Abstract:
This study was carried out at Khartoum state to evaluate the effect of packing materials on the chemical composition ( Fat , Protein, Ash , Total solids , Titratable acidity ,Volatile fatty acids, Calcium, phosphorus and Potassium) and microbiology quality (Total Bacterial Count ,Yeast and mould , coliforms , Escherichia coli , Staphylococcus aureus ,Salmonella and Listeria monocytogens counts ) of white, Romi and Mozzarella cheeses. A total of 300 samples (120 samples were taken randomly from each types of cheeses with different packing materials; 20 samples in plastic and 20 samples in paper pack), except for Mozzarella cheese only one package (plastic pack) was found , were collected from three different areas (Khartoum, Khartoum North and Omdurman). The manufacture date of the collected cheese samples was defined to be at fixed date. The samples were analyzed at the laboratory of Dairy Production Department, College of Animal Production at Khartoum University, during the period from November 2016 to December 2017. The data was subjected to statistical analysis by using SPSS programme with multivariate analysis. The results showed that the packaging materials had significant difference (P <0.01) on the chemical composition of the white cheese, fat, crude protein, Total solids, titratable acidity , ash , Ca, P and K were high in plastic pack, while the (VFA) was low. The packaging materials and area were not significantly affected the total bacterial count of white cheese samples. High presence of yeast, mold, Staphylococcus aurous and Coliforms were found in white cheese samples in plastic pack, however, Escherichia coli was not detected in cheese samples. Packing materials showed significant variation (P< 0.01) in the chemical composition of Romi cheese. Fat, crude protein, total solids, VFA, ash, Ca contents was higher, while the titratable acidity, K and P contents were lower when packed in paper pack. Different area was not significantly affected the chemical comopostion of Romi cheese, except fat , titratable acidity and ash, was significantly affected (P>0.05) by the area.The packing materials and area were not significantly affected the total bacterial count of Romi cheese. High presence of yeast and molds were found in the Romi cheese samples in plastic package, while the high presence of E.coli, Staphylococcus aureus and Coliforms were found in Romi cheese samples in paper package. Area were significantly affected (P< 0.01) the total solids, volatile fatty acid and titratable acidity of Mozzarella cheese samples, however the fat, protein , ash , Ca, P and K contents were not significantly affected by the area. The area was not significantly affected the total bacterial count of Mozzarella cheese samples. Yeast, mold, Staphylococcus aurous and coliforms were found in Mozzarella cheese samples in plastic pack, hence Escherichia coli were not detected.
Salmonella and Listeria monocytogens count were not detected in all cheese samples.
