| Titles |
|
English :
|
Bactericidal effect of some treatments on the quality of the produced hard cheese.
|
|
Arabic :
|
التأثير الابادى لبعض المعاملات على خواص الجبن الجاف الناتج.
|
|
| Abstract |
This study aimed at investigating some of the possible methods used in milk handling and its effect on the quality of the milk during storage as well as on the properties of the resultant Ras cheese. Some of the treatments before packaging of cheese. Were also investigated. The study included the following parts:
First Dart :- Prolongation of the shelf life of raw milk :
A- Activation of lactoperoxidase system.
The LP system was activated in cows and buffaloes milk and stored at 10 or 25°C. The results indicated that the development of titratable acidity (T.A) slowed down and clot on boiling test (COB) was negative for 12 & 48 hr at 25°C and 10°C as compared to 8 and 24 h in the control resp. All microbial groups total count, coliforms, Salmonella & Shigella (S. S) and st aphilococci decreased rapidly after 2hrs followed by a slower rate of increase than the control which increased throughout storage.
B- Cooling, thermization and Pasteurization Both thennization (at 58 & 65°C/I0 Sec) and pastelllization and storage at 7 C Caused a slow down in T.A increase and both samples were negative to the COB test for 48 hrs.
Coliforms, staph and S.S were not detected in thermized (65°) and pasteurized samples while the T. C lipolytic and proteolytic bacteria were present in small counts while in the control all microbial groups increased through 48 hr of storage.
Second Part :- Effect of milk pretreatment and storage conditions on the properties of Ras cheese.
Ras cheese was manufactured from fresh raw, therm. (65°C / 15 Sce) or pasteurized milk or raw milk stored for 24 hr or therm. milk stored for 48 hr at 7°C either as such or
followed by past. The moisture content was higher in heat treated samples and consequently other milk composition were lower. All microbial groups in heat treated samples were lower
than the control. The control and thennized milk (stored for 2 days) samples had best organoleptic properties. Therefore the latter treatment was recommended.
Third part :- Effect of some pretreatment and coating on the properties of Ras cheese.
Ras cheese was treated with Delvocid, potsorbate or dipped in hot brine before being coyered with Halaplast. It was compared with coating with plastic, wax or uncoated control.
The moisture was lower in the control and other composition higher. Moulds and yeasts were absent in the sorbate or Oelvocid samples and the latter treatment had the best organoleptic properties.
|
| Publication year |
1998
|
| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى - شارع نادى االصيد - الدقى - الجيزة
|
| Availability number |
590
|
| Organization Name |
Animal Production Research Institute (APRI)
|
| Country |
Egypt
|
| Department |
Dairy Microbiology Research Department
|
| Author(s) from ARC |
|
AGROVOC
TERMS |
Bacterial toxins.
Hard cheese.
Milk products.
|
| Publication Type |
PhD Thesis
|