Estimation of the Quality of some Fermented Dairy Products in Cairo and Giza Governorates

Abstract

A total of twenty samples of different types of Zabady and Raybe milk were collected from local markets in Cairo and Al-Giza governorates and stored in the refrigerator at 5±1°C. Microbiological, physicochemical, and rheological properties of collected samples were studied at the beginning, middle, and end of storage period. The results showed that the average values of acidity, pH, Viscosity, Syneresis, Water Holding Capacity (WHC%) and Radical Scavenging Activity (RSA%) of fresh samples ranged from 0.72±0.02 to 0.82±0.04%, 4.52±0.05 -4.61±0.02, 3393±7.00 -8535±9.00 cP, 2.70±0.04 -3.88±0.07 (ml/5g), 20.70±0.18 -45.92±0.19% and 14.69±0.13 -21.62±0.12%, respectively. The collected fresh samples contained 11.25±0.15 -14.86±0.19 % total solids. Microbiological analysis revealed that the collected fresh samples contained 7.95 to 8.52 (log cfu/g) lactic acid bacteria, 2.16 to 2.62 (log cfu/g) Coliform Bacteria and 2.25 to 2.33 (log cfu/g) Yeasts and Molds. The hardiness and gumminess of the high-fat traditional zabady samples were higher than the rest of the zabady samples, while the springiness, cohesiveness, and chewiness in the industrial zabady samples were higher than the traditional zabady. As the storage period progressed, chemical, physical, microbiological, and rheological changes occurred.