- National Agrarian University of Armenia, 74, Teryan Str., Yerevan 0009, Armenia
- Open Access funded by Agricultural University of Georgia
- Under a Creative Commons license
Research has been conducted in Lusadzor community of Tavoush province in Armenia to determine the processability of milk samples collected from Jersey and Simmental cows for cheese manufacturing. The chemical composition as well as physical–chemical and technological parameters of the milk samples have been analyzed experimentally. In addition, the researchers estimated physical, chemical and organoleptic parameters as well as the yield of the cheese produced from the bulk milk collected from Jersey and Simmental cows. The results of the research proved that the milk samples collected from Jersey and Simmental cows possess the necessary physical–chemical and technological properties and can be used as high-quality raw material for manufacturing brine-ripened (pickled) cheese. The highest content of dry matter, observed in the milk collected from Jersey cows, stemmed from the high contents of fat, protein and minerals. The content of lactose (milk sugar) and physical characteristics (density, freezing temperature) did not vary significantly across the samples. The rennet clots formed in the milk collected from Jersey cows were characterized by higher structural–mechanical parameters and syneresis. Jersey milk possesses the qualitative characteristics that best contribute to high cheese yield, which allows for the most efficient cheese production. Cheese manufactured from Jersey milk is distinguished by less water content, higher fat and protein contents and higher organoleptic indicators, which all together improve the quality of cheese turning it into a highly competitive product.
- Breed of the cows;
- Cheese-making properties of milk;
- Yield of cheese;
- Organoleptic parameters
Cheese is a highly-nutritious and biologically adequate foodstuff traditionally consumed by the population of the Republic of Armenia as part of the daily ration. Within the commodity pattern of the country's retail turnover, the turnover of cheese is nearly equal to the total turnover of other dairy products (as of 2008–2012, 0.3–0.7 and 0.5–0.8% respectively) .
Cheese manufacturing is a coupled process of concentration and biological transformation of the milk components into gustatory and aromatic compounds that determine the unique characteristics of the particular cheese. Use of high-quality raw materials that provide for effectiveness of physical–chemical processes and fermentation all along the cheese making and ripening periods is the key factor in manufacturing cheese with more intense flavor, rubbery and even texture.
The key factors that determine the cheese yield are as follows: milk fat and casein contents; quantities of the milk constituents (especially fat and casein) lost during the process of cheese-making; water content in cheese. The breed of cattle has particular effect on the cheese-making characteristics of milk, as milk produced by different breeds of cow differs in composition and some of its properties  and .
The increasing importance of high-protein food products necessitates well-targeted selective breeding for desirable characteristics that contribute to increased economic efficiency of the industry. For the foregoing reasons, our research focused on evaluating the quality of milk collected from purebred Simmental and Jersey cows in Armenia as well as the quality of dairy products produced from that milk.
Research data and methodology
From February through September 2015, milk was collected from Jersey (n = 20) and Simmental (n = 20) cows on the dairy farm of “Himnatavoush” Development Foundation (Lusadzor village of Tavoush province) to examine its physical–chemical and technological (cheesemaking) characteristics. The bulk milk collected from the animals of the same breed was used for production of cheese.
Both tasks, namely the analysis of the physical–chemical and technological characteristics of the milk and cheese and production of cheese, were accomplished at the Department of Animal Product Processing Technology of National Agrarian University of Armenia. The researchers used generally accepted standard research methods. The fat and nonfat milk solids (SNF) weight ratios in milk were measured using an EKOMILK-98 Ultrasonic Milk Analyzer; The Gerber method was used to determine the fat weight fraction in cheese (ГОСТ1-3624-67). To measure the protein and casein contents in milk, the researchers used the Formol Titration Method. The density of the milk was measured by using areometer (ГОСТ-3625-71). The dry matter content was measured by drying the samples in an oven at 102 ± 2 °С (ГОСТ-3626-73). To determine the content of minerals, the researchers used the ashing technique, which is based on ignition of samples in an ash muffle at 700 °С. The organoleptic characteristics of the cheese were graded on a 100-point scale (ГОСТ-7616-55) . The milk coagulating property was obtained by the rennet test (by Z. H. Dilanyan), while the rennet curd tension was measured by means of the Meshcheryakov's device . Syneresis was determined by drainage test, based on the quantity of whey separated within a period of thirty minutes from a rennet clot cut in four pieces.
Analysis of the physical–chemical properties of the milk collected from Jersey and Simmental cows reveals that the protein and fat contents in the milk produced by Jersey cows are higher by 0.6%, and 1.23% respectively. Also, the weight content of casein is different. Jersey milk is the richest in casein content. It contains 0.55% more casein than the milk of Simmental cows (Table 1).