The main purpose of this research was to determine the dynamic of total nitrogen matter and protein changes during ripening period of three kinds of indigenous Bieno cheese (A, B and C) in the region of Mariovo. The three kinds of Bieno cheese were produced with different traditional technologies. The cheese samples were analyzed for total nitrogen matter and protein during ripening process in five time intervals (in curd, after ripening, after salting, at 20-th day, at 45th day). The concentration of total nitrogen matter in examined Bieno cheese samples was between 3.98±0.06% to 4.16±0.15% and the concentration of protein in examined Bieno cheese samples was between 25.48± 0.49% to 26.53±0.93%. No significant differences in total nitrogen matter and protein concentration for p<0.05 and p<0.01 were determined. Proteolysis is affected by the type and amount of enzyme, the temperature during the ripening of the cheese, the length of ripening and the activity of the enzymes. The technological process of production, in essence, greatly affects the dynamics and breakdown of proteins, which is confirmed by our research.

The health condition of the mammary gland is highly crucial for obtaining good quality colostrum. The lactoferrin (LF), as an iron-binding protein, plays a key role in the defense mechanisms of the mammary gland due to its’ bacteriostatic properties. The study aimed to investigate the factors affecting the LF concentration in the bovine colostrum milk during the postpartum period, and the effect of somatic cell count (SCC) on the LF concentration and milk composition. The cows were randomly selected at a dairy farm in Pelagonia region. Colostrum samples from 12 cows were collected. Samples were taken at different time intervals after parturition, 1, 6, 12, 24, 48, 72, 96, and 120 h after parturition. Cows in their second parity were found to have higher levels of LF compared to cows in the third and higher parity (p>0.05). Time had a significant effect on the LF concentration (p<0.01), with the highest value recorded 1 h after parturition remaining stable for one hour. LF concentration and SCC in the colostrum showed a weak positive correlation (r=0.40; p<0.01). The highest LF concentration was noticed when SCC was above 800,000 cells/mL. In conclusion, the colostrum LF concentration was significantly affected by the interactions of the two factors, i.e., time after parturition and SCC (p<0.05). Milk composition was affected by elevated SCC. Parity showed no association with LF. The SCC can be used as a reliable means of assessing colostrum quality.

In this study milk samples from Holstein Friesian cows were collected and analyzed during the first and second lactation period in a period of six months. The following parameters have been examined: protein content, fat content, lactose, and dry matter in milk. The average values of the content of milk protein, fat, lactose and dry matter in the milk of first lactation were as following: 3,14%, 3,25%, 4,46 %, 11,48% and in the milk of second lactation are: 3,21%, 3,29%, 4,39% and 11,68%.%. Milk from cows in the second lactation had a higher concentration of protein, more fat and dry matter than cow's milk from the first lactation. Keywords: quality, chemical composition, milk, lactation, breeds.

Abstract. The milk is a biological fluid with a very complex composition, yellowish white color and distinctive flavor and aroma. Dairy industry has a number of specific features that distinguish it from other agricultural sectors. The purpose of this labor was to display the influence of bactofugation on the long-life milk quality. Bactofugation process as significant mechanical process for bacterial removing without heating, are very important factors in long-life milk production. The subject of examination was a cow's milk as: raw milk immediately after receipt in the dairy and bactofugation milk. On all samples were exanimate the microbiological parameters (Coagulase positive staphylococci, Enterobacteriaceae and Aerobic mesophilic bacteria) and chemical parameters (percentage of milk fats, proteins, lactose, non-fat dry matter). The bactofugation, like device for mechanical removing of microorganisms, using a centrifugal force, allows production of quality long-life milk without further thermal treatment on it.

Experimental research describes the autochthonous traditional production of bieno cheese and its importance in conditions of globalization and industrialization in food production. The purpose of this research was to present the technology of three varieties of indigenous bieno cheeses (A, B, and C) in the Mariovo region, in the Republic of North Macedonia, and to monitor the dynamics of active and titratable acidity as important parameters in the technological process. During the research, the changes of these parameters of the three variants (A, B, and C) of cheeses in different stages of maturation were monitored (in curd, cheese after dry ripening, cheese after dry salting, the 20th day of ripening, and the 45th day of ripening). The rheological properties of the cheese are greatly influenced by the active (pH) and titratable (0SH) acidity. During the ripening of cheeses under the influence of lactic acid bacteria, the biggest changes occur in lactose, which transforms lactose into lactic acid and other organic acids that play an important role in the formation of sensory and rheological characteristics of cheeses. The displayed technological parameters are of great importance for the bieno cheeses and can serve in the direction of standardization of this cheese and its protection with a designation of origin or a geographical indication based on the source technology. Keywords: Bieno cheese, technology, active and titratable acidity.