MODIFICATION OF THE TRADITIONAL METHOD OF MAKING RAS CHEESE, AND ITS EFFECT ON THE PROPERTIES AND QUALITY OF THE RESULTANT LOW-FAT RAS CHEESE

Tohamy, M. M.; El – Nawawy, M. A.; Kandeel, A. A.; Moustafa, M. A.

doi:10.21608/jfds.2011.81848

MODIFICATION OF THE TRADITIONAL METHOD OF MAKING RAS CHEESE, AND ITS EFFECT ON THE PROPERTIES AND QUALITY OF THE RESULTANT LOW-FAT RAS CHEESE

Document Type : Original Article

Authors

¹ Dairy Sci. Dept. Fac. Of Agric. AL-Azhar Univ., Cairo, Egypt.

² Food Sci. Dept. Fac. Of Agric. Ain Shams Univ., Cairo, Egypt.

³ Diary Techn. Dept., Animal Production Research Institute,Agri-Res-Center, Egypt.

10.21608/jfds.2011.81848

Abstract

Low-fat Ras cheese (LFC) was made from cow’s milk of 1.5±0.1% fat with some modifications in the traditional method of cheese-making, including washing the curd by warm water (35C^o/5min.) or rinsing it for 5min. in the same whey (after adding 0.1 or 0.2% wt/wt sodium citrate). Full-fat cheese (FFC) being made from cow’s milk of 3 ± 0.1% fat, and low-fat cheese (without any modifications) were also made for comparison . The resultant cheeses were ripened at 8 ± 2C^o and relative humidity of 85% for 3 months. Cheese samples were analyzed when fresh and after 15,30,60 and 90 days of ripening for chemical, microbiological, rheological and sensory properties. Results indicated that as the fat content of cheese decreased, the moisture, salt and protein contents increased, whereas, the acidity, fat and protein indices decreased along the ripening period. Washing the curd by warm water decreased greatly the acidity of the resultant cheese, and this decrease consequently affected greatly the rheological and sensory properties of the resultant cheese. Microbiological properties of treated or not treated LF-cheeses were found to be lower than full-fat cheese (control), during ripening. Texture profiles of cheese showed that the LF-cheese (either treated or not) had inferior properties compared with FF-cheese, and the previous modifications of cheese-making had no effect on these properties. Sensory evaluations revealed that FF-cheese characterized with the highest properties among all treatments followed, by LF-cheese (without any modifications), sodium citrate treatments and curd washing treatments. Generally, it is worth to note that these modifications did not improve the rheological and sensory properties of the LF-cheese along the ripening period.

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