White Cheese Samples Research Articles

Simultaneous Study of the Combined Effect of Gliding Arc Plasma and Zataria multiflora Essential Oil on Pathogens Inactivation and Quality Changes in Sliced Iranian White Cheese.

This study aimed to inactivate Escherichia coli O 111 , Listeria monocytogenes, and Aspergillus flavus on sliced Iranian white cheese by using the combination of gliding arc nonthermal plasma (GAP) and Zataria multiflora essential oil (ZEO). The cheese samples were exposed to different levels of GAP (0, 2, and 5 min) and ZEO (0 and 100 ppm) and stored at 4°C for 60 days. The extraction yield of ZEO based on dry weight was 1.66%. Carvacrol (33.85%) was the most important compound in ZEO. During the storage period, E. coli and L. monocytogenes counts increased in all samples. However, the most effective inhibition of E. coli and L. monocytogenes was observed in samples treated with 100 ppm ZEO combined with 2 min of GAP, and 100 ppm ZEO combined with 5 min of GAP, respectively, resulting in increases of only 1.35 and 1.8 log CFU/g over the storage period. In terms of the growth inhibition percentage of A. flavus, the lowest inhibition was detected in the presence of essential oil alone, while the highest inhibitory effect resulted from 5 min of plasma treatment combined with essential oil. GAP treatment also reduced the pH value of the cheese while increasing thiobarbituric acid reactive substances (TBARS). The control sample showed the lowest pH and the highest TBARS during storage. The highest overall acceptance sensory properties score was observed in cheese samples treated with 2 min of GAP and 100 ppm ZEO. According to the results of microbial, chemical, and sensory tests, Iranian white cheese samples treated with 2 min of GAP and 100 ppm ZEO can be used as a novel technique for sterilization and extending the shelf life of white cheese.

Presence of Staphylococcus aureus in White Cheese: Determination of Enterotoxin and Antimicrobial Resistance Genes

This study aimed to evaluate Staphylococcus aureus contamination, enterotoxin presence, and antibiotic resistance in 100 white cheese samples, both packaged and unpackaged. Polymerase Chain Reaction (PCR) analysis showed S. aureus in 16 (32%) of the 50 unpackaged samples and 8 (16%) of the 50 packaged samples. 46 S. aureus isolates were obtained from 24 S. aureus positive samples. Moreover, the sed gene, associated with enterotoxin production, was detected in two 46 isolates, one from packaged and one from unpackaged white cheese samples. The isolates exhibited resistance to erythromycin (6.52%), gentamicin (10.87%), chloramphenicol (6.52%), trimethoprim-sulfamethoxazole (2.37%), rifampicin (15.21%), tetracycline (28.26%), cefoxitin (43.47%), and penicillin G (34.78%). Oxacillin and vancomycin resistance among the 46 S. aureus isolates was examined using the minimal inhibition concentration (MIC) method. According to the MIC results, none of the isolates were resistant to oxacillin. However, 47.82% of the isolates were resistant to vancomycin. Overall, the isolates exhibited resistance to 9 out of the 10 antibiotics tested. In addition to the resistance profiles, resistance genes were also investigated. It was found that 3 out of the 46 S. aureus isolates (13.6%) carried the mecA gene, 6 (27.2%) carried the mecC gene, and 1 (2.17%) carried both mecA and mecC genes. In conclusion, detecting S. aureus in white cheese indicates poor hygiene. The high antibiotic resistance, presence of resistance genes, and enterotoxin genes in some isolates suggest poses a risk of transmitting resistant microorganisms to humans, potentially complicating disease treatment and causing foodborne illness, posing a public health concern now and in the future.

Determination of bacteriocin genes and antimicrobial activity of Lactiplantibacillus plantarum isolated from feta cheese samples.

In this study designed to isolate lactic acid bacteria (LAB) with bacteriocin production potential, white cheese samples were collected from different provinces of Turkey and isolation was carried out. A series of experiments were carried out for the main purpose and the actual bacteriocin producers were identified by detecting the genes encoding this bacteriocin. The experiments carried out in this direction were initially carried out with 20 isolates and as a result of various experiments, the number of isolates was reduced to 8 and the study was continued with 8 isolates. In order to determine that the eight isolates identified as a result of a phenotypic and biochemical characterization study were true bacteriocin-producing strains, their antibacterial activity was investigated and then the presence of bacteriocin genes was examined by specific polymerase chain reaction (PCR) using gene-specific primers. As a result, MS16 coded Lactiplantibacillus plantarum OR922652 was found to have strong antibacterial activity against Escherichia coli, Klebsiella pneumonia, Yersinia enterocolitica, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus; the isolate was susceptible to clinically important antibiotics (ciprofloxacin, gentamicin, penicillin G, ampicillin, chloramphenicol, and vancomycin) and resistant to erythromycin, had no hemolytic activity and possessed plnA and plnD genes encoding bacteriocin production. In conclusion, the MS16 coded L. plantarum isolate has emerged as a promising strain that can be used especially in the health field and in the food industry related to LAB.

Antimicrobial Effect of Cuminum Cyminum Essential Oil in Iranian White Cheese by Different Packaging

Background: As one of the most crucial food categories, nutritionists commonly recommend dairy products. Since these products are highly perishable, it is important to find a method to increase their shelf life and conserve their freshness for a long time. Objectives: The present study aims to assess the antibacterial properties of Cuminum cyminum essential oil (CCE) on the quality of refrigerated white cheese preserved through packing under gas mixtures (air, modified atmosphere packaged [MAP]: 70% O2–30% CO2). Methods: The mesophilic bacteria (TMC), psychrotrophic bacteria (PTC), lactic acid bacteria (LAB), Enterobacteriaceae, Listeria monocytogenes and mold and yeast counts were determined using PCA, DCRB, PCA, MRS agar, violet red bile agar and PALCAM agar, respectively, during 35 days of storage period. Results: The results revealed that the growth rate of TMC and LAB, Enterobacteriaceae, mold and yeast, PTC and L. monocytogenes considerably decreased in white cheese samples due to the integration of CCE and MAP. The lowest number was observed in a case with samples packed in MAP+ 0.06% CCE after 35 days of storage. Conclusion: Given the microbial characterization improvements, CCE was determined to be an optimal alternative, along with MAP, for applications in white cheese.

Effect of Different Heat-Treated Ultrafiltration (UF) Retentates with Altered Protein-to-Fat Ratios on Physicochemical and Sensory Properties of UF White Cheese

In this study, ultrafiltration (UF) white cheese samples were manufactured using UF retentate, which had been heat-treated at different temperatures (75°C and 85°C for 15 s) and had altered ratios of protein-to-fat (P/F) (0.8, 0.7, and 0.6). The physicochemical and sensory properties of UF white cheeses during storage (90 days) were determined. White cheese manufactured from UF retentate with a P/F ratio of 0.6 had higher fat and lower protein contents than those with the P/F ratios of 0.7 and 0.8. Treatment temperature significantly influenced the pH and titratable acidity values of UF white cheeses. The highest hardness and chewiness values and the lowest adhesiveness values were determined in UF white cheese with P/F ratios of 0.8 and heat-treated at 85°C. During storage, the L*, a*, b*, and ΔE* values of white cheeses varied between 94.51 and 98.34, -0.77 and -0.06, 7.78 and 10.13, and 10.61 and 13.00, respectively. The use of high-fat-content ultrafiltered retentate subjected to high temperatures in the manufacture of white cheeses had a positive effect on overall acceptability scores.

Investigation of Staphylococcus spp. and Coliform Bacteria Contamination Sources after Cleaning-in-Place in Production Lines of Dairy Factories in Türkiye.

Microorganisms detected on dairy factory surfaces after disinfection can cause product contamination, leading to economic losses and health hazards for consumers. In this study, the presence of Staphylococcus spp. and Coliform in a total of 450 samples taken from food-contact and non-contact surfaces (stainless steel, plastic, cloth, and tiles surfaces), raw milk and final product (white cheese, kashar cheese, butter, yogurt, and cream) samples in five dairy factories was investigated by conventional techniques. The isolates obtained were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. In this study, a total of 54 Staphylococci (16.7% S. aureus and 81.5% coagulase-negative Staphylococci [CNS]) and 44 coliform isolates were identified at the species level. The most common CNS isolated by samples was S. epidermidis followed by S. saprophyticus, S. capitis, S. succinus S. carnosus. S. xylosus, S. sciuri, S. equorum, S. warneri, and S. hominis. Eighteen of the coliform isolates (41%) were identified as E. coli; 13 (29.5%) as E. cloacae; 3 (6.9%) as E. kobei, C. freundii, and K. oxytoca; 2 (4.5%) as K. pneumoniae; 1 (2.3%) as E. ludwigii and C. farmeri. The contamination rate of non-food contact surfaces (71.3%) was found to be higher than food contact surfaces (10.4%), and contaminated surfaces were found to be effective in product contamination. Study results show that some bacterial species obtained from raw milk, surfaces, and final products are factory specific and surface-associated bacteria are prominent in the product microbial profile.

Psychrotrophic Bacteria and Yeast Populations in Turkish White and Tulum Cheeses

In this study, pH and microbiological (psychrotrophic bacteria and yeast) properties of White and Tulum cheeses were investigated. According to the results of our study, the lowest pH value identified was 4.42, and the highest pH was 5.84 in the cheese samples. Psychrotrophic bacteria counts ranged from 4.15 to 6.21 log CFU/g for White cheese and 4.02 to 6.15 log CFU/g for Tulum cheese. Psychrotrophic yeast counts ranged from 2.98 to 7.58 log CFU/g for White cheese and 2.99 to 6.77 log CFU/g for Tulum cheese. The highest values of psychrotrophic yeast were detected in the Tulum cheese samples. As a result, it was determined that the numbers of psychrotrophic bacteria and yeast were high in both Tulum and White cheese samples. These high numbers of psychrotrophic microorganisms during cheese storage in the refrigerator may increase even further and reduce shelf life. To extend the shelf life of these cheeses, it is recommended to ensure hygienic handling practices and explore the use of natural preservatives or modified atmosphere packaging.

Utilisation of Lactococcus lactis subsp. lactis (PY91K) and Lactiplantibacillus plantarum (Y48) to control Clostridium sporogenes during Turkish white cheese production and storage

Abstract This study investigated the inhibition of Clostridium species, isolated from cheeses with late-blowing defects, by lactic acid bacteria (LAB). Four batches of Turkish white cheeses were produced; control cheese, cheese sample containing Lactococcus lactis subsp. lactis (PY91K) and Lactiplantibacillus plantarum (Y48) as protective cultures (LAB), a cheese sample containing the protective culture and inoculated with Clostridium sporogenes spores (CL-LAB) and finally a cheese sample containing only Cl. sporogenes spores (CL). White cheese's microbiological and physicochemical properties were also determined throughout the 90-day storage period at 4 °C. Approximately 1 log reduction in Cl. sporogenes (ZMP-1-4) spores was observed in the LAB co-inoculated Turkish white cheese samples.

Determination of Thermotolerant Yeast Population in Dairy Products

Thermotolerant yeasts constitute a critical indicator for the effective management of product quality, food safety, and production processes in the dairy industry. This study aims to investigate the presence of thermotolerant yeasts in diverse dairy products within the context of Turkiye. In this study, pH and thermotolerant yeast properties of Turkish white cheese, butter, cream (Kaymak), and Tulum cheese were investigated. Thermotolerant yeast counts in butter samples ranged between 4.30 and 4.82 log CFU/g, with pH values ranging from 4.91 to 6.68. Thermotolerant yeast counts of Tulum cheese, white cheese and cream samples were <2 log CFU/g. The pH values of cream and Tulum cheese were ranged from pH 5.07-6.79 and pH 4.91-6.68, respectively. The mean pH value for white cheeses was 4.98. As a results, thermotolerant yeast counts of Tulum cheese, white cheese and cream samples were below the detectable value; however, a high number of thermotolerant yeasts were determined in butter samples. In conclusions, these findings offer valuable insights for evaluating the microbiological quality of different dairy products, aiding producers in enhancing safety and quality for consumers.

Impact of low-dose gamma irradiation treatment on microbial and chemical properties of raw milk white cheese

Using raw milk in cheese-making has microbiological risks, however a considerable number of artisan cheese makers around the world prefer raw milk, as heat treatment damages natural microbiota and alters the characteristic taste and flavor of the cheese. The potential of the gamma irradiation process to make the raw milk cheese microbiologically safe was investigated in this study. A total of 5 groups of cheese were produced, including control groups (control pasteurized milk cheese and control non-irradiated raw milk cheese). After the white cheese samples were kept in brine for 1 night, they were vacuum-packaged and each group was subjected to gamma irradiation at doses of 1, 2, and 3 kGy, respectively. Chemical composition, pH, acidity, Urea-PAGE images, total aerobic mesophilic bacteria (TAMB), coliform group bacteria, E. coli, yeasts and molds, Lactobacillus and Lactococcus counts of cheese samples were determined during 60 days of storage at 4°C. All analyzes were performed on days 1, 30, and 60 of production. We found that irradiation reduced the microbiological load of the cheeses and slowed down the degradation of αs1-CN and β-CN especially at 3 kGy. Irradiation at 3 kGy successfully inhibited the coliforms and E. coli, however yeast and mold counts were still high due to initial high levels. Our study showed that irradiation of the raw milk cheese is a promising method to reduce the microbial counts to acceptable limits which could reduce the required ripening periods for the microbial safety of raw milk cheeses.

Fresh White Cheeses from Buttermilk with Polymerized Whey Protein: Texture, Color, Gloss, Cheese Yield, and Peptonization

Buttermilk and whey, despite their documented health and technological potential, are still not sufficiently utilized for the development of new products. In this research, the texture, color, gloss, cheese yield, and peptonization of fresh white cheeses made from buttermilk with the addition of whey proteins after heat treatment were analyzed. Additionally, the influence of the polymerization process on cheese yield and composition was examined. Four fresh white cheese samples were prepared: without a whey protein concentrate (FWC); with a whey protein concentrate (FWC/WPC); with single-heated polymerized whey proteins (FWC/SPWP); and with double-heated polymerized whey proteins (FWC/DPWP). The introduction of whey proteins in buttermilk cheese production increased the cheese yield by over 2-fold. There were no differences in color and gloss between the FWC/SPWP and FWC/DPWP samples. The cheese became glassy and transparent during melting. The content of uncrushed curd that remained white ranged from 27% in FWC/DPWP to 74% in FWC/SPWP.

Bioactive potential of ripened white cheeses manufactured in different geographical regions of Turkey.

This study investigated the potential bioactive properties of white cheeses produced in different regions of Turkey, including their potential antioxidant, antihypertensive, antidiabetic, antimicrobial, and anticancer activities. The cheese samples were analyzed both before and after in vitro digestion. The study found that all cheese samples exhibited significant angiotensin-converting enzyme inhibition activity both before (45.5%-70.1% for 0.03gcheese/mL) and after in vitro digestion (25.5%-63.5% for 0.0167g cheese/mL), whereas α-amylase inhibition activity was present in all samples (in the range of 5.1%-50.0% for 3.0×10-5 gcheese/mL) but disappeared after digestion, and α-glucosidase inhibition activity was only detected after in vitro digestion (from 20.5% to 60.4% for 5.6×10-5 gcheese/mL), indicating potential antidiabetic properties. However, antimicrobial and anticancer activities were not observed in any of the samples. The results also suggest that the bioactivity potential of white cheese may vary depending on the region of production, as cheeses from the Marmara region exhibited high α-glucosidase inhibition activity after digestion. In conclusion, while white cheese is a valuable addition to the diet due to its high nutritional value and potential health benefits. This study revealed the bioactive potential of ripened white cheese and in vivo investigations of the cheese components would better show their possible benefits. PRACTICAL APPLICATION: Although the bioactivity potentials varied among the ripened white cheese samples produced in different regions of Turkey, a consistent trend was observed in terms of their presence or absence. Our research revealed that all ripened cheese samples demonstrated significant potential antioxidant and antihypertensive activities, as well as potential antidiabetic properties. Moreover, it can be interpreted that ripened white cheese has the potential to reduce the digestion of carbohydrates when consumed with carbohydrate-rich foods. Although the present results provide limited practical findings directly applicable to the industry, if the data and information obtained from this study are further explored and further studies delving into specific mechanisms of bioactive components could emerge.

The characterization of the non-starter lactic acid bacteria and yeast microbiota and the chemical and aromatic properties of traditionally produced Turkish White Cheese.

Turkish White Cheese is a brined (or pickled) cheese with a salty, acidic flavor and a soft or semi-hard texture. It is the most produced and consumed type of cheese in Turkey. The purpose of this study was to determine the non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese and analyze the chemical properties and the aroma profile of the cheese. The results of the study identified 27 distinct strains belonging to 14 the non-starter lactic acid bacteria species and 49 different strains belonging to 11 yeast species. Lactobacillus plantarum was found to be the dominant species among the lactic acid bacteria, while Candida zeylanoides was the dominant yeast species in the White Cheese samples. In addition, Kluyveromyces lactis and Debaryomyces hansenii were prominent yeast species in cheese samples. Turkish White Cheese samples had different aromatic properties. The study is highly significant as it anaylzed both non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese through molecular methods. It also determined and analyzed a number of chemical and aromatic properties of White Cheese.

Incidence of <em/Salmonella</em> in Traditional White Cheese in Gaza markets, Palestine

Introduction: Salmonella has gained more interest because it cause food borne illnesses. Traditional soft cheese made from unpasteurized milk may contain salmonella. Methods: A descriptive study was performed, one hundred and four samples of fresh white cheese collected from street venders and the local markets to investigate the incidence of salmonella in fresh white cheese in Gaza. Results: Salmonella was found in four samples of "Traditional cheese". Differences between percentages of samples were not statistically significant. Conclusion: traditional cheese highly contaminated and usually exceeded the Palestinian Standard. The detection of Salmonella spp. suggests that traditional soft cheese commercialized in Gaza may represent a health risk for the consumers.

Monitoring Turkish white cheese ripening by portable FT-IR spectroscopy

The biochemical metabolism during cheese ripening plays an active role in producing amino acids, organic acids, and fatty acids. Our objective was to evaluate the unique fingerprint-like infrared spectra of the soluble fractions in different solvents (water-based, methanol, and ethanol) of Turkish white cheese for rapid monitoring of cheese composition during ripening. Turkish white cheese samples were produced in a pilot plant scale using a mesophilic culture (Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris), ripened for 100 days and samples were collected at 20-day intervals for analysis. Three extraction solvents (water, methanol, and ethanol) were selected to obtain soluble cheese fractions. Reference methods included gas chromatography (amino acids and fatty acid profiles), and liquid chromatography (organic acids) were used to obtain the reference results. FT-IR spectra were correlated with chromatographic data using pattern recognition analysis to develop regression and classification predictive models. All models showed a good fit (RPre ≥ 0.91) for predicting the target compounds during cheese ripening. Individual free fatty acids were predicted better in ethanol extracts (0.99 ≥ RPre ≥ 0.93, 1.95 ≥ SEP ≥ 0.38), while organic acids (0.98 ≥ RPre ≥ 0.97, 10.51 ≥ SEP ≥ 0.57) and total free amino acids (RPre = 0.99, SEP = 0.0037) were predicted better by using water-based extracts. Moreover, cheese compounds extracted with methanol provided the best SIMCA classification results in discriminating the different stages of cheese ripening. By using a simple methanolic extraction and collecting spectra with a portable FT-IR device provided a fast, simple, and cost-effective technique to monitor the ripening of white cheese and predict the levels of key compounds that play an important role in the biochemical metabolism of Turkish white cheese.

Molecular genotyping of Salmonella spp. isolated from cheese samples of local stores in Al-Diwaniyah city, Iraq.

Food safety is an important subject that the global cheese industry increases awareness of. This urges these economic sectors to elevate the level of research to minimize cheese contamination with pathogenic bacteria, such as Salmonella. Based on these merits, this study was conducted to genotype Salmonella spp. isolated from cheese samples of local stores in Al-Diwaniyah City, Iraq. The study used 41 samples of local fresh unsalted white cheese in a selective-growth-based isolation of Salmonella. These isolates were confirmed utilizing a slide-agglutination (SA) test and VITEK® 2 system (V2S). Then, the isolates were subjected to conventional PCR and sequencing techniques that both targeted the 16S rRNA gene. For subtyping, the Salmonella isolates were subjected to a random amplified polymorphic DNA (RAPD)-PCR method. The results of both SA and V2S revealed the presence of 14 (34.2%) isolates of Salmonella spp. in the cheese samples. The PCR confirmed 6 (42.9%) of these isolates, which further were defined with close nucleotide similarity (98.03%) and (97.88%) to different world isolates, such as Salmonella enterica subsp. Arizonae and Salmonella enterica subsp. enterica serovar Typhi, respectively. The RAPD-PCR findings showed different fragments for all the tested isolates. The present study indicates that the samples of the local fresh unsalted white cheese contain different Salmonella genotypes, which could be originated from different contamination sources.

Antimicrobial Edible Cellulose-Based (CB) Films and Coatings for Enhancing Microbial Safety of White Cheese During Storage

In this research, the antioxidant and antibacterial characteristics of edible cellulose-based film (CBEF) coating incorporated with β-carotene, Hesperedin and Propolis on the quality of the white cheese at 4°C were investigated. Samples evaluated were: Control, CBE films with 8 different contents containing natural or non-natural antimicrobial agents for 15 days at 5 day intervals. The antimicrobial effects of edible cellulosic films prepared with antimicrobial agents against Staphylococcus aureus and Escherichia coli, which are important food pathogens, were directly evaluated with artificially contaminated food samples under cold storage conditions. Fresh white cheese samples, which are one of the semi-hard traditional Turkish cheeses, were used for artificial contamination. The antimicrobial activity of the tested antimicrobial substances was measured by the paper disc method. The DPPH free radical scavenging activities, the total phenolic content, and the characteristics (FT-IR, DSC and TGA) of the CBEFs were investigated. All of the samples significantly reduced E. coli, S. aureus and total viable counts, as compared with control during the storage time. Specifically, it was determined that hesperidin sprayed films showed an antimicrobial effect on E.coli growth and carotene sprayed films showed an antimicrobial effect on S. aureus growth. Growth of both bacterial species was highly inhibited (>50%) in the presence of 20% propolis. It was concluded that β-carotene, hesperidin and propolis can be substituted as natural preservatives in white cheese. With this advanced packaging technology, food safety can be ensured, the shelf life of the product can be extended and food losses in this sector can be reduced.

Identification and Potential Biotechnological Characterization of Lactic Acid Bacteria Isolated from White Cheese Samples

In this study, the isolation of lactic acid bacteria was carried out from one hundred white cheese samples collected from different regions of Turkey. Subsequently, phenotypic and genotypic characterization of the isolates was performed. Biochemical characteristics of the isolates were determined by API 50CHL. Furthermore, the biotechnological enzyme production potential of the isolates was screened. Genomic fingerprint profiles of the test isolates were detected by using rep-PCR (BOX-PCR), which has been used successfully in the differentiation of microorganisms at the species, subspecies, and even strain levels. The results showed that a total of forty-one bacteria were isolated and seventeen of which are found to be different species. The isolates generally grew at 4-6 pH values, 0-8% NaCl and 30-40°C. Later, isolates thought to be different species were identified by 16S rRNA gene sequence analyses. According to 16S rRNA sequence results, MA56 showed a 96.41% similarity match to Lentilactobacillus buchneri, it is thought to be a new species. In addition, MA19, MA25, MA43, and MA47 were determined to have multi-enzyme production potential. MA43 has a plantaricin gene and it showed a high antagonistic effect on Escherichia coli O157:H7 ATCC 43888 and Pseudomonas aeruginosa ATCC 9027. Inhibition zones were measured at 19 mm and 16 mm respectively.

Identification of E.coli. In Sudanese White Soft Cheese

Study of dairy products is of great interest to the daily consumer . This research studied the total count of bacteria and the identification of the Escherichia coli (E.coli) bacteria of ready for sale and consumption white cheese.Three samples of locally produced cheese were collected from market in Khartoum at different dates and stored in polypropylene (PP) packaging at temperature of 4oC. The different samples were then subjected to laboratory tests to determine the total bacterial colonies and hence the total count of bacteria and E.coli in white cheese.The quality of white cheese including chemical and microbial characteristics which are affected by several factors were studied. The average bacterial colonies for cheese showed differences at two different dilutions (10-4and 10-5) of the Agar medium used. The average numbers of the bacterial colonies for the three samples were 15.54, 11.74 and 9.79. The biochemical reaction of the isolated bacteria from the three samples of white cheese showed no E.coli presence, gram negative bacteria, however, was found to be present.

Beyaz Peynir Yağ Asidi Profilinin FTIR Spektrometresi ile İzlenmesinde Basit Ekstraksiyon Yönteminin Ölçüm Performansına Etkisi

During cheese ripening many biochemical reactions occur, including hydrolysis of fat, lactose metabolism, and protein breakdown. The aim of this study is to compare the direct measurement method from cheese with simple extraction methods in determining the hydrolysis of fats by FTIR spectroscopy. For this purpose, white cheese samples were produced, ripened for 60 days and analysed at 20-day intervals. The content of fatty acids was determined by gas chromatography, while its estimation was performed using Partial Least Squares Regression (PLSR). As a result, the PLSR performance obtained from fat extract samples by FTIR spectroscopy was shown higher values than the performance obtained from the direct measurement from cheese. It has been shown that simple extraction methods provide higher performance in FTIR spectroscopic measurements made from cheese.