Hard Cheese Research Articles

Impact of Extending Hard-Cheese Ripening: A Multiparameter Characterization of Parmigiano Reggiano Cheese Ripened up to 50 Months.

Extending ripening of hard cheeses well beyond the traditional ripening period is becoming increasingly popular, although little is known about the actual evolution of their characteristics. The present work aimed at investigating selected traits of Parmigiano Reggiano cheese ripened for 12, 18, 24, 30, 40 and 50 months. Two cheeses per each ripening period were sampled. Although moisture constantly decreased and was close to 25% in 50-month cheeses, with a parallel increase in cheese hardness, several biochemical changes occurred involving the activity of both native and microbial enzymes. Capillary electrophoresis demonstrated degradation of αs1- and β-casein, indicating residual activity of both chymosin and plasmin. Similarly, continuous release of free amino acids supported the activity of peptidases deriving from lysed bacterial cells. Volatile flavor compounds, such as short-chain fatty acids and some derived ketones, alcohols and esters, evaluated by gas chromatography with solid-phase micro-extraction, accumulated as well. Cheese microstructure was characterized by free fat trapped in irregularly shaped areas within a protein network, with native fat globules being no longer visible. This study showed for the first time that numerous biochemical and structural variations still occur in a hard cheese at up to 50 months of aging, proving that the ripening extension deserves to be highlighted to the consumer and may justify a premium price.

Determination of Biogenic amines in hard cheeses by High performance liquid chromatography

This study evaluated chemically the quantity of six biogenic amines histamine, tyramine, puterscine, cadaverine, tryptamine and phenylethylamine in forty hard cheese samples (Chedder and Ras) (20 of each) sold in retail markets in Zagazig City Sharkia Governorate using high performance liquid chromatography (HPLC) and correlation with compositional quantity of cheese (pH, salt%, moisture% and acidity%). Our results showed the mean values of pH, salt, moisture and acidity were (5.5±0.02 and 4.79±0.11), (1.53±0.04 and 4.42±0.05%), (40.45±0.24 and 38.64±0.34%) and (0.84 ±0.01 and 1.70±0.04%) in Chedder and Ras cheese samples, respectively. The mean values of total biogenic amines were 12.65±2.7and 28.95±4.6 mg/100g in Chedder and Ras cheese samples, respectively. There was a negative correlation between (pH value and moisture %) and biogenic amines production but the positive correlation was found between (salt and acidity %) and biogenic amines production. Finally it was found that all Chedder and Ras cheese samples were accepted according to maximum permissible limit of Egyptian organization standard (EOS, 2007) which is 20mg/100g. All samples were accepted according to maximum permissible limit of Food and Drug Administration (FDA, 2001) which is 10mg/100g except 60 and 90 % of Ras cheese samples are accepted for histamine and puterscine, respectively. On conclusion, optimization and standardization of milk quality and hygiene during cheeses manufacturing and storage should be taken for human safety.

The influence of the composition of bacterial starter cultures on the maturation process and the quality of hard rennet cheese

The object of research is the starter culture used in the production of solid rennet cheese.One of the most problematic places is the selection of the number and composition of bacterial starter cultures for the production of hard cheeses with a low temperature of second heating.During the study, analysis and synthesis methods were used – when studying the sources of scientific literature on the research topic; laboratory methods (biochemical and microbiological) studies – when determining the optimal composition of bacterial starter cultures; organoleptic methods – in determining the quality of the finished product; methods of mathematical statistics – for processing research results.During the study, it was shown that in order to improve the coagulation of milk, which underwent high-temperature processing, it is necessary to add a double dose of calcium chloride and rennet and 0.1 % bacterial fermentation to the milk mixture. In addition, the mixture must be kept at 12 hours at 10–12 °C to improve the cheese ability of milk.As a research result, it is found that with an increase in the total amount of bacterial starter culture, there is an increase in the acidity of milk before coagulation, a decrease in the duration of mixing of the grain after the second heating, and an increase in the acidity of whey at all stages of the technological process.The most successful should be considered samples of cheeses made from sourdough, which included 1.5 % of the complex of mesophilic lactobacilli and 0.3 % of thermophilic lactobacilli Lb. acidophilus, the use of which ensures the formation of higher organoleptic characteristics of rennet cheese.The use of highly effective bacterial starter cultures, the increased moisture content in the product and the maturation of the product at elevated temperatures make it possible to obtain cheese with a reduced ripening time of 25–30 days.Thus, as a research result, optimal technological parameters are established that will allow to obtain rennet cheeses with a low temperature of the second heating of high quality.

Three-dimensional analysis of bitemarks: A validation study using an intraoral scanner

Conservation of the three-dimensional aspect of bitemarks optimizes their analysis. Although bitemarks could be recorded with a surface scanner, in clinical dentistry, intraoral scanners are used as an alternative to conventional dental impressions. Here we assess the reproducibility and the reliability of a three-dimensional bitemark analysis protocol using an intraoral scanner. Twenty-seven volunteers bit on different materials: dental wax, hard cheese, chocolate and apple. Then, bitemarks and dentitions were scanned with the PlanMeca® Emerald intraoral scanner and the scans obtained were exported into the mesh comparison software, CloudCompare®, which can generate overlays automatically. For this purpose, dentitions were aligned and compared with the indentations. The meshing and non-meshing areas were visualized using a colorimetric scale. First, the same blinded observer compared the bitten materials by analyzing 256 meshing areas for each. Secondly, comparisons of bitemarks from wax were analyzed in a randomized blinded study involving four observers (dentist, dental student, forensic scientist and police officer) and predictive values were calculated. The wax support obtained the best result and apple the worst. The rate of correct classifications was high and misclassification was rare. For the all observers, negative predictive values were near 100%. Positive predictive values were more variable. Moreover, the work clearly highlighted the importance of experience in odontology.

One Health Approach in Traditional Milk Production as a Part of Steps towards SDGs

The production of milk and cheese assumes activities in the field of agricultural production, veterinary health, and the use of milk and dairy products has public health significance, and can be viewed through the "one health" concept. The aim of the paper is to underline public health and sustainability significance of interconnection among agriculture, veterinary and technology. Production of hard cheese with added value from milk produced in organic and self-sustaining systems research the risks, advantages and possibilities of traditional cheese production and focused on creating conditions for organic milk and hard cheese with added value production, with precisely defined conditions: isolating land plots, livestock farms and processing facilities from possible sources of pollution, water quality, harmonized development of plant and animal production and the capability of producers for organic agriculture with the obligation to constantly innovate knowledge. The new products ensure the employment and livelihood of people in the countryside, the economic prosperity of small family farms, link the activities in the field of veterinary health and agricultural production, contribute to the development of risk-management technology, healthy chooses and compatible with SDGs. 
 Keywords: One Health approach, Traditional Milk Production, sustainability, Healthy Choices, SDGs

Determination of grated hard cheeses adulteration by near infrared spectroscopy (NIR) and multivariate analysis

Cheese is a dairy product of massive consumption and is commonly commercialised as grated cheese. Adulteration of cheese reduces its quality and consequently, decreases its nutritional value. This work proposes an analytical tool to determine the adulteration of cheeses with higher levels of additives than those permitted (cellulose and silicon dioxide) and non-authentic substances used to increase weight and volume such as wheat-flour, wheat-semolina and sawdust. The proposed methodology is based on near infrared spectroscopy (NIR) and multivariate classification analysis. Excellent classification results were obtained with partial least squares discriminant analysis (PLS-DA) as adulterated samples were discriminated from original (unadulterated) samples. The prediction ability was assessed with adulterated commercial grated cheeses. The screening tool represents a fast, reliable and affordable way to perform quality control of grated cheeses to avoid consumer deception based on nutritional detriment and misleading labelling.

Penicillium commune affects textural properties and water distribution of hard and extra-hard cheeses.

We analyzed the effects of growth of Penicillium commune, one of the most frequent fungal species associated with cheese, on the water diffusion and texture of hard and extra-hard cheeses. A total of 36 hard cheese blocks and 36 extra-hard cheese blocks were manufactured, salted at different levels (0.5, 1.25 and 2% w/w), and assigned to different treatments (control and inoculated). Cheese texture was analyzed using a penetration needle probe at 2 and 5 weeks after ripening. Firmness, defined as the maximum force detected in the penetration probe, was higher in both hard and extra-hard inoculated cheese blocks compared with the control. In addition, the presence of fungal growth on cheese rind increased the total work of penetration (a measure of resistance to probe penetration), but only in extra-hard cheeses, suggesting that the moisture of cheese might be affecting the growth capacities and performance of P. commune. The change in textural properties of cheeses was linked to desiccation of the upper 0.5-cm rind layer mediated by P. commune.

Short communication: Clostridial spore counts in vat milk of Alpine dairies

One of the most severe quality defects in hard and semi-hard cheese, the late blowing defect, is caused by endospore-forming bacteria of the genus Clostridium. To minimize financial losses and waste of resources due to cheese spoilage, raw milk with elevated clostridial spore counts should not be used for the production of certain cheese types. In this context, threshold values of clostridial spore concentrations that cause quality defects in cheese are still under debate. To improve our understanding about late blowing defects, further information on the correlation between clostridial spore concentrations in milk and cheese quality is indispensable. Thus, the aim of this study was to monitor the microbiological quality of milk used for Alpine cheese production regarding clostridial endospore levels to facilitate the establishment of threshold spore concentrations that guarantee the absence of quality defects in Austrian cheese. For this purpose, we monitored clostridial endospore levels in vat milk of 4 Alpine dairies throughout the summer grazing period in 2018. Surprisingly, we observed almost complete absence of butyric acid-producing clostridia in milk and no blowing defects in cheese. Hence, critical clostridial spore concentrations could not be verified. Moreover, the observed low spore levels reveal that the prohibition of silage feeding and good farming practices effectively minimize clostridial endospore counts in milk and ensure the manufacture of high-quality cheese even if technological possibilities are limited.

Application of vacuum solid-phase microextraction for the analysis of semi-hard cheese volatiles

Solid-phase microextraction (SPME) is a well-established technique in the analysis of food volatile compounds, usually performed for qualitative analysis. This paper presents an elaboration of conditions for SPME analysis of main volatile compounds in hard cheese and an evaluation of suitability of vacuum to improve the transfer of volatile compounds towards SPME fiber. Compounds representing the main groups of hard cheese volatiles were investigated: 1-pentanol, butanoic acid, 2,3-butanedione and 2-heptanone. Parameters for SPME extraction (temperature, water, sodium carbonate addition, time, vacuum) were evaluated. Application of vacuum had a positive effect on all analytes when extraction was performed from water, but in the cheese matrix the effect was significant only for butanoic acid. Extraction time was the most significant factor for extraction efficiency in examined cheeses, while temperature had a minor effect on the amount of extracted volatiles. The method was applied on Edam, Emmentaler, Gouda and Maasdam cheeses obtained from the market.

Economic indicators of production of semi-hard and hard cheeses in small capacity dairies in Serbia

Animal husbandry has a longstanding tradition in Serbia, and the production of milk and dairy products has a rich legacy. Cow?s milk is used in the manufacture of all kinds of dairy products. Annual global cheese production is about 20 million tons, with cattle milk cheeses produced in large-scale processing plants constituting about 80% of that production. In Serbia, leaders of milk production are small family dairy farms, which contribute 92% of total production, while dairies with large capacity dominate in milk processing. There are 211 milk processing plants of varying capacities in Serbia. The largest amounts of milk are processed by dairy plants 'Imlek' and 'Subotica', while 188 small-scale dairies process 20% of total milk. The subject of this paper is the analysis of the economic indicators of production of semi-hard and hard cheeses in small-capacity dairies in Serbia. To determine the level and structure of production costs of dairy products, the analytical calculation method of per unit processing costs has been used. The study has revealed that the cost price of semi-hard and hard cheeses in small-capacity dairies amounts to 3.33 ?/kg. With 90.83% in the structure of total costs of processing the milk into cheese, the cost of raw materials has the largest share, followed by labor costs with 6.54%. For small-capacity dairies to be able to compete with larger dairies, both in product quality and price, it is crucial to continuously monitor and minimize production costs.

Факторы, влияющие на сохранение качества полутвердых сыров в процессе производственного хранения

Материалы для специалистов молочной промышленности. Технологии переработки молока Оборудование для отрасли. Состояние и тенденции развития рынка молочных продуктов. Новости и события молочной промышленности.

Isolation of enterotoxigenic Staphylococcus aureus harboring seb gene and enteropathogenic Escherichia coli (serogroups O18, O114, and O125) from soft and hard artisanal cheeses in Egypt.

Background:Soft and hard artisanal cheeses are regularly consumed in Egypt. These products are usually processed from raw milk which may harbor many pathogenic and spoilage microorganisms.Aim:To evaluate the safety of some artisanal cheeses in Egypt, such as Ras, Domiati, and Mish, through chemical and microbiological examination.Methods:One hundred and fifty random samples of traditional Ras, Domiati, and Mish cheeses (50 each) were microbiologically and chemically analyzed. Counts of total bacteria, presumptive coliform, staphylococci, yeast, and mold were estimated. Furthermore, isolation of Escherichia coli and Staphylococcus aureus was performed, followed by PCR confirmation; isolates of E. coli were examined for the presence of virulence genes; on the other hand, the detection of the five classical enterotoxin genes of S. aureus was performed using multiplex PCR. Regarding chemical analysis, moisture, salt, and acidity content were measured. Correlations between chemical and microbial findings were investigated.Results:Mean counts of total bacteria, presumptive coliform, staphylococci, yeast, and mold were (2 × 108, 3 × 106 and 1 × 107 ), (3 × 105, 5 × 10 and 5 × 102), (1 × 106, 4 × 105and 1 × 105), (3 × 105, 1 × 105 and 5 × 105), and (7 × 103, 4 × 103 and 3 × 104) for Ras, Domiati and Mish cheeses, respectively. Serological identification of suspected E. coli revealed that E. coli O125 was isolated from Ras and Domiati samples, E. coli O18 was recovered from Ras samples, while E. coli O114 was isolated from Mish samples. PCR results revealed that all detected isolates of E. coli were positive for both iss (increased serum survival) and fimH (type 1 fimbriae) genes. Concerning isolated S. aureus, all examined products were harboring S. aureus enterotoxigenic strains, with seb and sed genes being the most common. The mean values of moisture, salt, and acidity were (30.03, 56.44, and 58.70), (3.30, 6.63, and 7.56) and (0.65, 0.68, and 0.50) for Ras, Domiati, and Mish cheeses, respectively.Conclusion:Enterotoxigenic S. aureus harboring seb gene and enteropathogenic E. coli (serogroups O18, O114, and O125) were frequently isolated from soft and hard artisanal cheeses in Egypt. Therefore, strict hygienic measures should be applied during their manufacture, handing, and distribution.

Diet quality, anthropometrics, and gut microbiota composition in healthy adults

AbstractHuman gut microbiota may affect metabolism and health by synthesizing metabolites and processing of food components. Those processes are specific to genus and species (or even strain), and dietary intake and metabolic state (such as obesity) can affect the composition of gut microbiota. The aim of the study was to assess the effect of dietary patterns and intake of several groups of food products and macronutrients, as well as the impact of anthropometric parameters on gut microbiota composition.The study group consisted of 200 men and women between 31 and 50 years of age. The diet was assessed using three-day dietary records and the dietary pattern was determined with the use of the original score method and two dietary indices, namely the Diet Quality Index – International (DQI-I) and the Healthy Eating Index (HEI). Bacterial DNA was isolated from the feces of the participants and microbiota composition was determined using metagenomic sequencing of the V3–V4 region of the 16S rRNA gene.Dietary indices and intake of energy from macronutrients did not correlate with the Firmicutes to Bacteroidetes phylum ratio. However people with greater abundance of the Firmicutes phylum compared to Bacteroidetes consumed higher amounts of fermented milk beverages, hard cheese, and salt (78%, 48%, 14% higher intake respectively; p < 0.05). A higher diet quality as measured by the diet indices was positively correlated with the relative abundance of the Firmicutes phylum, Bacilli, Clostridia class, Lachnospira, Faecalibacterium, Coprococcus, and Prevotella genus and negatively correlated with the relative abundance of the Bacteroidetes phylum, Bacteroidia class, and Bacteroides genus. Higher dietary fiber intake positively correlated with the relative abundance of the Coprococcus, Lachnospira, and Roseburia genera, whereas energy intake from simple carbohydrates was positively correlated with the relative abundance of the Tenericutes phylum and the Mollicutes class. Energy intake from alcohol correlated positively with the relative abundance of Bacteroidetes phylum and Bacteroides class and correlated negatively with Firmicutes phylum and Clostridia class. Lower waist-to-hip-ratio, body mass index, and fat mass led to higher abundance of the Fecalibacterium genus.Both diet and anthropometric parameters are associated with gut microbiota composition. Associations between diet and the relative abundance of microbiota are nutrient-specific.

On Sugarland: An excerpt and annotation

66 leshea harris’s plays often explore the intricacies of relationships between women. Audiences come to understand the nuances of each character’s personality by observing her in conversation with other women, from mothers and sisters to rivals and mentors. On the page, characters’ affects are also illustrated by Harris’s use of innovative typography; an admonishment might be rendered in large typeface, while a whispered admission might waft down the page in tiny letters. Her new play, On Sugarland, excavates an intergenerational relationship between preadolescent Sadie and her aunt, Odella. For this special issue, we asked Harris to share snippets from the work, annotated with her thoughts on character formation, scene setting, and typographical experimentation. —the editors A On Sugarland An excerpt and annotation Aleshea Harris play 67 excerpt one (A young girl speaks assuredly to herself.) sadie I can make the dead walk.† I can. I can. I can make ’em put theyself back together and remember how to use their muscles and all. I can make ’em take new air into their lungs like it ain’t nothin But I ain’t finna tell nobody how naw What I look like giving out my gifts? I can make the dead walk and I got invisibility O yes Don’t nobody do invisibility like us, huh? Girls like us, we got it down, huh? We kinda like the wind you know we kinda like a shadow you know † I love to begin a work with a juicy image, something strange and suspenseful. This little girl telling us right off the bat that she can do the seemingly impossible should feel like a jolt. we got a frequency other folk can’t pick up on† but we can pick up on each other’s frequency through time, over time, under time our frequencies ain’t stuttin no time can’t nothin stop ’em Nothin I got Great Great Great Gran’s frequency running all through me even though she lived a long time ago Here go her frequency right here in my arm You see it? Here it go in my chest‡ You see it? Sheeid I’m tryna tell you Great Great Great Gran lived on a farm in Civil War times Her mama and daddy were long gone so she had to take care of her little brother and a little sister She wasn’t a slave, technically She had been freed but still had to work for next to nothing and they were all starving so she figured out she could carry messages to the Union soldiers and they’d give her food And didn’t nobody suspect a little black girl † The typography here is sturdy and steady, like a train moving quickly, its boxcars in a row. Sadie doesn’t have time to dilly-dally. The “frequency” moving through her body seems to compel her to speak quickly, too. Like a bullet through a gun, we move. ‡ This line about seeing the frequency in her arm and chest reminds me of a line from Sojourner Truth’s “Ain’t I a Woman” speech, which I once performed in a play. It strikes me that a speech delivered so long ago by Sojourner Truth shows up in some small way in Sadie’s speech here. This transference echoes the effort of Sadie’s monologue to capture the pulse of unnameable energy shared by Black girls and women generations, decades, continents apart. It ain’t stuttin no time! 68 | ALESHEA HARRIS ON SUGARLAND | 69 you know we invisible† you know Didn’t nobody suspect a little black girl was carrying messages. So she told them what she knew and the soldiers gave her hard tack and cheese or whatever they had. So she got her belly full and they got to know when there was whispers of cracker-jack Rebel soldiers taking over people’s drawing rooms and shit. One day, though One day Great Great Great Gran’s headed back from passing along messages Feelin all grown and stuff And she’s got a sack over her shoulder filled with bread and possum meat and maybe even an egg or two so she really feelin...

Санітарно-гігієнічні показники молока-сировини, які впливають на якість сиру

This paper presents the results of monitoring the conditions for obtaining raw milk intended for the production of cheese from various groups of suppliers, which can conditionally be divided into two groups. The first group includes farms with an appropriate level of hygiene requirements for obtaining raw milk. The second group includes suppliers who have deviations from the hygienic requirements for milk production. Possible biological risks in milk production and control measures to prevent them have been identified. The milk sent for the manufacture of cheeses has increased hygiene requirements. A long time passes between the start of milk processing and the release of the finished product, and extraneous microflora that has withstood pasteurization can damage the quality of products and human health. Modes of pasteurization of milk in the production of cheese are much milder and this does not guarantee the death of all pathogenic microorganisms. It has been established that raw milk that is accepted at the Novokakhovsk butter and cheese factory from various groups of suppliers can be used for the production of various products. Milk obtained from cows from dairy farms by microbiological indicators and rennet-fermentation test can be used for the production of hard rennet cheeses. The low quality of raw milk (raw materials of group II) creates serious difficulties for processing enterprises, which must ensure the safety of their final products for human health, so milk from animals from the private sector can be processed into butter or processed cheese. Milk production of appropriate quality and safety in the private sector is possible using a biological hazard control system and the development of control measures to minimize their impact. It is also necessary to orient livestock owners on a systematic definition of hazardous factors and the implementation of measures that significantly affect the safety of milk. Keywords: milk raw materials, hygiene requirements, biological risks, mesophilic microorganisms, somatic cells, fermentation test.

Aflatoxin M1 in Nicaraguan and locally made hard white cheeses marketed in El Salvador

Aflatoxin M1 is a carcinogenic and genotoxic metabolite of Aflatoxins present in food contaminated by fungi for lactating cattle, it is excreted through milk and when used to make cheese, the toxin will also be transferred to the dairy. The contamination of unripened hard white cheese with AFM1 seems to vary according to the season of the year, possibly due to the change of foodstuff, from fresh pasture in the rainy season to dried foods in the dry season and vice versa. This research determined both the prevalence and contents of AFM1 in cheeses of local and Nicaraguan origin marketed in El Salvador, as well as the changes occurred according to the season and the association between levels of AFM1 with meteorological parameters. The significantly higher prevalence of AFM1 contamination in both local cheeses and Nicaraguans, was found in the dry season and the lowest in the rainy season (41 % vs. 20 %; 31 % vs. 0%, respectively), the same trend was observed in AFM1 contents (0.076 vs. 0.036 μg/kg; 0.050 vs. 0.021 μg/kg, respectively). A significant association was demonstrated between levels of AFM1 with the averages of accumulated rainfall and relative humidity according to the sampled season. The prevalence of AFM1 in cheeses indicate that El Salvador and Nicaragua are endemic to dairy contamination by that mycotoxin. Seasonal variation may be due to a lack of rainfall, that promotes the growth of aflatoxigenic fungi in the crops of raw materials, which will be used for feedstuff intended for dairy cattle, thus, the consumption of contaminated food will cause the temporary increase of AFM1 in milk and their derivatives.

STATE AND TRENDS OF THE DEVELOPMENT OF COMPETITIVE SHEEP BREEDING IN UKRAINE

The article analyzes and summarizes data of the State Statistics Service of Ukraine for 2019 and on October 1st, 2020, information from the FAO and literature sources on sheep breeding development. The research results show that lamb and goat production increased by 33.3% at agricultural enterprises in 2019. Whole meat production decreased by 2.79% during the study period in farms of all categories. The regions that obtain the most significant wool quantity are Odesa (637 tons), Zakarpattia (159 tons), and Mykolayiv (99 tons). Wool production decreased significantly in Vinnytsia and Kirovohrad (by 50%), Kyiv (by 28.6%), and Kherson (by 25.3%) regions. In January-September 2020, entire wool production decreased by 12.5% in farms of all ownership forms compared to the previous year. In 2019 wool clip per sheep decreased by 3.7% and was in the range of 0.2-3.9 kg (average 2.6 kg). According to this indicator, the first place in Ukraine takes the Kherson region (3.9 kg), the second – Nikolaev (3.7 kg), and the third – Odesa (3.4 kg). In 2018, Ukrainian enterprises produced 18,1 thousand tonnes of sheep's milk (according to FAO data), which exceeds the previous year by 6,63%. The decrease in lamb and wool production is due to a decrease in sheep stock's total number in farms of all ownership forms. In 2019 the number decreased by 5.68%, including – 7.94% in agricultural enterprises and 4.94% – in households (the difference with data on January 1st, 2020. and 2019). Ukraine established separate high-tech modular-type farms in the meat-wool (Lviv region) and meat (Dnipropetrovsk region) areas of productivity, also farms for the production and in-depth processing of sheep's milk into soft and hard delicatessen cheeses and butter (Khmelnitsky, Chernivtsi and Kyiv regions).

Разработка новых технологий: 1 Контроль протеолитических процессов при созревании твердо- го сыра с высокой температурой второго нагревания

Разработка новых технологий: 1 Контроль протеолитических процессов при созревании твердо- го сыра с высокой температурой второго нагревания

Biogenic Amines in the Different Types of Cheese

The aim of the experiment was to analyse the content of biogenic amines (BA) in the main groups of commercially produced cheeses and in cheese matured under standard conditions. The content of biogenic amines in commercially produced cheeses was monitored on the last day of consumption, and on the 1st, 30th and 60th days after production in the cheese matured under standard conditions. The highest content of biogenic amines was found in semi- hard cheeses, mainly in Eidam slices (tyramine123.12 mg.kg-1 putrescine 23.02 mg.kg-1). The cheese was not treated after the production and was cut and packed after production, which significantly affected the formation of biogenic amines. Also, “Salámový syr” - cheese had a high content of biogenic amines (tyramine 65.12 mg.kg-1 putrescine 29.25 mg.kg-1). High content of BA was also found in the other semi- hard cheeses - “Hranol neúdený” (tyramine 56.02 and putrescine 51.49 mg kg-1). In general, the content of biogenic amines in semi- hard cheeses is higher than in semi-soft, because they have a longer ripening time.

Research of heat treatment influence of milk on quality and safety of hard cheeses

The object of research is raw milk used for the production of hard cheeses by milk processing enterprises of Ukraine. The quality of raw milk is especially important, a key factor determining the effectiveness of the milk processing industry. Without milk, which meets certain requirements, it is impossible to organize the production of high-quality products. Special requirements are placed on the quality of raw milk intended for the cheese production. One of the most problematic places is improving the quality and cheese suitability of raw milk and improving the technological process for the production of natural hard cheesesDuring the study, laboratory (biochemical and microbiological) research methods are used to determine the quality indicators of raw milk and finished products, as well as their microbial contamination. And for processing the results of the study, methods of mathematical statistics are used.The work shows that bacterial contamination of raw milk, which exceeds the normative limit values, poses a threat to both the technological process of cheese making and the quality of the finished product. Methods are proposed for preventing a decrease in the yield of cheese and deterioration in its quality due to prolonged storage of milk at low temperatures. It is proved that the best results are obtained with ultra-high-temperature processing of milk with an exposure of 2–4 s. And also, that high-temperature and, especially, ultra-high-temperature (UHT treatment) is a very effective way to destroy bacterial microflora and improve the quality of raw milk by such an indicator as a «pollution tank». This allows to increase the cheese ability of raw milk. High temperatures of heat treatment of milk lead to changes in the salt and protein composition of milk. These changes should have both negative consequences – a deterioration in the rennet coagulation of milk and the synergistic properties of the clot, and a positive result consisting in an increase in the transfer of milk solids, primarily whey proteins, to clot and cheese.