Different Varieties Of Cheese Research Articles

Assessment of sodium chloride tolerance and antibiotic resistance of Citrobacter braakii EC-PS1 and Macrococcus caseolyticus Li-PT1 isolated from artisanal cheeses

Abstract The different varieties of cheese are fermented dairy products with high nutritional value, which have been part of the healthy human diet for centuries. Cheeses are characterized by complex and diverse microbiota carrying beneficial, spoilage, or foodborne pathogen bacteria. Harmful bacteria originate from the production chain. Identification and characterization of microorganisms in cheese are important nutritional, food safety, and technological issues. During this study, Citrobacter braakii EC-PS1 and Macrococcus caseolyticus Li-PT1 bacteria strains, isolated on selective mediums from two artisanal cheeses, were identified by way of 16S rDNA gene sequence analysis. Their antibiotic resistance and NaCl stress tolerance were also determined M. caseolyticus Li-PT1 showed tolerance to 6.5% and 10% NaCl. The increasing NaCl concentration above 15% contributed to the decrease of viability in bacteria. The increasing NaCl concentration to 10% contributed to the decrease of viability in C. braakii EC-PS1 bacteria. The identified bacterial species exhibited different levels of resistance to the tested antibiotics C. braakii EC-PS1 showed resistance to chloramphenicol, ampicillin, and streptomycin, whereas M. caseolyticus Li-PT1 was susceptible only to two antibiotics (erythromycin, tetracycline) out of the eight tested.

Influence of Ultra-Heat Treatment on Properties of Milk Proteins.

Milk can be considered one of the primary sources of nutrients for the mammalian neonate. Therefore, milk and milk-based products, such as infant formula, whey protein isolate, different varieties of cheese, and others are prepared to meet the nutritional requirements of the consumer. Due to its significant nutritional components and perishable nature, a variety of pathogenic microorganisms can grow and multiply quickly in milk. Therefore, various heat treatments can be employed for the improvement of the shelf life of milk. In comparison to pasteurized milk, due to excessive and severe heating, UHT milk has a more cooked flavor. During storage, changes in the physicochemical properties of milk can lead to off-flavors, undesirable browning, separation of fat, sediment formation, or gelation during the subsequent storage. Several important factors such as processing parameters, time-temperature abuse (storage condition), and packaging type also influence the quality characteristics and consumer acceptance of the milk; however, the influence of heat treatments on milk protein is inconstant. The major protein modifications that occur during UHT treatment are denaturation and aggregation of the protein, and chemical modifications of its amino acids. These UHT-induced protein alterations can change digestibility and the overall biological influence of the intake of these proteins. Therefore, this review is focused on the influence of UHT on the physicochemical and structural attributes of milk proteins during storage. There are many indications of milk proteins present in the UHT milk, and milk products are altered during processing and storage.

Dynamic price relationships and price discovery among cheese markets

The United States (U.S.) cheese sector has been steadily growing throughout the years. Since 1980, U.S. consumers have doubled their annual consumption of cheese, currently at about 37.9 lbs. per capita in 2018 excluding cottage cheese. Cheese varieties are generally classified as American type (Cheddar, Monterey and others), Italian type (Mozzarella and others), and Other type (Swiss, Muenster and others) since they serve different markets. American cheese is consumed regularly in hamburgers, sandwiches and in similar settings. Italian cheese is typically consumed in pizzas, pasta and Italian cuisine. Despite the burgeoning growth in cheese demand, there has been no study addressing the dynamic price relationship among different varieties of cheese. This study investigates the price discovery process among cheese varieties: Cheddar, Mozzarella, Swiss, Muenster, and Monterey by using a vector error correction model and standard innovation accounting. Results indicate relative price interaction among different varieties of cheese, providing empirical evidence of some decouplment or separation among American (Cheddar and Monterey), Italian (Mozzarella), and Other type (Swiss). An exemption is Muenster which despite being classified as Other type of cheese responds to American’s Cheddar.

Antifungal and antibacterial effects of newly created lactic acid bacteria associations depending on cultivation media and duration of cultivation

BackgroundThe newly created associations of lactic acid bacteria (LAB) isolated from Armenian dairy products (yoghurt, sour cream and different varieties of cheese), as well as from the gastrointestinal tract of honeybees were screened according to their antifungal and antibacterial activity.ResultsLAB strains were mixed at equal proportions (1:1) according to mathematical planning of experiments. Antifungal and antibacterial effects of different combinations (associations) were determined in different media, employing well-diffusion and total diffusion into agar methods. A number of fungal and bacterial test-organisms, including pathogenic ones, were used. Pure LAB strain cultures were used as a control. The antifungal effect of the most active strain Lactobacillus rhamnosus MDC 9661 in the associations with other LAB strains was partly decreased. At the same time, some mixed LAB cultures in DeMan, Rogosa and Sharpe (MRS) medium demonstrated significant antibacterial activity against wide spectra of test-organisms only in the case of simultaneous cultivation of LAB strains. On the other hand, in the case of different LAB strains cultivated in MRS with 24-h time break between mix formations by different strains, no inhibitory activity was revealed. But the inhibitory effect of many LAB associations against test-organisms was significantly increased in the case of separated cultivation in milk.ConclusionThe inhibitory effect of mixed LAB associations showed stronger dependence on the cultivation media and on the duration of cultivation with respect to each other. The co-cultivation of some strains, like L. rhamnosus MDC 9661, could lead to changed antagonistic activity. Consequently, the results are significant for creation and further investigation of LAB associations, as effective probiotics, and for their probable application in the production of antimicrobial preparations.

Potencial biológico y estudio in vitro de la digestión de péptidos solubles de diferentes variedades de queso

CCurrently, the concern with quality of life has raised the consumption of health food promoters, and therefore, research in search of natural compounds that exercise biological activity have intensified in the last decade. The objective was to evaluate the antioxidant activities, chelating Fe2+ and Cu2+ ions, antihypertensive proteins and water-soluble peptides of buffalo and bovine rennet cheeses, gorgonzola, mozzarella, cheddar and ricotta. The antioxidant activities were performed using the radicals ABTS+ • (2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl), Fe2+ and Cu2+ ions were used for chelating activity and the substrate FAPGG (N- [3- (2-furyl) acryloyl] -L-phenylalanine-glycyl-glycine) was used to evaluate the inhibition of angiotensin converting enzyme. The water-soluble proteins and peptides from the different varieties of cheese had the capacity to eliminate ABTS+ • and DPPH• radicals higher than 50% and 80%, respectively. The chelation of the Fe2+ and Cu2+ ions occurred between 1% and 70%, depending on the type of cheese. The ACE inhibitory potential of the aqueous extracts containing the small protein fragments is between 8% and 50% before and after the action of the enzymes of the gastrointestinal tract. Thus, the cheeses analyzed have the potential to be used as functional foods due to the biological multifunctionality presented by proteins and peptides extracted.

Public Health Risks Of Biogenic Amines From Curd Dairy Products

Biogenic amine content of cheese can be extremely variable and depends on the type of cheese, the ripening time and the manufacturing process. The amount of biogenic amines in cheese may act as a useful indicator of the hygienic quality of the product. One hundred and forty samples of different varieties of cheese represented as (Kareish, Damietta, Ras, Mish, Cheddar, Edam and Roquefort) 25 of each were collected from groceries, and supermarkets from different localities in Alexandria city for determination of Five biogenic amines including histamine, tyramine, cadaverine and putrescine and tryptamine by high performance liquid chromatography. The highest histamine mg/100 g levels were detected in the examined mish cheese followed by Ras cheese while, histamine failed to be detected in the examined Roquefort cheese. Tyramine level was detected in all examined cheese samples except Roquefort cheese and the percent of positive samples that exceeded the permissible limit of ES (2007) and FDA (2001) were 40 and 55%, respectively. All positive samples of Cheddar, Edam and Roquefort cheeses for cadaverine were within the ES (2007) permissible limit While, all positive samples of examined cheese samples were above the FDA (2001) permissible limit except Roquefort cheese. While, only one sample from of positive putrescine examined samples of Damietta, Cheddar and Edam cheese were above the permissible limit. All examined cheese samples were within the permissible limit of tryptamine level according to ES (2007) and FDA (2001) Public health hazards of biogenic amines in different cheeses and suggestion to produce high quality cheese was discussed to come in accordance with the safe permissible limit to ensure human safety.

Chemical composition and nutritional quality of short-ripened rennet cheeses produced by traditional methods

The aim of the study was to determine the variability in the chemical composition and nutritive value parameters of smoked and unsmoked short-ripened rennet cheeses and unsmoked long-ripened rennet cheeses produced by traditional methods. The raw material for the production of short-ripened cheeses was pasteurized cows’ milk obtained from a dairy, whereas the long-ripened cheeses were manufactured from raw cows’ milk obtained from the producer’s farm. All three varieties of cheese examined were produced with commercial dairy starter cultures. The material for the study was collected in winter, directly at the producers’ retail outlets in southern and eastern Poland. The basic chemical composition was determined according to the Polish Standards, whereas the amino acid profiles of proteins from the cheeses were determined by ion-exchange chromatography. The result analysis revealed significant differences between the different varieties of cheese in terms of their water content, ranging from 32.2% to 42.1%, as well as protein content, which varied from 25.6% to 31.6%. Fat levels ranged between 22.2% and 24%, whereas total ash content amounted to 5.1-5.8%. The significantly highest salt content was found in unsmoked short-ripened cheeses. In all three cheese varieties, the total exogenous amino acid content was comparable, ranging from 46.17 g to 47.36 g/100 g protein, and that of endogenous amino acids varied from 52 g to 53 g/100 g protein. The biological value of proteins was determined by calculating to the chemical score (CS), as described by Mitchell and Block, and the essential amino acid index (EAAI), as described by Oser. A comparison of the results with the standard chicken egg white proteins showed that the limiting amino acids for all varieties of cheese were methionine and cysteine. On the other hand, a comparison with the FAO/WHO-suggested pattern of amino acid requirements (1991) for all age groups over 1 year of age showed that the limiting amino acids were methionine and cysteine in smoked and unsmoked short-ripened cheeses, and treonine in long-ripened cheeses. Considering the chemical indices, such as CS and EAAI, it may be concluded that the traditional rennet cheeses produced in southern and eastern Poland have a favourable amino acid composition of proteins and a high nutritive value..

Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry.

RationaleThe rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT‐MS), proton transfer reaction mass spectrometry (PTR‐MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet‐pump‐based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis.MethodsVolatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples.ResultsThe interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter‐day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively.ConclusionsThe described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats.

Rapid determination of sodium in milk and milk products by capillary zone electrophoresis

A capillary zone electrophoresis method for the determination of Na in milk and milk products was developed and compared with an International Organization for Standardization/International Dairy Federation standard method that is based on flame atomic absorption spectrometry. The adoption of a background electrolyte consisting of 10mM imidazole adjusted to pH 3.75 by the addition of oxalic acid allowed baseline separation of Na from other milk cations and from Li ion, which was adopted as an internal standard. Method validation was performed and the results for linearity, precision, limit of detection, limit of quantification, and recovery are presented. The procedure was tested on commercial milk samples differing in fat content (whole, semiskimmed, and skimmed) and processing conditions (pasteurization, UHT sterilization, and microfiltration). The reliability of the method was confirmed for different varieties of cheese and other milk products. The method enables the routine measurement of Na content by a rapid and accurate capillary zone electrophoresis procedure.

The Traditional Cheeses of Turkey: Central Anatolian Region

The making of the majority of cheeses is based on ancient traditions. Anatolia possesses a rich cheese-making culture and this review aims to collate the Central Anatolian Region cheese varieties. Research carried out in this context shows that there are 16 different varieties of cheese in this region. These are: Divle Tulum Cheese, Küp (Jar) Cheese, Gölbaşı Tulum Cheese, Çanak (Pan) Cheese, Gödelek Cheese, Çömlek (Pot) Cheese, Kayseri Pot Cheese, Küpecik Cheese, Çökelek With Pepper, Çepni Tulum Cheese, Ayaş Basma (Pressed) Cheese, Pesküten, Konya Molded Cheese, Ereğli Cloth Tulum Cheese, Karaman Tulum Cheese, and Ekşi (Sour) Cheese. In this publication, the production methods of these cheeses, as well as their properties, and for some, the chemical and microbiological properties are presented.

Article

Relationships between functional properties and variables obtained with a temperature- sweep dynamic shear test of twenty different varieties of cheese were evaluated. Flowability was assessed using a modified Schreiber test and stretchability by a method involving vertical traction. The dynamic shear test provides a typical profile for each cheese variety, a profile that might be related to the different cheese-making processes, and especially to the heating and mechanical treatments influencing further the response of the cheese matrix by itself in conditions of cooking use. Principal component analysis (PCA) gave evidence of complex and non-linear relationships between the characteristics of the dynamic shear profile and the stretchability or meltability indices. A significant, but weak, link between pH and stretchability was observed. PCA separated cheeses by their cheese-making technology. The effects of the technological factors for the different types of cheese varieties on their functional properties suggest the possibility either of predicting these properties or of changing the processes in order to create new products with new functionalities. Functional property / dynamic shear test / Schreiber test / stretchability test / cheese

Rapid Simultaneous Determination of Organic Acids, Free Amino Acids, and Lactose in Cheese by Capillary Electrophoresis

A capillary electrophoresis (CE) method for the simultaneous separation of 11 metabolically important organic acids (oxalic, formic, citric, succinic, orotic, uric, acetic, pyruvic, propionic, lactic, and butyric), 10 amino acids (Asp, Glu, Tyr, Gly, Ala, Ser, Leu, Phe, Lys, and Trp), and lactose has been optimized, validated, and tested in dairy products. Repeatability and linearity were calculated for each compound, with detection limit values as low as 0.2·10−2 mM for citric acid and Gly. The method was applied to analyze yogurt and different varieties of commercial cheeses. This method yielded specific CE patterns for different varieties of cheese. Also, it has been shown to be sensitive enough to measure small changes in composition of some of those compounds in fresh cheese stored under accelerated ripening conditions for 2 d at 32°C (e.g., from 1728.3±45.0 to 1166.7±4.5 mg/100g of DM in the case of lactose, or from 23.5±0.6 to 76.8±16.7 mg/100g of DM in the case of acetic acid).

Presence of peptidase activities in different varieties of cheese.

Lactic acid bacteria (LAB) counts, PepX activity towards H-Phe-Pro-beta NA, and aminopeptidase activity towards H-Arg-beta NA. HCl, H-Lys-beta NA, H-Leu-beta NA, H-Pro-beta NA, H-Glu-beta NA derivatives have been evaluated in 32 commercial samples of cheese, one processed cheese, and one yoghurt. The presence of intracellular exo-peptidase activities in cheese extracts free from bacterial cells was detected, even after 1 year of ripening. An inverse ratio between the presence of viable lactic microflora and peptidase activity in the cheese extracts was observed. The importance of LAB starter exo-peptidases in the degradation of casein oligopeptides, and the key role of autolysis in the release of peptidases in the cheese, are discussed.

Intervarietal comparison of proteolysis in commercial cheese

Proteolysis in different varieties of cheese, i.e. Cheddar, British, Dutch and Swiss types and Italian varieties, was compared by polyacrylamide gel electrophoresis (PAGE) and reverse-phase high-performance liquid chromatography (RP-HPLC). Urea-PAGE of the water-insoluble fraction (WISF) of cheese appeared to be unable to distinguish between Cheddar and Dutch-type cheeses, whereas it could be used to distinguish Emmental from Parmesan and both of these from Cheddar and Dutch types. Urea-PAGE of the 70%-ethanol-insoluble fraction of the water-soluble extract (WSE) showed large inter-varietal differences but there were also some intra-varietal differences. RP-HPLC of the 70%-ethanol-soluble and -insoluble fractions of the WSEs of cheeses was more effective than urea-PAGE of the WISFs or of the 70%-ethanol-insoluble fraction of the WSEs of cheeses when classifying cheese according to variety. However, analysis of a larger number of cheese samples is required to verify this result. One of the problems with using either urea-PAGE or RP-HPLC to identify cheese is that the characteristics analysed by these techniques change as ripening progresses.

Rapid procedure for detecting enterohemorrhagic Escherichia coli O157:H7 in food

A sensitive, specific procedure was developed for detecting Escherichia coli O157:H7 in food in less than 20 h. The procedure involves enrichment of 25 g of food in 225 ml of a selective enrichment medium for 16 to 18 h at 37 degrees C with agitation (150 rpm). The enrichment culture is applied to a sandwich enzyme-linked immunosorbent assay (ELISA) with a polyclonal antibody specific for E. coli O157 antigen as the capture antibody and a monoclonal antibody specific for enterohemorrhagic E. coli of serotypes O157:H7 and O26:H11 as the detection antibody. The ELISA can be completed within 3 h. The sensitivity of the procedure, determined by using E. coli O157:H7-inoculated ground beef and dairy products, including different varieties of cheese, was 0.2 to 0.9 cell per g of food. A survey of retail fresh ground beef and farm raw milk samples with this procedure revealed that 3 (2.8%) of 107 ground beef samples and 11 (10%) of 115 raw milk samples were positive for E. coli O157:H7. Most-probable-number determinations revealed E. coli O157:H7 populations of 0.4 to 1.5 cells per g in the three ground beef samples. In addition to being highly specific, sensitive, and rapid, this procedure is easy to perform and is amenable to use by laboratories performing routine microbiological testing.

Milk-Clotting Enzymes. 1. Proteolysis During Cheese Making in Relation to Estimated Losses of Yield

Cheddar cheese was made in beakers (by the process for aged cheese) to compare milkclotting enzymes for their effect on proteolysis during coagulation, cooking, and cheddaring. All enzymes released more N into whey during cooking and cheddaring than calf rennet except the equal mixture of calf rennet and swine pepsin during cheddaring. Levels of true protein were the same in whey during cooking and during cheddaring with all enzymes, except those from Bacillus polymyxa showed proteolysis of whey proteins. Hydrolysis of casein occurred after cooking and during cheddaring with all enzymes including calf rennet. Data were discussed with respect to protein recoveries in cheese from ultrafiltered milk.Probable reductions in yield were estimated using a factor of 27.06 for converting estimated casein reductions in milk to percentage of yield losses. This factor assumes: the prices of milk fat and cheese are equal; cheddar cheese of the same composition is made of .37 moisture and .017 salt; whey contained .065 fat-free, curd-free solids; milk contained .036 fat and .ON64 casein or was standardid to the same casein:fat ratio, considering casein losses; and yield of cheese was 9.834 kg100kg milk. Yield losses (± least significant differences), compared with losses of calf rennet, were estimated as: bovine pepsin, –.14 (± .08); equal mixture of calf rennet and swine pepsin, –.07 (± .08); Mucor pusillus, –.49 (± .11); M. miehei (preparation I), –.63 (± .11); M. miehei, (preparation II), –.68 (± .12); Endothia parasitica, –1.24 (± .32); B. polymyxa, 4.79% (± .32%). These would be economically important losses of concern to cheese makers.Special attention was given to replications and statistical analyses to reduce least significant differences: quadruplicate Kjeldahl analyses, 6 to 12 replicate trials per enzyme, with comparison among enzymes within days.Comparison of levels of N in whey during simulated cheese making in beakers is suggested for comparing milk-clotting enzymes for their effect on yield of different varieties of cheese. This could be considered a basic loss of yield; losses of curd and fat in whey would be additional losses.

Examination of some fermented foods for the presence of apparent total N-nitroso compounds.

The fermented foods yoghurt, bread and cheese were analysed for the presence of apparent total N-nitroso compounds (ATNC) by a group-selective procedure involving direct chemical denitrosation and chemiluminescence detection of the released nitric oxide. The levels of ATNC were below the 20 micrograms(N-NO)/kg detection limit in all 20 yoghurts, 23 of the 24 bread samples and 28 out of 31 different varieties of cheese analysed. ATNC were detected in most of those cheese samples manufactured with added nitrate, including Edam, Gouda and Havarti, in concentrations ranging from 30 to 210 micrograms(N-NO)/kg.

Nutrient content of milk and milk products: Vitamins of the B complex and vitamin C in retail cheeses

AbstractA survey was undertaken to update and extend information on the water‐soluble vitamin content of 42 different varieties of cheese on retail sale in the UK.

Relation of Cheese-Making Operations to Survival and Growth of Staphylococcus aureus in Different Varieties of Cheese

Summary Tests were made to determine the effect of manufacturing procedures for specific varieties of cheese on the growth and survival of Staphylococcus aureus (MF31) organisms added to milk at the start of the process. The staphylococcal count was approximately 1×10 5 /ml milk. Cheddar, Colby, Swiss-type, Limburger, and Cottage cheese by two methods were made. Conditions of manufacture of each variety were favorable for the growth of S. aureus and significant increases occurred at specific stages. In general, the organisms were concentrated in the curd and increased in number until the cheese was salted. After pressing the curd, another increase might occur during the first 21 days of aging. A decrease would then take place, which generally continued throughout aging. At no time, however, did the S. aureus count become zero during aging. Staphylococci were not recovered from fresh Cottage cheese after it had been cooked at 130F for 40min at pH 4.5. However, when the curd was stored dry or creamed for ten days at either 40 or 50F, viable S. aureus organisms were recovered. Nevertheless, the manufacturing procedure for Cottage cheese was the only effective one in destroying S. aureus .

274. Preliminary experiments on the vapour pressure of dairy products

1. Methods for measuring the vapour pressure of cheese and milk are discussed, and vapour pressure/moisture curves are given for a number of different varieties of cheese. The progressive artificial damping and drying of cheese produces no appreciable hysteresis in these curves.2. The vapour pressure curve is much influenced by the amount of salt in the cheese, but differences between varieties cannot be accounted for entirely in terms of differences in NaCl content.3. A preliminary experiment on the relationship between vapour pressure of Stilton cheese and amount of blueing indicated that such a relationship does in fact exist but that a much larger experiment is required before the connexion is fully understood.4. Preliminary experiments on the measurement of the vapour pressure of milk, although interrupted at rather an early stage, showed that, even so, additions of 2–3% of water in milk can be satisfactorily detected.