Ripening changes in Cephalotyre ‘Ras’ cheese slurries

Abstract

Cephalotyre (Ras) cheese slurries developed within 7 d of storage at 30 °C a flavour similar to that of conventional Ras cheese ripened for 2 months. Addition of a proteinase/lipase mixture, trace elements or Na citrate to fresh cheese slurries before storage at 30 °C enhanced flavour development. Additive-treated slurries showed after storage for 5 d at 30 °C a strong flavour similar to that of 3-4 months Ras cheese with increased protein degradation, acidity development, volatile fatty acid formation and higher bacterial counts. The effectiveness of the additives in enhancing flavour development and related chemical changes was in the order: proteinase/lipase mixture > trace elements > Na citrate.The conventional long-time curing process for ripening of cheese is still the prevailing custom. Cephalotyre ' Ras', known as Ras cheese, is the national hard type in Egypt. This cheese is normally marketed after a ripening period of 4 months. This period gives a fully ripened product with a pungent flavour, close to that of Kachkaval cheese.An urgent need exists for manufacturing and curing techniques which will both accelerate and provide control over the development of full flavour in the cheese. Kristoffersen et al. (1967) developed a process of accelerating flavour development in Cheddar cheese curd in which 24-h-old salted unpressed Cheddar curd was blended with 5-2% NaCl solution and the homogeneous slurry stored at 30 °C. The slurries containing about 40 % total solids developed a strong flavour in days rather than in months. The same authors reported that the liquid cheese product would appear to be ideally suited for making spray-dried cheese powder, heat and cold processed cheese, and cheese-containing bakery goods.Rapidly ripened cheese slurries have been used by some investigators in the processing of dairy products. Sutherland (1975) showed that it was possible to replace the matured cheese components in processed cheese with ripened cheese slurries, and Dulley (1976) recommended the use of ripened cheese slurries to accelerate the ripening of Cheddar cheese.The present work was carried out to provide information on the properties of slurried Ras cheese curd as affected by its incubation at 30 °C for several days. The effect of incorporating into the fresh slurries proteinase/lipase, trace elements or Na citrate prior to incubation at 30 °C was also investigated.

Mechanisms of incorporation and release of enzymes into cheese during ripening

“…Acceleration of cheese ripening without an increase in proteolysis occurred, but off-flavours developed. A similar approach was used by Abd El Baky, El Neshewy, Rabie, and Farahat (1982) to accelerate Cephalotyre ''Ras'' cheese. Proteolytic, lipolytic and bacteriological properties increased flavour without defects.…”