Brine Cheese Research Articles

Biogenic amines in Iranian white brine cheese: modelling and optimisation of processing factors

The simultaneous effects of processing factors such as ripening time (25–75 days), ripening temperature (4–14 °C) and brine concentration (10–13%) on biogenic amines content, proteolysis and sensory score of Iranian white brine cheese were studied, in 12 cheeses. Response surface methodology (RSM) was used to minimise biogenic amines content. At low level of ripening time, biogenic amines content decreased with increasing levels of brine concentration but at high level of ripening time, brine concentration had inverse effect. Ripening time showed quadratic effect on biogenic amines content. Based on biogenic amines content and sensory score, the optimum conditions were 13% brine and ripening at 9–14 °C for 43–65 days.

Obtaining functional fermented beverages by using the kefir grains

In this experimental work were developed beverages from products obtained after processing of milk. There have been opportunities for functional beverages through the use of probiotic microorganisms contained in kefir grains and whey from the manufacture of Bulgarian brine cheese and ultrafiltrate from milk or whey. Observed and analyzed is the rate of lactic acid fermentation and established appropriate conditions for development of kefir grains in obtaining fermented beverages. Applied is non-contacts ultrasound method for diagnosis of beverages. Determined is the technological sequence of production stages, physicochemical and microbiological characteristics during manufacture and storage of functional product.

Application of high-pressure treatment on ovine brined cheese: Effect on composition and microflora throughout ripening

Abstract Ovine brined cheese was high-pressure (HP) treated at 200 or 500 MPa for 15 min at 20 °C on the 15th day of ripening. Compared to control cheese, HP treatment did not affect significantly ( P > 0.05) the pH values, moisture, fat in dry matter, protein in dry matter and salt in moisture contents of cheeses at 90 days. The counts of total aerobic mesophilic bacteria, thermophilic lactococci, thermophilic lactobacilli and non starter lactic acid bacteria (NSLAB) were not affected by HP treatment of cheese at 200 MPa throughout ripening. After 90 days of ripening, the same microbial groups in cheese treated at 500 MPa were about 1.2, 3.6, 2.1 and 4 log units lower than in control cheese respectively. Coliforms were reduced faster at non detectable levels in HP treated cheeses than in control cheese. Regarding the bacterial enzymatic activities in cheese, aminopeptidase activity (Apep) was marginally favoured by both HP treatments. However, its activity was decreased at 90 days due probably to loss in brine. In contrast, lactate dehydrogenase (LDH) activity, following the bacteria cell lysis, was negatively affected by HP treatment at 500 MPa throughout ripening. Industrial relevance The data obtained from this work suggest that application of HP treatment under optimized conditions on ovine cheese in brine can be used to reduce effectively the undesirable microbial load in it and to cause moderate enhancement of aminopeptidase activity, without modifying its composition.

Chemical composition, mineral content and cholesterol levels of some regular and reduced-fat white brined cheeses and strained yogurt (Labneh)

White brined cheeses and strained yogurt (Labneh) are the most popular dairy products in the Eastern Mediterranean. However, scant data are available on the nutrient profiles of these products. In the present work, 38 samples of regular and reduced-fat varieties of four white brined cheeses (Akkawi, Halloumi, Double Creme and Braided) and Labneh, produced from cow’s milk, were analyzed for basic nutrients (water, protein, fat, ash and lactose), cholesterol and selected minerals (Na, Ca, K, Mg, P and Zn). The moisture contents of Labneh (78.6 g·100 g−1 ) and Double Creme (60.3 g·100 g−1 ) were higher than those of Akkawi, Halloumi and Braided cheeses (46.6–55.1 g·100 g−1 ). The fat content of full-fat Labneh was 8.8 g·100 g−1 while the full-fat brined cheeses contained fat levels between 18.3 and 23.9 g·100 g−1 . Protein contents ranged between 8.9 and 24.8 g·100 g−1 . Cholesterol strongly correlated with fat content and an increase in cholesterol/fat ratios was observed with decreasing fat levels. Sodium contents ranged between 151 and 5012 mg·100 g−1 while Ca levels ranged between 43 and 921 mg·100 g−1 . The moisture contents indicated that Double Creme was a soft cheese while Akkawi, Halloumi and Braided cheeses were firm/semi-hard cheeses. The fat levels in dry matter (FDM) revealed that only full-fat Double Creme cheese with a FDM of 48 can be classified as full-fat while the other cheeses can be classified as medium fat, partially skimmed or skim. These data will be of use to dairy scientists and technologists, dietitians and bodies concerned with promoting healthier dietary practices.

Isoflux ® ceramic membranes — Practical experiences in dairy industry

Three marketed ceramic microfiltration membranes working in so called 'Uniform Transmembrane Pressure' mode with special focus on ISOFLUXR concept have been presented in this paper. Microfiltration of liquids treated in dairy industry has been described in the examples of milk and cheese brine. Industrial results of spore and bacteria removal from consumer milk (ESL milk) and cheese brine along with chosen economical aspects of investment/operation cost of working MF plants have been reported. Advantages of the micelar casein/whey protein separation process and examples of industrial applications of products being results of such a separation process along with a sample description of industrial milk protein separation plants have been reported.

Influence of brine concentration and temperature on composition, microstructure, and yield of feta cheese

The protein matrix of cheese undergoes changes immediately following cheesemaking in response to salting and cooling. Normally, such changes are limited by the amount of water entrapped in the cheese at the time of block formation but for brined cheeses such as feta cheese brine acts as a reservoir of additional water. Our objective was to determine the extent to which the protein matrix of cheese expands or contracts as a function of salt concentration and temperature, and whether such changes are reversible. Blocks of feta cheese made with overnight fermentation at 20 and 31°C yielded cheese of pH 4.92 and pH 4.83 with 50.8 and 48.9g/100g of moisture, respectively. These cheeses were then cut into 100-g pieces and placed in plastic bags containing 100g of whey brine solutions of 6.5, 8.0, and 9.5% salt, and stored at 3, 6, 10, and 22°C for 10 d. After brining, cheese and whey were reweighed, whey volume measured, and cheese salt, moisture, and pH determined. A second set of cheeses were similarly placed in brine (n=9) and stored for 10 d at 3°C, followed by 10 d at 22°C, followed by 10 d at 3°C, or the complementary treatments starting at 22°C. Cheese weight and whey volume (n=3) were measured at 10, 20, and 30 d of brining. Cheese structure was examined using laser scanning confocal microscopy. Brining temperature had the greatest influence on cheese composition (except for salt content), cheese weight, and cheese volume. Salt-in-moisture content of the cheeses approached expected levels based on brine concentration and ratio of brine to cheese (i.e., 4.6, 5.7 and 6.7%). Brining at 3°C increased cheese moisture, especially for cheese with an initial pH of 4.92, producing cheese with moisture up to 58g/100g. Cheese weight increased after brining at 3, 6, or 10°C. Cold storage also prevented further fermentation and the pH remained constant, whereas at 22°C the pH dropped as low as pH 4.1. At 3°C, the cheese matrix expanded (20 to 30%), whereas at 22°C there was a contraction and a 13 to 18g/100g loss in weight. Expansion of the protein matrix at 3°C was reversed by changing to 22°C. However, contraction of the protein matrix was not reversed by changing to 3°C, and the cheese volume remained less than what it was initially.

Effect of Zataria multiflora Boiss. essential oil on growth and aflatoxin formation by Aspergillus flavus in culture media and cheese

The effect of Zataria multiflora Boiss. essential oil (EO) against growth, spore production and aflatoxin formation by Aspergillus flavus ATCC 15546 was investigated in synthetic media as well as Iranian ultra-filtered white cheese in brine. EO effectively inhibited radial growth and spore production on potato dextrose agar (PDA) in a dose-dependent manner. At 200 ppm, the radial growth and sporulation reduced by 79.4% and 92.5%, respectively. The growth was completely prevented at EO ⩾ 400 ppm on PDA, and minimum fungicidal concentration (MFC) of the oil was estimated at 1000 ppm. The oil also significantly suppressed mycelial growth and aflatoxin synthesis in broth medium at all concentrations tested ( P < 0.05). At 150 ppm of EO, the mycelial growth and aflatoxin accumulation reduced by 90% and 99.4%, respectively. The EO at all concentrations tested, had an inhibitory effect against radial fungal growth and aflatoxin production by A. flavus in cheese. However, no concentration of EO examined was able to completely inhibit the growth and aflatoxin production in cheese. The results suggested the potential substitution of the antifungal chemicals by this EO as a natural inhibitor to control the growth of molds in foods such as cheese.

Fate of Aflatoxin M1 during Manufacture and Storage of Feta Cheese

The effect of feta cheese manufacture on aflatoxin M(1) (AFM(1)) content was studied using an enzyme immunoassay technique. Feta cheese was made from milk spiked with 1 and 2 microg AFM(1) per kilogram milk. Pasteurization at 63 degrees C for 30 min caused <10% destruction of AFM(1). During cheese making, the remaining AFM(1) in milk was partitioned between curd and whey with two-thirds retained in the curd and one-third going into the whey. Cheeses were then stored for 2 mo in 8%, 10%, and 12% brine solutions at 6 and 18 degrees C. There was a 22% to 27% reduction of AFM(1) during the first 10 d of storage, with slightly more loss as salt concentration increased and when the cheese was stored at 18 degrees C. Further storage caused only slight decrease in AFM(1) and after 30 d of brining there was no difference in AFM(1) content of the cheese based upon salt concentration of the brine. At 18 degrees C, no further losses of AFM(1) occurred after 30 d, and at 6 degrees C, there was continued slight decrease in AFM(1) levels until 50 d. After 60 d of brining, there was a total loss of 25% and 29% of the AFM(1) originally present for cheese brined at 6 and 18 degrees C, respectively. Thus, the combination of pasteurization, conversion of milk into feta cheese, and at least 50 d storage of cheese in brine caused a total loss of about 50% of the AFM(1) originally present in the raw milk.

Study of organic acids, volatile fraction and caseins of a new Halloumi‐type cheese during ripening in whey brine

SummaryOrganic acids, fat hydrolysis, volatile compounds and sensory characteristics of a new brine cheese which combines characteristics of Halloumi and Feta cheeses during its ripening in whey brine (100g NaCl L−1) were studied. Thermotolerant protease of Mucor miehei as a coagulant enzyme and a mixture of thermotolerant starter cultures Enterococcus faecium 0165 (0.5% w/w) and Lactobacillus casei 80 10D were used. Good quality new Halloumi‐type cheese was produced with higher proteolysis than traditional Halloumi cheese kept in whey brine. The volatile compounds identified comprised alcohols, aldehydes, ketones, acids, esters, hydrocarbons and sulphur compounds. Ethanol was the dominant volatile compound determined. Lactic acid was the dominant acid produced; its concentration increased during ripening, reaching a maximum value of 9929 mg kg−1 at day 30. Acetic acid was also found in high amounts, which increased during cheese ripening. Lipolysis of cheese was not intense. The most abundant acids of the mature cheese were palmitic, oleic and acetic acid. The Halloumi‐type cheese scored higher in the sensory analysis when fresh than did the mature cheese.

Virulent Bacteriophage for Efficient Biocontrol of Listeria monocytogenes in Ready-To-Eat Foods

Food-borne Listeria monocytogenes is a serious threat to human health, and new strategies to combat this opportunistic pathogen in foods are needed. Bacteriophages are natural enemies of bacteria and are suitable candidates for the environmentally friendly biocontrol of these pathogens. In a comprehensive set of experiments, we have evaluated the virulent, broad-host-range phages A511 and P100 for control of L. monocytogenes strains Scott A (serovar 4b) and WSLC 1001 (serovar 1/2a) in different ready-to-eat (RTE) foods known to frequently carry the pathogen. Food samples were spiked with bacteria (1 x 10(3) CFU/g), phage added thereafter (3 x 10(6) to 3 x 10(8) PFU/g), and samples stored at 6 degrees C for 6 days. In liquid foods, such as chocolate milk and mozzarella cheese brine, bacterial counts rapidly dropped below the level of direct detection. On solid foods (hot dogs, sliced turkey meat, smoked salmon, seafood, sliced cabbage, and lettuce leaves), phages could reduce bacterial counts by up to 5 log units. Variation of the experimental conditions (extended storage over 13 days or storage at 20 degrees C) yielded similar results. In general, the application of more phage particles (3 x 10(8) PFU/g) was more effective than lower doses. The added phages retained most of their infectivity during storage in foods of animal origin, whereas plant material caused inactivation by more than 1 log(10). In conclusion, our data demonstrate that virulent broad-host-range phages, such as A511 and P100, can be very effective for specific biocontrol of L. monocytogenes in contamination-sensitive RTE foods.

Effects of γ-irradiation on Listeria monocytogenes population, colour, texture and sensory properties of Feta cheese during cold storage

Feta, a white brine cheese, was produced and contaminated with Listeria monocytogenes. Contamination occurred either at the beginning (pre-process contamination) or at the end of Feta manufacturing (post-process contamination). In the first case the milk was contaminated with 10 3 cfu/ml, and 2 months later, in the final product, the L. monocytogenes population was approximately 10 5 cfu/g. In the second case, the brine (NaCl, 7% w/v), in which the Feta was packaged, was contaminated with 10 3 cfu/ml. Contaminated Feta samples were vacuum-packaged and exposed to irradiation doses of 1.0, 2.5 and 4.7 kGy and stored at 4 °C for a month. In the pre-process contaminated samples none of the irradiation doses eliminated L. monocytogenes; however the highest dose reduced the viable population to a level which is in compliance with EC regulations. In the post-process contamination, the 2.5 kGy and 4.7 kGy doses reduced L. monocytogenes counts below the detection limit. Irradiation had no effect on the texture of Feta. Irradiation at 4.7 kGy increased Feta's redness and decreased its yellowness and lightness. Sensorial analyses showed that at the 4.7 kGy dose, the aroma profile of Feta was temporarily affected, since it was restored after 30 days of cold storage.

Minimization of aflatoxin M1 content in Iranian white brine cheese

A chemometric approach was used to minimize the aflatoxin M1 (AFM1) content of Iranian white brine cheese. The effects of processing factors such as renneting temperature (30–40°C), cutting size (0.5–1 cm), stirring time (10–20 min), press time (1–2 h), curd size (64–256 cm3) and saturated brine pH (4.6–6) on the AFM1 content of the cheese curds were explored. Renneting temperature, press time and saturated brine pH were, respectively, the most significant factors. The aflatoxin content of the cheese samples decreased with increasing renneting temperature and press time. Lowering of the saturated brine pH reduced AFM1 in the cheese curds. Taking account of all of the factors studied, optimum processing conditions for minimization of AFM1 in the cheese curds were: renneting temperature = 39.91°C, cut size = 0.51 cm, stirring time = 17.71 min, press time = 19.48 min, curd size = 73.27 cm3 and saturated brine pH = 4.79.

Simulation of NaCl and KCl mass transfer during salting of Prato cheese in brine with agitation: a numerical solution

The association of dietary NaCl with arterial hypertension has led to a reduction in the levels of this salt in cheeses. For salting, KCl has been used as a partial substitute for NaCl, which cannot be completely substituted without affecting product acceptability. In this study a sensorially adequate saline solution (NaCl/KCl) was simultaneously diffused during salting of Prato cheese in brine with agitation. The simultaneous multicomponent diffusion during the process was modeled with Fick's second generalized law. The system of partial differential equations formed was solved by the finite element method (FEM). In the experimental data concentration the deviation for NaCl was of 7.3% and for KCl of 5.4%, both of which were considered acceptable. The simulation of salt diffusion will allow control and modulation of salt content in Prato cheese, permitting the prediction of final content from initial conditions.

Optimizing Sensorial Quality of Iranian White Brine Cheese Using Response Surface Methodology

ABSTRACT: Response surface methodology was used to evaluate the effects of processing variables, such as ripening time (20 to 60 d), ripening temperature (6 to 10°C), level of rennet added (1 to 2 g/100 kg milk), and brine concentration (8% to 14%, w/v), on the sensorial quality of Iranian pickled cheese (feta type). Optimization of sensorial quality was performed by canonical analysis to derive the stationary point. Based on contour plots and canonical analysis, optimum conditions were ripening time 32 d, ripening temperature 8.3°C, level of rennet added 1.6 g/100 kg of milk, and brine concentration 11%. Predicted sensory score was 20.76 from maximum score of 25.

Multicomponent diffusion modeling and simulation in prato cheese salting using brine at rest: The finite element method approach

The relationship between NaCl in the diet and hypertension has stimulated a partial substitution by KCl in cheese, however, it is very important to guarantee an adequate proportion of NaCl/KCl, and also the homogeneous distribution of these salts is necessary to maintain the final quality of the product. Therefore, the use of models that simulate multicomponent diffusion during the mixed salting of cheese with a reduced quantity of NaCl is important to control the quality. The multicomponent diffusion that occurred during the salting of prato cheese in brine at rest, of adequate salt concentration, was modeled and simulated in this study. The model was based on Fick’s second law generalized for simultaneous diffusion. The finite element method (FEM) was used with a three-dimensional model. The deviation of NaCl experimental concentration data was 2.7% and 6.5% for KCl. The salting simulation, through FEM, allowed a potential increase in production (reducing the salting time), modulating the process to the required salt concentration.

Composition, Microstructure, and Surface Barrier Layer Development During Brine Salting

The goal of this study was to characterize the changes in chemical composition, porosity, and structure that occur at the surface of a block of brine-salted cheese and their relationship to the rate at which salt is taken up from the brine. To create a difference in composition, salt uptake, and barrier layer properties, identical blocks of Ragusano cheese were placed in saturated and 18% salt brine at 18°C for 12 d. The overall moisture content and porosity decreased, whereas salt and salt in moisture content increased near the surface of blocks of brine-salted Ragusano cheese for all treatments. The general appearance of the microstructure of the surface of the blocks of brine-salted cheese was much more compact than the microstructure 1mm inside the block at both brine concentrations. Large differences in porosity of the barrier layer were produced by brine-salting cheese in 18% vs. saturated brine, with cheese in saturated brine having much lower porosity at the surface and taking up much less salt during brining. The macro network of water channels within the microstructure of the cheese was less open near the surface of the block for cheese in both saturated and 18% brine after 4 d. However, no large differences in the size of the macro channels in the cheese structure due to the difference in brine concentration were observed by scanning electron microscopy. It is possible that the shrinkage of the much smaller pore structure within the casein matrix of the cheese is more important and will become more limiting to the rate of salt diffusion. Further microstructure work at higher resolution is needed to answer this question. The calculated decrease in porosity at the exterior 1-mm portion of the block was 50.8 and 29.2% for cheeses that had been in saturated vs. 18% brine for 12 d, respectively. The difference in brine concentration had a very large impact on the salt in moisture content of the cheese. The exterior of the cheese in 18% brine reached a salt in moisture content almost identical to that of the brine very quickly (17.3% at 4 d), whereas the salt in moisture content at the surface of the cheese block in saturated brine was only 11.9% at 4 d. There appears to be some critical concentration of salt in brine above which there is a large negative impact on salt uptake due to the creation of a barrier layer at the surface of the block of cheese.

Modeling of proteolysis and lipolysis in Iranian white brine cheese

The simultaneous effects of processing variables such as ripening time (20–60 days), ripening temperature (6–10 °C), level of rennet added (1–2 g/100 kg milk) and brine concentration (8–14%, w/v) on the proteolysis, lipolysis and sensory score of Iranian white brined cheese (Feta type) were explored by the means of response surface methodology. The most important effect in proteolytical terms was produced by ripening temperature and ripening time in linear form, but level of rennet added and brine concentration were also significant at the 5% level. In terms of lipolysis, ripening time was dominant factor in both linear and quadratic forms; quadratic effect of ripening temperature was greater than its linear effect. Based on sensory score, optimum conditions were: ripening temperature = 6.7 °C, ripening time = 49.5 days, level of rennet added = 1.4 g/100 kg of milk and brine concentration = 10.9%, w/v.

Basic nutrients and element contents of white cheese of diyarbakır in turkey

Basic nutrients, moisture, fat and protein, and concentrations of 15 major and trace elements in total and fatty parts of Diyarbakır white cheese were evaluated for compositional differences. Elements were determined using inductively coupled plasma atomic emission spectrometry, while fat was determined by supercritical extraction and protein by protein/nitrogen analyzer. Diyarbakır brine and melt cheeses have lower humidity and higher protein than market brine cheese samples. The fat level was 14–18% for all cheeses. The levels of investigated major and trace elements were much higher in three types of cheese samples. Except for Zn and Mn, the other investigated elements were found in fairly low concentrations and at variable ranges in the fatty part of cheese samples. The elements, Mg among major elements and Fe among trace elements, were highest in that part. Na and Ca as major and Zn, Fe and Al as trace elements were found at maximum levels, especially in Diyarbakır melt cheese. Also, levels correlations between basic nutrients, basic nutrients and elements and element pairs were investigated.

Influence of the Temperature of Salt Brine on Salt Uptake by Ragusano Cheese

The influence of temperature (12, 15, 18, 21, and 24°C) of saturated brine on salt uptake by 3.8-kg experimental blocks of Ragusano cheese during 24 d of brining was determined. Twenty-six 3.8-kg blocks were made on each of three different days. All blocks were labeled and weighed prior to brining. One block was sampled and analyzed prior to brine salting. Five blocks were placed into each of five different brine tanks at different temperatures. One block was removed from each brine tank after 1, 4, 8, 16, and 24 d of brining, weighed, sampled, and analyzed for salt and moisture content. The weight loss by blocks of cheese after 24 d of brining was higher, with increasing brine temperature, and represented the net effect of moisture loss and salt uptake. The total salt uptake and moisture loss increased with increasing brine temperature. Salt penetrates into cheese through the moisture phase within the pore structure of the cheese. Porosity of the cheese structure and viscosity of the water phase within the pores influenced the rate and extent of salt penetration during 24 d of brining. In a previous study, it was determined that salt uptake at 18°C was faster in 18% brine than in saturated brine due to higher moisture and porosity of the exterior portion of the cheese. In the present study, moisture loss occurred from all cheeses at all temperatures and most of the loss was from the exterior portion of the block during the first 4 d of brining. This loss in moisture would be expected to decrease porosity of the exterior portion and act as a barrier to salt penetration. The moisture loss increased with increasing brine temperature. If this decrease in porosity was the only factor influencing salt uptake, then it would be expected that the cheeses at higher brine temperature would have had lower salt content. However, the opposite was true. Brine temperature must have also impacted the viscosity of the aqueous phase of the cheese. Cheese in lower temperature brine would be expected to have higher viscosity of the aqueous phase and slower salt uptake, even though the cheese at lower brine temperature should have had a more porous structure (favoring faster uptake) than cheese at higher brine temperature. Therefore, changing brine concentration has a greater impact on cheese porosity, while changing brine temperature has a larger impact on viscosity of the aqueous phase of the cheese within the pores in the cheese.

Investigation on ropiness development by isolates of the genera Lactobacillus, Alcaligenes and Feta cheese starter cultures

Lactobacillus pseudoplantarum and Alcaligenes spp. were isolated from ropy brine and milk, respectively, and their ability to develop ropiness was investigated. Vigorous ropiness was developed by L. pseudoplantarum in whey with 7% NaCl, after 21 days of incubation at 15°C. Alcaligenes spp. developed ropy colonies on PCA, containing up to 2% NaCl at incubation temperature of 4°C and 15°C. Also reconstituted skim milk inoculated with Alcaligenes spp. became ropy after 5–13 days of incubation only at 4°C. Ropiness was not noticed when NaCl was added to the skim milk. In order to investigate the ropiness development in Feta cheese brine, a commercial yoghurt culture was used to make Feta cheese in combination with the two bacteria isolates and a ropy yoghurt culture. The results revealed that only the ropy yoghurt culture and not the normal one, developed very high ropiness in brine during ripening at 15°C. The results also showed that Alcaligenes spp. and L. pseudoplantarum intensified ropiness of brine. To avoid ropiness, it is recommended that yoghurt starter cultures used for Feta should be selected and bacterial contaminants that could cause ropiness in brine should be eliminated.