Manufacture and quality of UF Ras cheese

Abstract

Ras cheese was made by means of the traditional method from cow's milk and milk concentrated hy ultrafiltration to concentration factors 2 and 5, and from diafiltered x5 retentate. The fresh cheese yield was detcrmined and cheese was ripened for 3 months, changes in moisture, fiat, nitrogen fractions, pH, acidity and ripening indices were followed periodically during the ripening period. The organoleptic propcrties of the cheese were also assessed. UF Milk retentate gave higher cheese yield depending on concentration factor. UF Ras cheese from high concentrated retentate was characterized hy slow protein degradation, flavour dcvclopmcnt and hard texture. The composition and properties of UF Ras cheese from x2 retentate were close to that of traditional Ras checse.

Effect of Adding Microbial Lipase on the Acceleration of Uf-Ras Cheese Ripening

“…One batch of cheeses was used to produce UF-Ras cheese without enzyme addition (as Control), while the other three batches were separately mixed with microbial lipase prior coagulation at a ratio 50.000, 100.000, 150.000 U/15 kg of retentate, respectively. Coagulation by rennet addition (2 g/100 kg) and the procedure of cheese making was followed as described by El-Shibiny et al (1991). Cheese ripening took place at 12ºC and a relative humidity of 90-95% for 90 days.…”

“…Cheese samples were evaluated for flavour, body and texture by the staff members at Dairy Department, Agricultural Faculty of Fayoum University according to the scoring sheet of El-Shibiny et al, (1991).…”

“…Ras cheese produced by ultrafiltration has many advantages on the economical, technological and nutritional levels. On the other hand, UF-Ras cheese was characterized by slower ripening, hard texture and lack of flavor than traditional ones (El-Shibiny et al, 1991). In order to take the advantage of ultrafiltration in Ras cheese manufacture, it is indispensable to accelerate the ripening process and reactions included which reflect on the flavor and texture of the resultant cheese.…”