Production of brined soft cheese from frozen ultrafiltered sheepʹs milk. Part 2 compositional, physicochemical, microbiological and organoleptic properties of cheese

Skimmed milk was concentrated by ultrafiltration (UF) to 19.37, 23.40 or 26.49% total solids (TS), mixed with cream to prepare recombined UF concentrates (R-UFCS) with 30.40, 33.95 or 36.90% TS, respectively, and then frozen and stored at −20 °C. After 2, 4 and 6 months frozen storage, the concentrates were fast-thawed and used directly for making brined soft cheese generally following the traditional procedure of Feta cheese. The compositional, physico-chemical, microbiological and organoleptic properties of UF cheeses were compared with those of control Feta cheese. The UF cheeses had similar pH, higher protein and calcium, but lower fat, moisture and yield values than the control cheese. The UF cheeses underwent greater proteolysis, but less lipolysis than the control cheese. The UF cheeses had a sandy texture, received lower scores for appearance, were harder and more acidic in flavour, and ranked lower in overall quality than the control cheese. The higher calcium content was apparently responsible for the sandy texture and the lower overall quality of the UF cheeses. Because of the inferior quality of the UF cheeses and the lack of a significant increase in yield, the production of brined soft cheese from frozen concentrated by UF sheepʹs milk does not seem to be commercially applicable.