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Cheese Samples (cheese + sample)
Selected AbstractsUse of a ,-glucan hydrocolloidal suspension in the manufacture of low-fat Cheddar cheese: manufacture, composition, yield and microstructureINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2004G. Konuklar Summary Low-fat Cheddar cheese was manufactured using a , -glucan, hydrocolloidal fat replacer denoted as Nutrim. The composition, production efficiency, microstructure, and utility of replacing fat with Nutrim were examined. Cheese samples (designated as Nutrim-I, and Nutrim-II) containing Nutrim were produced with mean fat levels of 6.84 and 3.47%, respectively. A low-fat cheese was also produced as a control with a mean fat level of 11.2%. Nutrim-II cheese had significantly higher moisture, salt, and ash contents as compared with the low-fat control cheese. The low-fat control cheese had a higher yield normalized for 54% moisture and 1.5% salt content as compared with the Nutrim-II cheese. Scanning electron microscopy revealed smaller and more uniform fat droplet voids in the Nutrim cheese than the low-fat control, and a more dense, noncontinuous background protein matrix with globular clusters suggesting a physical buffering afforded by the presence of the , -glucan hydrocolloid or its associated water. [source] Common components and specific weight analysis and multiple co-inertia analysis applied to the coupling of several measurement techniquesJOURNAL OF CHEMOMETRICS, Issue 5 2006M. Hanafi Abstract The present paper compares two multiblock techniques: the Common Components and Specific Weights Analysis (CCSWA) and the Multiple Co-inertia Analysis (MCoA). Both methods are used to (1) to investigate the relationships among various data tables and (2) to extract latent variables from information of different nature, reflecting different facets of a food product. Our objective is to study the ability of these methods to extract, from a set of data tables, latent characteristics which are representative of the whole modifications brought to a complex system (food product) by a modification of a given process factor. The comparison of these methods is based on the investigation of their conceptual framework by particularly highlighting new properties of CCSWA. Moreover, the two techniques of analysis are compared on the basis of a case study in cheese processing where each cheese sample is described by different kinds of measurements. Copyright © 2007 John Wiley & Sons, Ltd. [source] Optimization of culture conditions for glucose oxidase production by a Penicillium chrysogenum SRT 19 strainENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2010Ragini G. Bodade Abstract The enzyme glucose oxidase (GOD) has been used for a variety of biotechnological applications in food and pharmaceutical industries. In this study, the optimization of extracellular GOD production was carried out in a Penicillium chrysogenum SRT 19 strain isolated from contaminated and decaying cheese samples. Maximum GOD production was attained at pH 6 and 20°C in fermentation broth after 72,h of incubation. The effects of metal ions and sugars were screened for the induction of higher GOD production. The results revealed that glucose and lactose give the highest production of enzyme (0.670 and 0.552,U/mL, respectively) as compared with other sugars (sucrose, cellulose, mannitol and fructose). Out of the seven metal ions studied, CaCO3 (1.123,U/mL) and FeSO4 (0.822,U/mL) act as modulators, while MgSO4 (0.535,U/mL), CuSO4 (0.498,U/mL), HgCl2 (0.476,U/mL), ZnSO4 (0.457,U/mL) and BaSO4 (0.422,U/mL) yield lower production. The study therefore suggests that a strain of P. chrysogenum SRT 19 can be used as a new strain for GOD production. [source] Shelf life of Turkish whey cheese (Lor) under modified atmosphere packagingINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2009HASAN TEM In this study, the shelf life of Lor cheese stored under different atmosphere compositions was assessed and compared. Lor cheeses were held in four different atmospheres containing: vacuum packaging (VP), 40% CO2/60% N2, 60% CO2/40% N2 and 70% CO2/30% N2 (modified atmosphere packaging). Control cheeses were stored in air. All cheese samples were kept in the refrigerator at 4°C for 45 days and investigated for physicochemical, microbiological and sensory properties. The acidity index value was significantly higher (,P < 0.05) in the control and vacuum packaged samples than in those stored for the same period under CO2. Microbiological results showed that modified atmosphere packaging delayed microbial growth compared with air and VP samples. Of the three modified atmospheres, gas mixtures 60% and 70% CO2 were the most effective for inhibition of growth of micro-organisms. Sensory evaluation (odour and taste) results showed that Lor cheese packaged under modified atmosphere packaging (60% CO2/40% N2 and 70% CO2/30% N2,) retained good characteristics for 45 days of storage, while vacuum and control samples were sensorily unacceptable after 10 days of storage. [source] Detection of aflatoxin M1 in milk and dairy products consumed in Adana, TurkeyINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 1 2009ISIL VAR A total of 70 dairy products consisting of 20 sterilized milk, 10 butter, 20 white cheese and 20 Kashar cheese samples were analysed for aflatoxin M1 (AFM1) by enzyme-linked immunosorbent assay (ELISA). The detection limit was 5 ng/L for milk and 25 ng/kg for butter, white cheese and Kashar cheese. Of the 70 dairy products analysed, AFM1 in 49 samples (70%) was found to range from 10 to 388 ng/kg. Moreover, AFM1 levels in three samples of milk, two samples of butter, one sample of white cheese and one sample of Kashar cheese were found to be higher than the Turkish legal limits. [source] Technological characterization of the natural lactic acid bacteria of artisanal Turkish White Pickled cheeseINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 2 2008ELIF DAGDEMIR The aim of this study was to characterize the lactic acid bacteria (LAB) isolated from White Pickled cheeses produced with traditional methods; and to improve the quality of cheesemaking with a selection of bacterial cultures from artisanal White cheeses. LAB were isolated and identified from 30 White Pickled cheese samples collected from various cities in Turkey. Also, the numbers of several microbial groups (total aerobic mesophilic bacteria, LAB, enterococci, coliforms, moulds and yeasts) of cheese samples were enumerated. Lactobacilli, lactococci and enterococci were the most abundant microbial groups. The numbers of Enterococcus and Lactobacillus isolates were higher than those of the other LAB. Enterococcus faecalis (24.43%), Enterococcus faecium (17.61%) and Lactobacillus fermentum (19.88%) isolates were the most frequently isolated species. Lactococcus strains showed the highest acidifying activity, followed by Enterococcus and Lactobacillus strains. Proteolytic activity of Enterococcus faecalis strains was higher than that of the other enterococci species, except Enterococcus avium strains. Within lactobacilli strains, the highest mean proteolytic activity was that of Lactobacillus bifermentans, Lactobacillus brevis and Lactobacillus casei strains. [source] The effects of starter culture on chemical composition, microbiological and sensory characteristics of Turkish Ka,ar Cheese during ripeningINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 4 2007DURMU Ka,ar cheese samples were produced from raw milk and starter culture-added pasteurized milk. Chemical, microbiological and organoleptic properties of ka,ar cheeses were analysed at certain times during the ripening periods (on the 1st, 7th, 15th, 30th, 60th, 90th days). Generally, chemical parameters were not affected by starter culture. The pH, ripening index, water-soluble nitrogen and non-protein nitrogen did not show significant differences between the cheese samples. The addition of starter affected the microbiological quality of the cheeses. Starter culture-added ka,ar cheeses contained low levels of total aerobic mesophilic bacteria, moulds and yeasts, and coliforms, and achieved higher organoleptic scores than those of cheeses made from raw milk. The starter cultures contributed to acidity and microbial quality of the cheese. [source] Effect of different starches on rheological and microstructural properties of (II) commercial processed cheeseINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 12 2008Darshan Trivedi Summary A range of commercial processed cheese samples containing starch were prepared on a Rapid Visco Analyser (RVA) and on a pilot plant scale. This work clearly demonstrated that it was possible to manufacture processed cheese with part of the protein replaced with potato starch, while maintaining similar rheological attributes (firmness) to those of the control and an acceptable melt index. Sensory evaluation showed that, although the reduced-protein cheese samples had a good, clean, fresh flavour that was comparable with that of the control, at high starch concentrations the starch-containing processed cheese had a pasty texture and tended to stick to the wrapper. [source] Direct detection of bacterial pathogens in representative dairy products using a combined bacterial concentration-PCR approachJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004K.A. Stevens Abstract Aims:, To develop a simple, rapid method to concentrate and purify bacteria and their nucleic acids from complex dairy food matrices in preparation for direct pathogen detection using polymerase chain reaction (PCR). Methods and Results:, Plain non-fat yogurt and cheddar cheese were each seeded with Listeria monocytogenes or Salmonella enterica serovar. Enteritidis in the range of 101,106 CFU per 11-g sample. Samples were then processed for bacterial concentration using high-speed centrifugation (9700 g) followed by DNA extraction, PCR amplification, and amplicon confirmation by hybridization. Bacterial recoveries after centrifugation ranged from 53 to >100% and 71 to >100% for serovar. Enteritidis and L. monocytogenes, respectively, in the non-fat yogurt samples; and from 77 to >100% and 69 to >100% for serovar. Enteritidis and L. monocytogenes, respectively, in the cheddar cheese samples. There were no significant differences in recovery efficiency at different inocula levels, and losses to discarded supernatants were always <5%, regardless of dairy product or pathogen. Conclusions:, When followed by pathogen detection using PCR and confirmation by amplicon hybridization, detection limits of 103 and 101 CFU per 11-g sample were achieved for L. monocytogenes and serovar. Enteritidis, respectively, in both product types and without prior cultural enrichment. Significance and Impact of the Study:, This study represents progress toward the rapid and efficient direct detection of pathogens from complex food matrices at detection limits approaching those that might be anticipated in naturally contaminated products. [source] Occurrence of Staphylococcus and enteropathogens in soft cheese commercialized in the city of Rio de Janeiro, BrazilJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2002V.S. Araújo Aims: To investigate the presence of Staphylococcus aureus, enteropathogenic Escherichia coli (EPEC), Aeromonas spp. and Yersinia spp. in soft cheese commercialized in Rio de Janeiro, Brazil. Methods and Results: A total of 45 samples of cheese from three different brands marketed in Rio de Janeiro city were analysed for faecal coliform levels using the Most Probable Number (MPN) technique. The samples were also analysed using conventional methodology for the investigation of food-borne pathogens. High levels of faecal contamination were detected in 95·5% of cheese samples. Staphylococcus aureus was isolated from 20% of samples, of which 17·7% were above the limits allowed by Brazilian legislation. Aeromonas hydrophila and Aer. caviae were detected in 17·7% of the samples. Yersinia spp. were not found in this study. EPEC was isolated from 21·1% of the samples and the most frequently found serogroups were O127, followed by O55 and O26. Conclusions: Our results showed that 95·5% of cheese samples had high levels of faecal coliforms. The isolation of Staph. aureus, serogroups of EPEC and Aeromonas spp. suggested that the soft cheese commercialized in the city of Rio de Janeiro may represent a health risk for the consumers. Significance and Impact of the Study: These results suggest that soft cheese may act as an important vehicle of transmission for well-established pathogens. [source] BIOGENIC AMINE CONTENT OF SOME TURKISH CHEESESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2002FÜGEN DURLU-ÖZKAYA Biogenic amines in ten samples of Ka,ar (aged), five samples of Ka,ar (fresh), four samples of Mihaliç, nine samples of Van Otlu (herbed), nine samples of Örgü, nine samples of Urfa and six samples of Civil cheeses were obtained from local supermarkets of Ankara. Tryptamine (TRY), phenylethylamine (PHA), putrescine (PUT), cadaverine (CAD), histamine (HIT), tyramine (TYA), spermine (SPM) and spermidine (SPD) contents of Turkish cheese samples were screened by high performance liquid chromatography (HPLC). PUT, CAD, HIT, TYA and SPD were the predominant biogenic amines in maturated Ka,ar (aged), vacuum-packed Ka,ar (fresh), Mihaliç, Otlu (herbed) and Örgü cheeses. PHA, CAD, TYA and SPD were the predominant biogenic amines in Urfa cheese samples. Civil cheeses were found to contain the highest HIT and TYA content with an average of 94.76 mg/100 g and 138.16 mg/100 g, respectively, much higher than the toxic dose. HIT level of Mihaliç cheeses were also higher than the accepted limit. The concentration of amines in all other cheeses was much lower than the toxic dose limits. [source] Electronic Nose Technology in Quality Assessment: Predicting Volatile Composition of Danish Blue Cheese During RipeningJOURNAL OF FOOD SCIENCE, Issue 6 2005Jeorgos Trihaas ABSTRACT This work describes for the 1st time the use of an electronic nose (e-nose) for the determination of changes of blue cheeses flavor during maturation. Headspace analysis of Danish blue cheeses was made for 2 dairy units of the same producer. An e-nose registered changes in cheeses flavor 5, 8, 12, and 20 wk after brining. Volatiles were collected from the headspace and analyzed by gas chromatography-mass spectrometry (GC-MS). Features from the chemical sensors of the e-nose were used to model the volatile changes by multivariate methods. Differences registered during ripening of the cheeses as well as between producing units are described and discussed for both methods. Cheeses from different units showed significant differences in their e-nose flavor profiles at early ripening stages but with ripening became more and more alike. Prediction of the concentration of 25 identified aroma compounds by e-nose features was possible by partial least square regression (PLS-R). It was not possible to create a reliable predictive model for both units because cheeses from 1 unit were contaminated by Geotrichum candidum, leading to unstable ripening patterns. Correction of the e-nose features by multiple scatter correction (MSC) and mean normalization (MN) of the integrated GC areas made correlation of the volatile concentration to the e-nose signal features possible. Prediction models were created, evaluated, and used to reconstruct the headspace of unknown cheese samples by e-nose measurements. Classification of predicted volatile compositions of unknown samples by their ripening stage was successful at a 78% and 54% overall correct classification for dairy units 1 and 2, respectively. Compared with GC-MS, the application of the rapid and less demanding e-nose seems an attractive alternative for this type of investigation. [source] Method Development for Assessing the Complete Process of Crumbling Cheese Using Hand EvaluationJOURNAL OF FOOD SCIENCE, Issue 4 2004S. Sandra ABSTRACT: Cheese sensory evaluation was conducted by trained panelists (n= 8) on 4 commercial cheese samples (feta, Monterey Jack, 2 brands of Queso Fresco) in duplicate. Fifteen descriptors, capturing the entire process of crumbling cheese, were tested. Degree of crumbliness was defined as the ease by which the sample breaks apart during manipulation by rolling the sample using replicated circular movements, with the thumb, forefinger, and middle finger, 5 times. Using principal component analysis, 4 components were extracted and moistness, crumbliness, color, cohesiveness, irregularity, and oiliness were the main descriptors differentiating the samples. Panelists' performances were not significantly different (P, 0.05), and each subject used the method consistently for crumbliness. [source] SENSORY PROFILE OF FLAVOR AND ODOR CHARACTERISTICS IN RONCAL CHEESE MADE FROM RAW EWE'S MILKJOURNAL OF SENSORY STUDIES, Issue 5 2002PATRICIA LARRÁYOZ ABSTRACT Roncal cheese is made from raw ovine milk and is regulated by an Appellation of Origin. This cheese variety is quite popular with consumers because of its special properties, which are unlike those of other ewe's-milk cheeses. To date there have been no studies aimed at characterizing the flavor and odor attributes of Roncal cheese. To remedy this situation, sensory analysis has been performed using Roncal cheese samples collected from artisanal and industrial cheese-making establishments. The cheeses were made at three different times of year (winter, spring, and summer) and were ripened for four or eight months. Sensory descriptors were generated, and after discussion suitable descriptors for describing and discriminating among Roncal cheese samples were selected by multivariate analysis. In all, 19 descriptors were employed, namely: odor: cream, meat broth, olive, toffee, liquid caramel, toasted, acetic acid, sweat, acidified milk, ammonia, leather, stable straw, wool, and odor intensity. flavor: characteristic flavor, acetic acid, sweat, butyric acid, and flavor intensity. [source] SENSORY AND INSTRUMENTAL EVALUATIONS OF TEXTURE IN CHEESES MADE FROM OVINE MILKS WITH DIFFERING FAT CONTENTSJOURNAL OF SENSORY STUDIES, Issue 2 2002A. IRIGOYEN ABSTRACT The present study considers the influence of reducing the fat content of ovine milk on the sensory and instrumental texture characteristics of the resulting cheeses. Three manufacturing runs were performed. In each run three cheese batches were manufactured using milks with differing percentage fat contents (8%, 4%, and 2% fat). Analysis of cheese samples was performed at 60, 90, and 120 days of ripening. The instrumental method used to evaluate cheese texture was uniaxial compression at constant speed, taking readings of stress, strain, and modulus of elasticity (E). Statisticalanalysis revealed differences forboth the differentfat contents and the ripening times considered. Instrumental parameter values increased with lower cheese fat contents; with a 20% reduction in the fat to dry matter content from full-fat to reduced-fat cheeses, resulting in a 35% increase in maximum stress and in the slope of the stress-strain curve at the end of ripening. The greatest sensory differences between samples were recorded for firmness. [source] Differentiation among various kinds of cheese by identification of casein using HPLC-chip/MS/MS,JOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2010Martin Franc Abstract In proteomics, proteins can be identified by enzymatic cleavage of the target protein using an enzyme of the known specificity (primarily trypsin), sequencing the obtained specific peptides by MS and comparing the amino acid sequence of the peptides with a protein database. The sophisticated approach described above was used in this study to determine and verify the original species of cheeses. Proteins were extracted from three different cheese samples which were produced from cow, sheep and goat milks. The isolated proteins were cleaved with trypsin and the peptides obtained were sequenced and identified by a HPLC-chip/MS/MS microfluidic system. Two different extraction methods and two various chromatographic sorbents packed in plastic chips were studied. ,-Lactoglobuline and four kinds of casein were found in the cheese samples. The species of ,-casein were identified unambiguously in all the three cheese samples and, thus, ,-casein can be used to determine the origin of milk of the cheese. The other proteins found in the samples show very similar primary structures and cannot be recommended for identification of the cheese milk origin. [source] RHEOLOGICAL PROPERTIES OF MOZZARELLA CHEESE DETERMINED BY CREEP/RECOVERY TESTS: EFFECT OF SAMPLING DIRECTION, TEST TEMPERATURE AND RIPENING TIMEJOURNAL OF TEXTURE STUDIES, Issue 3 2009MARÍA LAURA OLIVARES ABSTRACT The viscoelastic properties of mozzarella cheese using a creep/recovery test considering different sampling directions (parallel and perpendicular to protein fiber orientation), test temperatures (20, 30 and 40C) and ripening times (1, 8, 15, 29 and 36 days) were studied. Creep data were interpreted by a Burger model of four parameters. A semiempirical approach was proposed to obtain the contribution of each main compliance to the total deformation of the system. Creep tests at different temperatures allowed gaining a better understanding of changes that occur in the cheese matrix during heating and ripening. Sampling direction did not affect any of the parameters studied. Finally, it was clearly observed that cheese matrix behaves as a quite different physicochemical system depending on temperature. Therefore, it is recommended to carry out the rheological tests at different temperatures to evaluate appropriately the viscoelastic properties of mozzarella cheese. PRACTICAL APPLICATIONS Mozzarella cheese must have certain characteristics to be used on pizzas and on other prepared foods that use the cheese in melted state. The protein chains in the mozzarella curds coalesce into large strands that are oriented in the direction of stretching. For this reason, mozzarella cheese has an anisotropic structure. Therefore, it is relevant to determine the effect of protein fiber orientation on the rheological properties. Valuable information may be obtained through the creep/recovery test of mozzarella cheese samples to study its rheological properties and to explain molecular mechanisms that occur during ripening or melting processes considering sampling direction. [source] Detection of enterotoxigenic Staphylococcus aureus isolates in raw milk cheeseLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2007P. Cremonesi Abstract Aim:, To develop an easy, rapid and efficient DNA extraction procedure for Staphylococcus aureus detection with a low number of steps and removing completely the PCR inhibitors, applicable to raw milk cheese samples, and to compare phenotypical and genotypical method to detect Staph. aureus isolates and staphylococcal enterotoxins (SEs) production. Methods and Results:, A total of 33 bovine and caprine raw milk cheese samples were analysed by means of both classic microbiological and molecular techniques. All samples were positive for Staph. aureus contamination. The DNA extraction protocol optimized was found to achieve a detection limit of 100 CFU g,1 for Staph. aureus. None of the samples tested with immunological assays contained SEs but in 14 of 33 samples a mixture of se positive (sea, sec, sed, seg, sel, sej) isolates were identified. Conclusions:,Staphylococcus aureus is a food-borne pathogen mainly detected in finished dairy products. The rapid and efficient detection of Staph. aureus isolates from dairy products is essential for consumer safety. The direct detection of pathogens from food is possible with careful attention to sample preparation and nucleic acid amplification optimization. Significance and Impact of the Study:, This study shows that raw milk cheese samples can be tested for Staph. aureus contamination with a rapid, simple and reproducible procedure. [source] | |||||||||||||