Kasar Cheese Research Articles

Inhibitory Effect of Sodium Alginate Nanoemulsion Coating Containing Myrtle Essential Oil (Myrtus communis L.) on Listeria monocytogenes in Kasar Cheese.

The present study aimed to characterize the physical properties of nanoemulsion-based sodium alginate edible coatings containing myrtle (Myrtus communis L.) essential oil and to determine its inhibitory effects on Listeria monocytogenes in fresh Kasar cheese during the 24-day storage at 4 °C. The GC-MS analysis showed that the main components of myrtle essential oil were 1,8-cineol (38.64%), α-pinene (30.19%), d-limonene (7.51%), and α-ocimene (6.57%). Myrtle essential oil showed an inhibitory effect on all tested L. monocytogenes strains and this effect significantly increased after ultrasonication. Minimum inhibitory and minimum bactericidal concentrations of myrtle essential oil nanoemulsion were found to be 4.00-4.67 mg/mL and 5.00-7.33 mg/mL, respectively. The antibacterial activity of myrtle essential oil nanoemulsion against L. monocytogenes was confirmed by the membrane integrity and FESEM analyses. Nanoemulsion coatings containing myrtle essential oil showed antibacterial activity against L. monocytogenes with no adverse effects on the physicochemical properties of cheese samples. Nanoemulsion coatings containing 1.0% and 2.0% myrtle essential oil reduced the L. monocytogenes population in cheese during the storage by 0.42 and 0.88 log cfu/g, respectively. These results revealed that nanoemulsion-based alginate edible coatings containing myrtle essential oil have the potential to be used as a natural food preservative.

Effect of whey protein edible films containing plant essential oils on microbial inactivation of sliced Kasar cheese

The study aimed to reduce microbial contamination of sliced Kasar cheese. Oregano oil (OEO), garlic oil (GEO), nisin (NIS), and natamycin (NAT) containing whey protein isolate (WPI) films were used as layers onto Kasar cheese slices inoculated with Escherichia coli 0157:H7, Salmonella Enteritidis, Listeria monocytogenes, Staphylococcus aureus, and Penicillium spp. The microbial inactivation was determined during 15 days of storage. Kasar cheese inoculated with E. coli 0157:H7 layered with WPI-OEO film showed 1.48 log reduction, whereas the same film reduced S. aureus counts by 2.15 log when compared to control samples after 24 h. WPI films containing essential oils or NIS showed similar microbial inactivation pattern for S. Enteritidis. NIS containing WPI film had the highest microbial inactivation against L. monocytogenes, while NAT containing WPI films had the highest reduction against Penicillium spp. Application of WPI films containing plant essential oils on sliced Kasar cheese provided significant microbial reductions during storage.

Microbial species playing roles for the production of traditional Kasar cheese during pre-maturation period

The microbial flora of traditional Kaşar cheese samples obtained from six dairy plants during pre-maturation period of Kaşar maturation was analysed. In total, 500 isolates of none-starter lactic acid bacteria (NSLAB) and 80 fungi isolates were isolated, and they were subjected to molecular discrimination by RAPD-PCR and rep-PCR analysis. Genotypic characterization of these isolates revealed the presence of 45 distinct strains belonging to 13 different NSLAB species with Lactobacillus paracasei as the dominant species. A rich yeast microflora in Kaşar samples was also observed with the presence of 19 distinct strains belonging to 8 different species with Pichia kudriavzevii as the dominant species. During this period, only two Penicillium species were found in Kaşar samples. This study confirmed the biodiversity of NSLAB and fungi microflora of Kaşar cheese during pre-maturation period, and these results are important for the development of starter cultures for Kaşar production at industrial level.

Evaluation of Some Physical, Chemical and Sensory Properties of Kasar Cheese and Its Processed and Analogue Types

The objective of this study was to evaluate the changes in physical, chemical and sensory properties of the kasar cheese and its processed and analogue types during 90-day storage. Aroma-active compounds in the cheeses were identified by gas chromatography-olfactometry. Sensory properties of the cheeses were determined by descriptive sensory analysis. Differences in basic composition of the cheeses were found. There were also significant differences among the cheeses in terms of meltability, oil separation index, L* and a* values. Whey, cooked, creamy and fermented were the most intense sensory descriptors in the cheeses analyzed on days 1 and 30. However, waxy and animal intensities were much higher in analogue cheese than others. 18 aroma-active compounds were determined in the cheeses during 90 day storage. Diacetyl, acetic acid, butyric acid, 2-/3-methyl butyric acid, 2-acetyl-2-thiazoline, b-ionene, 2-phenylethyl alcohol, maltol, p-cresol, sotolon, d-decalactone and g-dodecalactone were some of the characteristic aroma-active compounds. Kasar cheese was the most liked cheese while analogue cheese was the least liked cheese by consumers.

English

Lactic acid bacteria (LAB) arise in KaAŸar cheese, an artisanal pasta filata cheese produced in Turkey from raw milk without starter addition or pasteurized milk with starter culture. In this study, 13 samples of KaAŸar cheese that were produced from raw milk were used as reference materials. LAB were characterized by using phenotypic, API and Fourier transform infrared (FTIR) spectroscopy methods. One hundred and fifty-seven (157) strains were isolated from 13 cheese samples, and identification test was performed for 83 strains. At the end of the study, a total of 22 Lactococcus sp., 36 Enterecoccus sp. and 25 Lactobacillus sp. were determined in the isolated strains by phenotypic identification. After identification with FTIR spectroscopy and statistical analysis, expected results were not taken by FTIR spectroscopy due to higher correlation (> % 99) obtained with more than one reference culture. Fewer number of reference strains was a limitation of the analysis. Therefore, identification should be made with more reference bacteria in the FTIR analysis and should also be supported with molecular techniques. Key words: KaAŸar cheese, lactic acid bacteria, identification, Fourier Transform Infrared (FTIR).

The effects of different salting and preservation techniques ofkaşar cheese on cheese quality

The aim of this research is to determine the effects of different salting and preservation techniques on the quality of kasar cheese. Physical, chemical, and microbiological analyses were performed on days 1, 7, 15, 30, 60, 90, and 120 of the maturation of 270 samples of kasar cheese produced for this research. Additionally, sensory analyses were performed on days 30, 60, 90, and 120 of maturation. The total number of aerobic mesophilic bacteria, Lactococcus, Staphylococcus-Micrococcus, and psychotropic bacteria was lower and the number of yeast-mold and lactobacilli was higher in cheese examples salted in a boiler than those salted in brine. Salting in brine can be used alongside salting in a boiler. The cheese salted in a boiler can be preserved for 90 days by waxing it with respect to sensory features. Vacuum-packed cheese can be preserved for 60 days, whereas cheese salted in brine can be preserved for 60-120 days. It has been determined that vacuum-packed and wax-covered cheese does not have a negative effect on the quality of the cheese, nor is maturation delayed. It has been concluded that cheese wax can be used as an alternative packaging material along with vacuum packaging.

Determination of trace aflatoxin M1 levels in milk and milk products consumed in Turkey by using enzyme-linked immunosorbent assay

Aflatoxin M1 (AFM1) levels in milk and milk products (kasar cheese, tulum cheese, dil cheese, cream cheese, white cheese) consumed in Turkey were determined in this study by using enzyme-linked immunosorbent assay (ELISA). Extraction procedure was optimised to obtain high extraction efficiency. Recovery experiment was also performed to test the suitability of the extraction system and it was observed that % recovery values for AFM1 were higher than 92%. The method used in this study was simple and suitable for the detection of AFM1 in these matrices. Results found from the samples were compared with the requirements of Turkish Food Codex (TFC). As much as 42.16% of cheese samples analysed were contaminated while 61/77 milk samples were found to be contaminated with AFM1 in the range of 0.005–0.410 µg/L. It was found that five white cheese, one kasar cheese and four milk samples exceeded the criteria of 0.5 μg/kg for cheese and 0.05 μg/L for milk set by TFC.

Incidence of Listeria monocytogenes and Escherichia coli O157:H7 in two Kasar Cheese processing environments

This study was designed to determine the presences of two environmental pathogens in two dairy factories in Sakarya, Turkey. A total of 264 environmental samples, raw milk and cheese samples were taken at four different seasons. According to the results, Listeria monocytogenes or Escherichia coli O157:H7 was isolated from 26 or 2.7% of the samples collected from both factories, respectively. None of the cheese or curd samples were found to be positive for Listeria or E. coli O157:H7. However, 50% of raw milk samples contained Listeria innocua. Listeria was mostly isolated from the swap samples taken from the drains or the floors in processing or packaging areas. However, E. coli was also isolated from the swap samples taken from the workers’ hands and gloves as well as the drains and the floor. Only one raw milk sample contained E. coli O157:H7. A higher prevalence of both pathogens was observed in the summer months than in the other months.

Prevalence of Salmonella spp. and Listeria monocytogenes in different cheese types produced in Turkey

PurposeThe present paper seeks to determine the prevalence of Salmonella spp. and Listeria (L.) monocytogenes in several cheese varieties.Design/methodology/approachA total 280 cheese samples (105 white cheese, 70 processed cheese, 45 dil cheese and 60 kasar cheese) purchased from supermarkets in six provinces of Turkey were collected at intervals between March 2007 and February 2008.FindingsThe results showed that 1.9 percent of white cheese samples were contaminated with Salmonella spp, whereas the L. monocytogenes prevalence was 4.8 percent in this type of cheese sample. The prevalence of L. monocytogenes in processed cheese and kasar cheese were found to be 1.4 percent and 1.7 percent, respectively. No Salmonella spp. was isolated from these cheese varieties. Neither Salmonella spp. nor L. monocytogenes were found in dil cheese samples examined.Originality/valueCheese is a ready to eat product that with a low incidence of contamination may pose great public health concerns. Microbiological evaluation of different cheese samples produced with different manufacturing methods and the possible effects of manufacturing methods on the microbiological quality of these cheese samples are the originality criteria of the study. The cheeses were also sold in a very restricted area of Turkey. The results of this study indicate that white cheese has the highest rates of contamination due to the lack of standardized procedures of manufacturing and ripening.

Use of antimicrobial methylcellulose films to control Staphylococcus aureus during storage of Kasar cheese

AbstractOlive leaf extract (OLE) (Olea europaea L.) is a natural product that has antimicrobial effect on many food pathogens. In this study, methylcellulose (MC) based antimicrobial films containing 0.5–3% (w/v) OLE and glycerol (1.6%, v/v) were produced. The effects of OLE amount on the water vapour permeability (WVP), mechanical and antimicrobial properties of the films were investigated. The films were effective against Staphylococcus aureus (ATCC 25923). The OLE in the film solution caused a decrease in WVP and elongation (E), and an increase in tensile strength (TS). The MC films containing 1.5% (w/v) OLE were applied on Kasar cheese slices inoculated with S. aureus. The count of S. aureus decreased 0.68 and 1.22 log cycle at the 7th and 14th days, respectively. Copyright © 2009 John Wiley & Sons, Ltd.

Effect of Using Attenuated Lactic Starter Cultures on Lipolysis and Proteolysis in Low Fat Kasar Cheese

Bu çalışmada olgunlaştırmayı hızlandırmak, yapı ve tadı iyileştirmek amacıyla az yağlı kaşar peyniri üretiminde dondurularak yardımcı kültür haline getirilmiş L. casei and L. helveticus mikroorganizmaları kullanılmıştır. Az yağlı % 11 yağ ve tam yağlı % 28 yağ olarak üretilen ve 90 gün süreyle 5±1°C’de depolanan peynirler; fiziksel, kimyasal ve duyusal nitelikler yönünden incelemeye alınmıştır. Araştırma sonuçlarına göre; yardımcı kültür kullanımı az yağlı peynirlerin genel bileşimini değiştirmemiş ancak duyusal niteliklerini iyileştirmiş ve L. helveticus ‘ un kullanıldığı örnekte daha belirgin olmak üzere olgunlaşma süresini kısaltmıştır

Effect of Microencapsulation on Viability of Lactobacillus acidophilus LA‐5 and Bifidobacterium bifidum BB‐12 During Kasar Cheese Ripening

The viability of encapsulated Lactobacillus acidophilus LA‐5 and Bifidobacterium bifidum BB‐12 by emulsion or extrusion techniques in Kasar cheese was investigated. The microbiological, biochemical and organoleptic properties of cheeses were assessed throughout 90‐day storage. Results showed that the viability of probiotic bacteria was maintained to a great extent by microencapsulation. No difference was noted between the two encapsulation techniques with regard to bacterial counts, proteolysis and organoleptical properties of the final products. Scalding caused a drastic decline in the counts of probiotic bacteria in all cheeses. Following scalding, while the numbers of nonencapsulated probiotic bacteria decreased continuously in the control cheese, the numbers of encapsulated bacteria remained well above the threshold for a minimum probiotic effect (107 cfu/g).

Survey of lead, cadmium, iron, copper and zinc in Kasar cheese

Lead, cadmium, iron, copper and zinc contents of Kaşar cheese sold in the markets of Ankara, Turkey, were determined over 12 months. A total of 240 samples comprising 10 different brands were analysed. Graphite-furnace atomic absorption was employed for the determination of lead and cadmium, and flame atomic absorption for iron, copper and zinc. The mean (range) of the lead, cadmium, iron, copper and zinc content of the samples were 86 (10–421) μg kg-1, 1.8 (0.3–8.3) μg kg-1, 4.2 (1.0–14.1) mg kg-1, 0.7 (0.3–1.6) mg kg-1 and 37.7 (26.5–63.0) mg kg-1, respectively. The samples in November, December and January contained higher amounts of lead than those in other months (p < 0.01). Moreover, important differences existed in lead content of the samples between different cheese producers (p < 0.01). The differences in cadmium and iron content of the samples for different months were important (p < 0.01). The iron content of the samples among manufacturers also varied significantly (p < 0.01). However, there were no significant differences in copper and zinc contents of the samples over 12 months (p > 0.05). These findings suggested that some contamination occurred during milk production and/or manufacturing of cheese depending on the equipment used. For a consumption of 100 g Kaşar cheese, one would ingest approximately 8.6 μg (4% of the provisional tolerable daily intake, PTDI) of lead, 0.2 μg (0.3%) of cadmium, 0.4 mg (0.9%) of iron, 0.07 mg (2%) of copper and 3.8 mg (6%) of zinc. Therefore, it was concluded that Kaşar cheese is not a significant contributor to the intake of investigated heavy metals.