Kefir characteristics are influenced by raw materials. Fresh milk and colostrum have different characteristics. In this research, colostrum was used as additional material in kefir production which could affect the chemical, microbiological, and antimicrobial properties of final the product. This study was aimed to investigate the chemical and microbiology properties of kefir prepared from milk, colostrum and milk-colostrum mixes. Kefir was prepared by adding kefir grains to 100% fresh milk, milk-colostrum mixes (20:80%; 40:60%; 60:40%; 80:20%) and 100% colostrum. Fermentation was allowed under room temperature for 24 hours. Results showed that all treatments produced kefir with relatively similar titrable acidity, free fatty acids, and fat contents. The highest levels of ethanol, total solids and protein content were observed in kefir produced from 100% colostrum. The average total microbes were 6.37-7.51 log CFU/ml; 7.04-8.23 log CFU/ml bacteria; 6.92-7.48 log CFU/ml LAB and 5.54-6.55 log CFU/ml yeast. Water activity values ranged from 0.85 to 0.89. The highest microbial and antimicrobial properties were shown by kefir produced from milk-colostrum mix of 20:80%.

This study aimed to understand the physical characteristics of cheese made of cow milk, colostrum, and milk+colostrum ripened for 20 days. Two factors in this study were cheese made of three materials: A (100% cow milk), B (50% cow milk + 50% colostrum) and C (100% colostrum), and ripening time, i.e. 0, 10, and 20 days. The process of cheese production started by heating the raw material, followed by decreasing the temperature, incorporating kefir as the starter. The next step was and the rennet and re-incubate the mixture for one hour until the fluid became solid granules, then the granules were filtered and pressed. The cheese was stored at a low temperature (4-8oC) according to each treatment. Each combination was repeated three times. The physical properties of cheese examined in this study were color, texture, pH, and microstructure. The result showed that the raw materials of cheese would produce different cheese colours in terms of lightness (L*), yellowness (b*), and whiteness index (WI) as well as cheese texture (hardness and gumminess). Also, ripening time would affect the hardness, springiness gumminess, chewiness, L*, a*, and WI of cheese. Colostrum added in cheesemaking has increased both yellowness and cavities in the microstructure.