Determination of coagulation and chemical characteristics of UF-Feta cheese made from retentate powder in different levels of fat and CaCl2

In this research، the effects of different levels of retentate fat (0، 2، 6، 10، 14 and 18%) and CaCl2 (0 and 0. 02%)، on the coagulation (coagulation time، whey amount and yield) and chemical characteristics (fat، total solids، acidity and pH) of UF-Feta cheese made from retentate powder were studied. Furthermore، the effects of salting manner (addition on special paper after coagulation or direct addition to retentate)، on the coagulation and chemical characteristics of full-fat sample were investigated. The statistical analysis showed that، the coagulation time and whey amount were increased with fat reduction، whereas the yield was decreased significantly (p < 0. 05). Adding CaCl2 had significant (p < 0. 001) reducing effect on coagulation time and this effect was more observable in cheese samples with fat levels lower than 10%. The effects of CaCl2 on whey amount، yield and chemical properties were insignificant. On the other hand، fat reduction had significant effect on all the chemical properties. Maximum fat content، total solids and acidity; and minimum pH were observed in cheese sample that made of 18% fat retentate so that، differences with other treatments were significant (p < 0. 05). The addition of salt directly to retentate (without using of special paper) decreased the total solids and whey amount and increased yield، but pH and acidity didn’t show significant differences.