الفهرس | Only 14 pages are availabe for public view |
Abstract As the meat contains large quantities of these substances which are important for tile human and his body construction such as protein, carbohydrates, fats, vitamines, and some essential amino acids. Therefore, in the last few years there is great attension by the meat and its preparation stages beside its keeping quality. So, this work was carried out to discuss that changes occurring at stages of meat ripening. 30 random samples were collected from different butcher shops in Alexandria province where they were chilled at 4°C (homorefrigerator) and samples were examined !after 1,3,5,7 days from slaughtering for the following: I. Tests of quality control of examined meat: 1. Measurement of pH. 1. After 1 day:- The pH was ranged from 5 to 6.24 with a mean value of 5.88. - 2. After 3 days:5 sainplçs were decomposed after 3 days of slaughtering, while pH ranged from 4.54 to 6.55 with a mean value of 6.21. 3. After 5 days:- 23 samples decomposed after 5 days of slaughtering and pH ranges from 6.25 to 7.51 with a mean value of 6.71. 4. After 7 days:- 2 samples decomposed after 7 days of slaughtering with pH value ranges from 7.01 to 7.04 with a mean value of 7.03. 2. Chemical examination:Reveals that copper sulphate test, Eber’s test and lead acetate test give positive results in 5 (16.7%) samples after 3 days of slaughtering as well as in 23 (76.6%) samples after 5 days of slaughtering and in 2 (6.7%) samples after 7 days of slaughtering. II. Microbiological examination:- Shows that pseudomonas were present in all examined samples with a minimum value of 1.1 x 1O7, a maximum 1.7 x IO9 and a mean value of9.7 x i08 The identified pseudomonas species was Pseudomonas maltophilia. 111. Histological Examination:- The samples are examined by two methods: 1. Light Microscope:- - Reveals that there is gradual change of connective tissue surrounding the muscle fiber starts after 3 days of slaughtering represented by beginning of loss of connective tissue, then dissolution of connective tissue elements leading to wide interspaces between them at the 5th day of slaughtering. Fiiially after 7 1k days of slaughtering there are complete degenerative changes of connective tissue and internal contents of muscle fiber inspite of maintenance of integrity of muscle nuclei. 2. Electron Microscope:Reveals that there is gradual internal degenerative changes in these samples chilled in refrigerator at 4°C for 5 days represented by complete vaculation of mitochondria and declination of sarcotubular system and complete loss of glycogen inspik of keeping of myofilaments on their integrity. |