الفهرس 
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Abstract
Ostrich is a wonderful healthy red meat with all the hearty flavor of beef, extremely high in protein, low in fat, calories, cholesterol but high in Iron.
The present study was carried out to determine the physicochemical and nutritive quality of ostrich meat slaughtered in Egypt. A total of75 samples were collected from the thigh(m. iliotibialis lateralis), back (m. obturatorius medialis) and the leg (m. gastrocnemius pars externa)(25 each) of ostrich carcasses slaughtered at Assiut and Cairo Governorates. The samples were transferred to the laboratory under refrigerated condition in an ice tank where they were left in the refrigerator for 24 - 48hrs, then prepared for physical and chemical analysis. The samples were evaluated from sensory point of view. The pH value, water holding capacity, hydroxyproline, collagen and connective tissue contents, as well as proximate composition (moisture, dry matter, protein, fat and ash).Cholesterol, phosphorus, calcium, potassium and iron contents were also estimated. In addition, carbohydrate, and gross energy contents were calculated.
The sensory evaluation revealed that:
Thecolor scores of the ostrich meat sample varied from 8.25 to 9 with mean value 8.88 ± 0.05, 8.66 to 9 with mean value 8.93 ± 0.02, and from 8 to 9 with mean value 8.62 ± 0.06 for thigh (m. iliotibialis lateralis), back (m. obturatorius medalis), and leg (m.gastrocnemius), respectively.
The odor (aroma) scores of the ostrich meat sample ranged from 8.25 to 8.5 with mean value 8.45 ± 0.02, 8.33 to 8.66 with mean value 8.43 ± 0.03, and from 8.7 to 9 with mean value 8.86 ± 0.03 for thigh, back, and leg, respectively.
Flavor scoresvaried from 7.25 to 8.75 with mean value 8.2 ± 0.1, 7.66 to 8.33 with mean value 8.2 ± 0.05,and from 7.3 to 8 with mean value 7.74 ± 0.03 for thigh, back, and leg, respectively.
The tenderness scores of the cooked ostrich meat sample, varied from 8 to 8.75 with mean value 8.46 ± 0.06, 7.66 to 8.66 with mean value 8.38 ±0.09, and from 7.77 to 8 with mean values 7.92 ± 0.03 for thigh, back, and leg, respectively.
Theoverall acceptance scores ranged from 7.5 to 8.75 with mean value 8.4 ± 0.09, 8.33 to 9 with mean value 8.71 ± 0.06, and from 7.7 to 8.3 with mean value 8.15 ± 0.05 for thigh, back, and leg, respectively.
pH values ranged from 5.70 to 6.27, 5.77 to 6.19, and 5.67 to 6.39 with mean values 5.97 ± 0.03, 5.94 ± 0.02, and 6.07 ± 0.03 formusclesiliotibialis lateralis, obturatorius medalisandgastrocnemius, respectively.
Water holding capacityranged from 8.33 to 17.74, 11.83 to 25.66, and from 12.00 to 21.32 with mean values 14.17 ± 0.49, 17.23 ± 0.85, and 16.03 ± 0.55%,respectively.
Hydroxyproline contents ranged from 0.31to 0.65, 0.21 to 0.59, andfrom 0.21 to 0.49 with mean valuesof 0.53 ± 0.02, 0.43 ± 0.02,and 0.33 ± 0.01%;collagencontent from 2.50 to 5.21,1.66 to 4.71, and from 1.66 to 3.95 % with mean value 4.26± 0.15, 3.47 ± 0.15,and 2.60 ± 0.11%, and connective tissue contents from 11.27 to 23.03, 7.5 to 22.91, and from 7.98 to 18.40with mean values 18.80 ±0.62,16.32 ± 0.79 and 12.15± 0.51 formusclesiliotibialis lateralis, obturatorius medalisandgastrocnemius, respectively.
Hydroxyproline, collagen and connective tissue contents showed significant difference between the three studied muscles with m.iliotibialis lateralis recorded the highest mean value (P <0.05).
Moisture content was in the range of 72.67 - 75.92,74.65 - 77.67,and 74.87 - 76.83 with means of 74.88± 0.16, 76.10± 0.20, and 76.33± 0.09 %; whiledry matter was in the rangeof 24.08 - 27.33,21.72 - 25.35and23.17 - 25.13 with means of 25.12 ± 0.17, 23.70 ± 0.26 and23.67± 0.09%;and protein was in the range of 21.81 - 24.81, 20.11 - 23.09 and 20.67 - 22.58 with means of 22.68± 0.16, 21.35± 0.20, and 21.37± 0.07%,respectively, formusclesiliotibialis lateralis, obturatorius medalis, andgastrocnemius.
In addition, the fat content of ostrich meat was in the range of 0.70 - 1.66, 0.60 - 1.95, and 0.76 - 1.90 with means 1.18± 0.05, 1.29± 0.06, and 1.20 ± 0.05; ash in the range of 1.04 - 1.70,0.90 - 1.60,and 0.74 - 1.28 with means1.26 ± 0.03, 1.20 ± 0.04and 1.06 ± 0.03%; and carbohydrates in the range of 0 - 0.25, 0 - 0.28, and 0 - 0.17 with means0.06 ± 0.02, 0.05 ± 0.02, and 0.05 ± 0.01%formusclesiliotibialis lateralis, obturatorius medalis, andgastrocnemius.
The minimum, maximum and mean values of gross energy(Kcal/100gm) content were 95.64, 110.9, and101.3± 0.73form.iliotibialis lateralis; 89.44, 107.2, and 97.03± 0.93 for m.obturatorius medalis; and 92.20, 107.4,and96.25± 0.67for m. gastrocnemius, respectively.
The percentageof energyderived from fat ranged from 6.40 to 16.23with mean10.57± 0.45;from 5.83 to 16.52with mean11.97± 0.49; and from 7.35 to 15.92with mean11.12± 0.42formusclesiliotibialis lateralis, obturatorius medalis,andgastrocnemius,respectively.
However, the energypercentagederived from protein ranged from83.77 to 93.60 with mean89.43± 0.45;from 83.48 to 94.17 with mean88.03± 0.49;and from84.08 to 92.65 with mean88.88± 0.42; and that derived from carbohydrateranged from 0 to 0.99 with mean0.24 ± 0.06;from 0 to 1.14 with mean0.20 ± 0.06; and from 0 to 0.71with mean 0.21 ± 0.05 for musclesiliotibialis lateralis, obturatorius medalis,andgastrocnemius,respectively.
Forcholesterol,the previous values (mg/100g) were 30.14, 45.36and 38.16 ± 0.97 form.iliotibialis lateralis; 31.05, 68.00,and 41.72 ± 1.65for m.obturatorius medalis; and 31.88, 54.33, and 41.10 ± 1.17for m. gastrocnemius.
The phosphate, calcium and iron levels were detected in 20 of each of musclesiliotibialis lateralis, obturatorius medalisandgastrocnemius.
The phosphate levels (mg/100gm) in the examined muscles samples were in the range of 245.5 - 329.8 with mean value 284.3 ± 5.72 for m.iliotibialis lateralis; the range of 210 - 303.3 with mean value 242.9 ± 4.61 for m. obturatorius medalis; and the range of 193.9 - 267.8 with mean value 228.7 ± 4.30 for m. gastrocnemius.
As for calcium levels (mg/100gm) ranged from 5.4 to 14.9 with mean value 11.01 ± 0.80; from 7.17 to 17.2 with mean value 12.05 ± 0.70; and from 5.6 to 16.2 with mean value 10.03 ± 0.54formusclesiliotibialis lateralis, obturatorius medalisandgastrocnemius,respectively.
Regarding iron content (mg/100gm), the minimum, maximum and mean values were 2.17, 5, and 3.28 ± 0.18 for m.iliotibialis lateralis; 2.4, 6.2, and 4.61 ± 0.21 for m. obturatorius medalis; and 1.8, 5.4, and 3.08 ± 0.19 for m. gastrocnemius, respectively.
The potassium contents were detected in 16 of each of musclesiliotibialis lateralis, obturatorius medalis,andgastrocnemius.
The potassium levels (mg/100gm) were in the range of 210.5 - 375.7 with mean value 274.7 ± 11.86 for m.iliotibialis lateralis; 250.1 - 333.4 with mean value 278.8 ± 5.38 for m. obturatorius medalis; and of 221.2 - 342.0 with mean value 267.1 ± 8.74form. gastrocnemius.
The statistical analysis of the results showed the presence of significant difference (P <0.05) between some of the mean values of the analyzed muscles samples, while of some others there wereno significant difference (P > 0.05), regarding pH values, WHC, moisture, dry matter, protein, ash, gross energy, phosphate, and iron contents.No significant difference (P > 0.05) was found, however between the mean values of the studied muscles, regarding fat, carbohydrates, cholesterol, potassiumand calcium contents.