Turkish White Cheese Research Articles

Use of corn oil in the production of Turkish white cheese.

The use of corn oil in white cheese production instead of milk fat was investigated and its effects on the quality parameters of cheese were studied. It was demonstrated that the use of corn oil significantly affected the levels of dry matter, fat in dry matter, protein, salt in dry matter and titratable acidity and pH value of samples (p < 0.05). The water-soluble nitrogen based ripening indices of cheeses increased throughout the ripening period. However, there were not large quantitative differences among the peptide profiles of all the cheese samples. The polyunsaturated fatty acids (PUFA), the polyunsaturated to saturated fatty acid ratios (PUFA/SFA) and total cis fatty acid contents were found to be higher whilst the saturated fatty acid and trans fatty acid content were found to be lower than those of the control cheese (p < 0.05). It was found that the use of corn oil instead of milk fat in cheese production decreased the cholesterol content of the cheese samples (p < 0.05). The sensory scores of corn oil cheese were almost similar to the control cheese. The results indicated that corn oil utilization in cheese production has commercial potential in overcoming the defects related to fat reduction.

EFFECT OF ACID ADAPTATION AND DIFFERENT SALT CONCENTRATIONS ON SURVIVAL OF LISTERIA MONOCYTOGENES IN TURKISH WHITE CHEESE

Survival of acid-adapted and nonacid adapted Listeria monocytogenes in Turkish white cheese with different salt concentrations (3.8 and 6.7% NaCl) was investigated. Cheese blocks were inoculated with L. monocytogenes and stored at 4C for 15 days. Samples were taken on different days and analyzed for the numbers of the pathogen, and the samples were challenged with simulated gastric fluid (SGF) for determining acid tolerance. There was no significant differences between the numbers of acid-adapted and nonadapted L. monocytogenes cells regardless of the salt concentration on sampling days (P > 0.05). Challenge in SGF revealed that there was no significant difference between acid-adapted and nonadapted bacteria in cheese with 3.8% NaCl throughout the storage period, while significant (P < 0.05) differences between those cells in cheese with 6.7% NaCl were found after day 5. These results suggest that acid-adapted L. monocytogenes exposed to high salt concentration such as 6.7% may have an advantage in SGF. PRACTICAL APPLICATIONS Evaluation of potential stress responses of pathogens in food is important to understand the behavior of pathogens that can survive under stresses. As an environmental contaminant, Listeria monocytogenes may acquire adaptation to low acid conditions in cheese plants. Our results suggested that although there was no significant difference between acid-adapted and nonadapted cells both in industrial (3.8% salt) and traditional (6.7% salt) white cheese, salt concentration significantly affected the survival of acid-adapted cells in simulated gastric fluid (pH 2.3). These findings may indicate that L. monocytogenes, which is adapted to acid before contaminating high salt cheeses, may survive in stomach and cause infection. It can be said that increased salt concentration in cheese may not provide a barrier against acid-adapted L. monocytogenes.

INFLUENCE OF PACKAGING SYSTEMS ON THE BIOCHEMICAL CHARACTERISTICS AND VOLATILE COMPOUNDS OF INDUSTRIALLY PRODUCED TURKISH WHITE CHEESE*

Full-fat Turkish white cheese was manufactured in an industrial scale and ripened for 90 days after packaging in polystyrene container with brine containing 12% salt or cryovac plastic material under vacuum. White cheese packaged with cryovac container had higher contents of total solids, milk fat, water-soluble nitrogen and lactic acid and lower contents of salt and ash than the cheese packaged in polystyrene container during ripening (P < 0.05). The ripening index and the counts of lactococci and lactobacilli were also higher with cryovac container (P < 0.05). With regard to volatile compounds, a total of 40 components were identified: alcohols (5), aldehydes (3), ketones (7), esters (4), volatile acids (10), hydrocarbons (8) and other compounds (3). Volatile acids were the main components of both Turkish white cheeses. The contents of hexanoic and butanoic acids, dominant acids of cheese in cryovac container, were significantly higher when compared to the cheese in polystyrene cup (P < 0.05). PRACTICAL APPLICATIONS Turkish white cheese was generally ripened for up to 3 months in brine and marketed in can or plastic package containing brine. Recently, cheese molds have been packaged in cryovac container without brine. The chemical composition of cheese on the contents of dry matter, fat, water-soluble nitrogen, salt, lactic acid and the counts of starter bacteria were influenced by packaging system. Ripening index and dominant volatile compounds of cheese were also affected by packaging in polystyrene container with brine containing 12% salt or cryovac plastic material under vacuum.

INFLUENCE OF PACKAGING CONDITIONS ON THE TEXTURAL AND SENSORY CHARACTERISTICS, MICROSTRUCTURE AND COLOR OF INDUSTRIALLY PRODUCED TURKISH WHITE CHEESE DURING RIPENING

ABSTRACT A full‐fat Turkish white cheese was manufactured on an industrial scale and then packaged in a polystyrene container with brine containing 12% salt or a plastic pouch sealed under vacuum, before ripening for 90 days. With regard to textural characteristics, packaging in a plastic pouch resulted in cheeses with significantly higher hardness and cohesiveness (P &lt; 0.05). Scanning electron micrographs showed a more compact and denser protein matrix for the cheese packed in the plastic pouch. Much yellowness was also obtained in cheeses with the plastic pouch (P &lt; 0.05). The experimental cheeses had a similar sensory characteristics in the first 45 days (P &gt; 0.05), but the taste and odor scores decreased in the cheeses packaged with the plastic pouch (P &lt; 0.05) in the 60th and 90th days.PRACTICAL APPLICATIONSTurkish white cheese is generally ripened for 3 months in brine and marketed in a can or polystyrene package containing brine. Recently, cheese molds have been packaged in a plastic pouch without brine. The textural and sensory characteristics and color of the industrially produced Turkish white cheese packaged in a plastic pouch under vacuum or polystyrene container with brine were examined during storage. Higher hardness and cohesiveness was obtained by packaging in a plastic pouch; a more yellow color was also detected in the cheese with a plastic pouch. Sensory characteristics were not influenced by the packaging conditions during the first 45 days of storage, however, the taste and odor scores of the cheese with a plastic pouch were lower after 60 and 90 days.

Utilization of interesterified fat in the production of Turkish white cheese

The chemical, physicochemical, proteolysis, sensory, and texture characteristics of white cheeses made from interesterified fat were examined throughout ripening for 90 days. The water-soluble nitrogen based ripening indexes of cheeses increased throughout the ripening period. However, there were not large quantitative differences between the peptide profiles of the all cheese samples. Cheeses produced by using fully interesterified fat had higher values for hardness, chewiness, and gumminess than that of control cheese (p<0.05). The polyunsaturated to saturated fatty acid ratios of cheeses were increased due to the presence of interesterified fat. The cholesterol values of cheeses decreased at the rate of between 58.83–89.04% depending on interesterified fat addition. In the sensory analysis, similar scores were obtained for both the control cheese and the other cheeses. The results showed that interesterified fat in cheese production could be used to fully or partially replace the milk fat in cheese.

Effects of starter culture combinations using isolates from traditional cheese on the quality of Turkish white cheese

Four types of Turkish white cheese with good curd and acid formation properties were produced, one by using commercial starter culture and the other three by using different combinations of isolates from traditional cheese with no starters added. The effects of using these combinations on quality were determined. Starter culture combinations did not influence the chemical properties of cheese significantly. However, one cheese type produced from combinations of isolates of rural cheese was found to be comparable to the samples produced from commercial starter cultures in terms of sensory and microbial quality. This combination could have promise for white cheese production.

High-Pressure Processing of Turkish White Cheese for Microbial Inactivation

High-pressure processing (HPP) of Turkish white cheese and reduction of Listeria monocytogenes, total Enterobacteriaceae, total aerobic mesophilic bacteria, total molds and yeasts, total Lactococcus spp., and total Lactobacillus spp. were investigated. Cheese samples were produced from raw milk and pasteurized milk and were inoculated with L. monocytogenes after brining. Both inoculated (ca. 107 to 108 CFU/g) and noninoculated samples were subjected to HPP in a high-pressure food processor at 50 to 600 MPa for 5 and 10 min at 25°C. Reductions in L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. in both pasteurized- and raw-milk cheese samples and reductions in total molds and yeasts and total Enterobacteriaceae counts in raw-milk cheese samples increased with increased pressure (P ≤ 0.05). The maximum reduction of the L. monocytogenes count, ca. 4.9 log CFU/g, was obtained at 600 MPa. Because of the highly inhibitory effect of pasteurization, the total molds and yeasts and total Enterobacteriaceae counts for the cheese samples produced from pasteurized milk were below the detection limit both before and after HPP. There was no significant difference in inactivation of L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. under the same treatment conditions for the raw milk and pasteurized milk cheeses and for 5- and 10-min treatment times (P > 0.05). No significant change was detected in pH or water activity of the samples before and after HPP. Our findings suggest that HPP can be used effectively to reduce the microbial load in Turkish white cheese.

Effect of Sorbic Acid and Potassium Sorbate Addition to the Brine on Microbiological and Chemical Properties of Turkish White Cheese during Ripening

In this study, the basic microbiological and chemical properties of Turkish white cheese, containing 300 ppm, 500 ppm and 700 ppm sorbic acid and potassium sorbate, ripened in brine for 90-days at 4 ± 1°C were investigated. Amount of sorbic acid and potassium sorbate added to the brine and ripening time had a significant impact on dry matter, fat, salt, salt in dry matter, titratable acidity, protein, water soluble nitrogen and the concentration of preservatives in cheese (p<0.01).During ripening, preservative diffusion to cheese significantly affected total aerobic mesophilic bacteria, coliform bacteria, and yeast-mould counts of cheese (p<0.01). Results indicated that sorbic acid and potassium sorbate could successfully be used as preservative agents in production of white cheese.

Effect of using interesterified and non‐interesterified corn and palm oil blends on quality and fatty acid composition of Turkish White cheese

SummaryChemically interesterified blends (CIB) and non‐interesterified blends (NIB) of corn and palm oils (75%w/25%w) were studied in the production of Turkish White cheese (TWC) to modify the fatty acid composition of traditional product. Milk fat (3%) was replaced by CIB and NIB for 25%, 50%, 75% and 100%. All cheese groups were ripened at 5 °C for 90 days. Samples were taken from each group after 3, 30, 60 and 90 days and analysed for their basic composition, lipolysis and proteolysis. CIB‐incorporated cheeses showed a higher degree of lipolysis than the control sample and the NIB‐incorporated counterparts. Fatty acid composition and sensory properties of the final product showed that the incorporation of CIB and NIB in TWC improved the nutritional content of the product because it altered the fatty acid composition without any adverse effect on sensorial quality. We concluded that in production of TWC, 50% of milk fat could be successfully replaced with CIB and NIB, preferably CIB, because of its superior sensory quality.

Proteolytical, Chemical, Textural and Sensorial Changes During the Ripening of Turkish White Cheese Made of Pasteurized Cows' Milk

Turkish White Cheese (TWC), manufactured from pasteurized cows' milk, was ripened over 90 days at 4°C, and proteolytical, chemical, textural, and sensorial changes were investigated. The main compositional characteristics of TWC are low content of total solids (TS) (39.80–41.75 g/100 g of cheese), high content of fat (49.12–49.91 g/100 g of TS) and salt (8.69–9.35 g/100 g of TS). The lactose level, pH values, and titratable acidity of samples were found between 0.74–2.05 g/100 g of TS, 4.39–4.68, and 0.73–1.12 g lactic acid/100 g of cheese, respectively. Changes in nitrogenous fractions, Urea-PAGE electrophoregram and RP-HPLC chromatograms showed that TWC undergoes a slight proteolysis. Textural attributes of TWC were significantly (p < 0.05) affected by the ripening period. The highest overall acceptance scores were found at the 60 days of ripening. Bitterness was identified at the end of the 60 and 90 days of ageing period.

Determination of nitrate and nitrite content of Turkish cheeses

± ± ±4.03) mg/kg, respectively. Nitrite was detected 88.11% of cheese samples and mean nitrite values were found between 0.88- 1.64 mg/kg. The highest levels of nitrate and nitrite were determined in the Turkish white cheese samples produced from sheep's milk. The nitrate content of the examined samples of Turkish cheese could be attributed to both external sources such as contamination by nitrate fertilizers, forage, and agricultural drinking water and addition of nitrate to the cheese milk. It is suggested that stricter control of nitrate in cheese is necessary, and that it should not be used to mask poor hygienic conditions during manufacturing. Hygienic condition must be kept at excellent level in related industries.

Listeria spp. in the raw milk and dairy products in Antakya, Turkey

In this study, the presence of Listeria spp. was investigated in a total of 157 raw milk and dairy product samples sold in Antakya (Antioch). The prevalence of Listeria spp. in raw milk and Turkish white cheese samples was found to be 2.12% and 8.23%, respectively. Listeria monocytogenes was not isolated from raw milk and found in only two cheese samples (2.35%). No Listeria spp. were isolated in any of the butter and yoghurt samples.

Determination of microbiological contamination sources during Turkish white cheese production

This study has been conducted to determine the microbiological contamination sources during production of white cheese in a local dairy plant, Bursa, Turkey. Twenty nine different control points or sample types (raw milk, pasteurized milk, milk in cheese vat, curd, moulded cheese before salting, moulded cheese after salting, cheese at cold holding and vacuum packaged cheese; samples from starter culture, rennet, calcium chloride solution, brine, cheese vat, cheese cloth, polyethylene separator sheet, milk stirrer, curd cutting knife, side pressure plate, upper pressure plate, moulded cheese cutting knife, cheese tray, packaging material used during production; workers’ hands, cold room and production room air, floor, wall, and potable water) have been examined for the enumeration of total aerobic mesophilic bacteria, staphylococci, coagulase positive staphylococci, Enterobacteriaceae, enterococci, coliforms, Escherichia coli, psychrophilic bacteria, and yeast and molds. We determined: starter culture as the possible contamination source of coagulase positive staphylococci, enterococci and psychrophilic bacteria; brine and upper pressure plate as the contamination source for staphylococci; floor and packaging material as the contamination source of psychrophilic bacteria; cheese vat, cheese cloth and curd cutting knife as the contamination source of total aerobic mesophilic bacteria; cold room and production room air as the contamination sources for yeast and molds.

Changes in the microbiological and chemical characteristics of an artisanal Turkish white cheese during ripening

Changes in the physico-chemical and microbiological properties of artisanal Turkish White cheese were studied throughout 105 days of ripening. Total solid, fat in solid, titratable acidity, pH, salt in total solid, total nitrogen, water-soluble nitrogen, ripening index, amino acids and biogenic amines were determined. Also, the counts of lactic acid bacteria, yeast, moulds and coliforms were done. Biogenic amines in cheeses were tyramine, histamine and phenyletylamine while tryptamine was the only detected at the beginning of maturation at the low concentration. Tyramine content increased during ripening reaching, 12.36 mg/kg at 75 days. A significant correlation could not be found ( P > 0.05 ) between microorganisms and biogenic amines. Data points represent averages of three experiments.

The effect of selenium and zinc fortification on the quality of Turkish white cheese

Fortification of Turkish white cheese with selenium and zinc was tested using two different methods: fortification of cheese milk and fortification of brine solution, in which the cheeses were ripened. The recoveries of Se and Zn in cheese curd and the chemical and sensory characteristics of cheese samples were measured. The fortification method affected the composition (total solids, protein, fat and salt) of the experimental cheeses significantly (P < 0.05). The recovery of zinc was a maximum in the method in which the fortifying agents were added into the cheese milk, and corresponded to 87.55%. Selenium recovery was a maximum in the method in which the fortifying agents were added into the brine solution, and corresponded to 70.91%.

Relationships between proteolytic and lipolytic activity and sensory properties (taste–odour) of traditional Turkish white cheese

Protein and lipid changes and their effects on the sensory properties (taste–odour) of Turkish white cheese were studied. Mean values for the chemical properties of white cheese were: total solids (TS) 44.39 g/100 g; titratable acidity 2.15% (as lactic acid); pH value 4.50; fat‐in‐dry matter 47.80 g/100 g; salt‐in‐dry matter 8.65 g/100 g; total nitrogen (TN) 2.50 g/100 g; water‐soluble nitrogen (WSN) 0.48 g/100 g; ripening index (RI) 18.98%; tyrosine 65.00 mg/100 g; acid degree value (ADV) 385.96 mg KOH/100 g fat; volatile fatty acids (VFA) 15.54 mL 0.1 N NaOH/100 g and total free fatty acids (TFFA) 1325.96 mg/100 g cheese. Sensory scores for taste and odour were 23.67 (out of 35) and 8.28 (out of 10), respectively. The chemical qualities of the cheeses, including acidity, dry matter, fat‐in‐dry matter and VFA had an effect on flavour (P &lt; 0.05).

Probiotic white cheese with Lactobacillus acidophilus

The objective of the present study was to determine the effects of Lactobacillus acidophilus on the sensory attributes, ripening time, and composition of Turkish white cheese and to investigate the survival of L. acidophilus during ripening of the cheese stored in vacuum or in brine. Two types of white cheeses, traditional cheese (control, made with Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris ) and probiotic cheese (made with Lactococcus lactis ssp. lactis , Lactococcus lactis ssp. cremoris and L. acidophilus 593 N), were produced and ripened in vacuum pack or in brine at 4°C for 90 days. Cheese samples were assessed for microbiological and compositional properties, proteolysis, and sensory evaluation at different ripening stages. On ripening in vacuum pack, L. acidophilus survived to numbers >10 7 cfu g −1 , which is necessary for positive effects on health. Protein, dry matter, salt content, and percentage of lactic acid in the vacuum-packed and brine-salted probiotic cheeses were significantly different. Also, the lactic acid content of probiotic cheeses was slightly higher than that of the controls for both vacuum- and brine-packed cheeses. Vacuum-packed probiotic cheese had the highest levels of proteolysis and the highest sensory scores of all cheeses. Consequently, L. acidophilus could be used for the manufacturing of probiotic white cheese to shorten ripening time and vacuum packaging is the preferred storage format.

Antibiotic resistance and incidence of Enterococcus species in Turkish white cheese

Thirty samples of Turkish white cheese were analysed for the presence of Enterococcus spp., and presumptive isolates were identified by morphological, cultural and biochemical tests and confirmed by the API 20 Strep System. Among the 101 isolates of Enterococcus spp., 62 were E. faecalis, 25 were E. faecium, seven were E. durans, five were E. mundtii and two were E. hirae/dispar. The resistance of the isolates to 13 different antibiotics was determined by the Kirby–Bauer disc diffusion test. Resistance to streptomycin, erythromycin, oxacillin and vancomycin was frequently found in these enterococci, and resistance to vancomycin was found in 96.8% of E. faecalis isolates and 76%E. faecium. The most effective antimicrobials were ampicillin (69.3% of isolates inhibited) and imipenem (76.3% of isolates inhibited). This examination confirmed the presence of enterococci, especially vancomycin‐resistant strains, in Turkish white cheese, indicating poor sanitary conditions during production and processing and a significant health risk for consumers.

The effects of some starter cultures on the properties of Turkish White cheese

White cheese samples were manufactured from bovine milk using three different commercial direct vat starter cultures (DVS‐1, ‐2 and ‐3) and a lyophilized culture, and ripened at 4 ± 1°C for 90 days. The composition, titratable acidity and ripening indices of the cheese samples were determined on the 2nd, 30th, 60th and 90th days of ripening. The ratios of total solids, protein and fat were higher for cheeses manufactured using DVS‐2 and lyophilized cultures but the titratable acidity in cheese produced using DVS‐3 and lyophilized cultures was higher (P &lt; 0.01). The mean value of the ripening indices of the cheese produced using the lyophilized culture was lower than the cheeses produced with added DVS cultures (P &lt; 0.05). The total solids, ash, salt ratios, titratable acidity and ripening indices values increased for all types of white cheeses during ripening (P &lt; 0.05).

Changes in the sensory, microbiological and compositional properties of Turkish white cheese during ripening

Results of the chemical, microbiological and sensorial properties of Turkish white cheese samples are presented during ripening period. It was observed that dry matter, fat, sodium chloride, ash and acidity increased during ripening, whereas pH value decreased. Dry matter, fat in dry matter, salt in dry matter, ash in dry matter and acidity (lactic acid) contents of cheese samples were found between 35.41-39.48%, 42.54-46.10%, 10.80-11.46%, 12.33-13.49%, and 0.61-1.11%, respectively. The pH values were found between 4.98-5.68. Also, high counts of total mesophilic bacteria and Lactobacilli were recorded throughout the ripening of the cheese. Low pH levels and high NaCl content after 30 days affected the growth of most microbial groups resulting in considerably lower counts at 3 months. Lactobacilli constituted the dominant microflora of the cheese. According to sensory evaluations, the cheese samples were more preferred with aging. This study reported here describes chemical, microbiological and organolep...