavor compounds. Lactic acid provides protection against spoilage by nonacidophilic organisms. On the other hand, many lactic acid bacteria are also able to ferment a number of noncarbohydrates, including citrate. Citrate metabolism plays an important role in many food fermentations involving lactic acid bacteria, since it occurs in many natural substrates, such as milk, vegetables, and fruits (21). The behavior of lactic acid bacteria may differ from one species to another, and not all lactic acid bacteria are able to metabolize citrate (24).The ability to metabolize citrate is invariably linked to endogenous plasmids that contain the gene encoding the transporter which is responsible for citrate uptake from the medium (2). Since citrate is a highly oxidized substrate, no reducing equivalents, such as NADH, are produced during its degradation, which results in the formation of metabolic end products other than lactic acid. Some of these end products, such as diacetyl, acetaldehyde, and acetoin, have very distinct aroma properties and significantly influence the quality of fermented foods (20). For instance, diacetyl determines the aromatic properties of fresh cheese, fermented milk, cream, and butter (12) but is considered the most important off-flavor compound in the brewing process and in the wine industry (22). The breakdown of citrate also results in the p...

show abstract

“…Enterococci can survive the ripening period due to their tolerance to salt and acidic conditions and they can, also, survive in traditional fermented cheeses, such as kefalotyri and Feta (Litopoulou-Tzanetaki 1990, Litopoulou-Tzanetaki andTzanetakis 1991). In recent years, strains of E. faecium and E. faecalis were found to be resistant to vancomycin and they have been recognized as major nosocomial pathogens that are responsible for a variety of infections.…”

Section: (Cordano and Rocourt 2001)mentioning

confidence: 99%

Survival of pathogens in "Graviera Kritis" cheese made with raw and pasteurized milk

Samouris

Ζdragas

Vafeas

et al. 2017

J Hellenic Vet Med Soc

View full text Add to dashboard Cite

A field trial was carried out to investigate the hygienic status of Graviera 'Kritis' cheese made with raw and pasteurized milk. Graviera was manufactured in a small plant in Crete under traditional manufacturing conditions. Forty-two samples were examined during the manufacturing process for Colifoms, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., Escherìchia coli 0157:H7 and VRE (Vancomycin Resistant Enterococci). All samples were negative for Salmonella spp., E. coli 0157:H7 and VRE. Populations of Colifoms and E. coli before cooking of the curd were 3 3.5 log10MPN/g higher in cheese made with raw milk in comparison to that made with pasteurized milk and populations of both bacteria decreased sharply during the aging period in both types of cheese. L. monocytogenes type 4b was isolated from the cheeses of two trials until after the salting period and remained under the detection limit of 100 cfu/g . At the end of the ripening period, all the examined bacteria were declined or eliminated to safe level.

show abstract

Changes in Numbers and Kinds of Lactic Acid Bacteria During Ripening of Kefalotyri Cheese

Cited by 67 publications

References 13 publications

Proteolytic, lipolytic and autolytic activities of enterococci strains isolated from Egyptian dairy products

Proteolytic, lipolytic and autolytic activities of enterococci strains isolated from Egyptian dairy products

Citrate Metabolism by Enterococcus faecalis FAIR-E 229

Survival of pathogens in "Graviera Kritis" cheese made with raw and pasteurized milk

Contact Info

Product

Resources

About