الفهرس 
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Abstract
Almost all byproducts are a rich source of trace elements, whose levels/amounts are usually much higher in byproducts such as offal than in muscular tissues. Furthermore, the demand for offal is likely to increase with the rapidly growing population, as it can be commercially sold for human and animal nutrition and is economically advantageous (e.g., high profitability). Therefore, further research into consumer perception of offal consumption is needed, as well as investigations of the potential use of the nutrients contained in offal. Such studies will ensure a comprehensive presentation of the factors that affect the demand for offal.
This study was designed to determine and enrich the nutritive values data of the edible beef offal and also to evaluate the public health importance of the offal.
A total number of 120 samples of different types of common edible beef by-products (20 of each of liver, kidney, heart, lung, spleen, and intestine) were collected from main local slaughterhouse at Kharga city at New Valley Governorate, Egypt.
The samples were subjected to a proximate analysis (moisture, protein, fat, and ash); calculation of total energy; calculation of carbohydrates contents, percentage of calories from each of protein, fat and carbohydrate; and determination of cholesterol content.
Proximate composition:
Concerning the moisture content (%), was as maximum of 74.36, 78,30, 78.37, 78.37, 80.12, and 83.20; minimum of 69.06, 74.15, 73.56, 73.22, 75.12, and 78.10 and average as 71.77, 76.26, 75.22, 76.13, 78.06, and 80.42 for liver, kidney, heart, spleen, lung, and intestine respectively. Intestine showed the highest (P<0.05) moisture content, while liver showed the lowest value.
As for protein content, the achieved results indicated that the minimum, maximum and mean values of liver were 18.80, 23.66, and 21.70±0.27 respectively, while kidney results were 17.66, 22.30 and 19.67±0.23. In heart which were 17.9, 21.9 and 20.15±0.26, while spleen results were 18.1, 22.8 and 19.77±0.28. In lung results were 12.20, 19.8 and 16.98±0.45, where intestine results were 10.30, 18 and 14.76±0.54, respectively.
Highest protein percentage (P<0.05) recorded in liver; however, intestine showed the lowest percentage.
With concern to the fat content, the minimum values were 2.32, 1.29, 2.01, 0.70, 1.12, and 1.02, while maximum results were 5.25, 3.60, 4.09, 3.90, 3.15, and 2.24; while average values were3.72±0.16, 2.33±0.15, 3.01±0.15, 2.01±0.16, 2.28±0.11 and 2.24±0.14 in liver, kidney, heart, spleen, lung and intestine respectively. Highest fat content (P<0.05) was recorded in liver, while lowest was recorded in spleen.
Regarding the achieved ash analysis, results in liver were 1.10, 1.65 and 1.35±0.03 respectively, while kidney results were 0.99, 1.66 and 1.35±0.04 respectively, in beef heart results were 0.92, 1.30, and 1.01±0.01, while spleen results were 0.94, 1.62, and 1.25±0.04; while lung results were 0.87, 1.33 and 1.05±0.02, where intestine results were 0.81, 1.10 and 0.94±0.01.
Highest ash value (P<0.05) obtained of ash was in kidney, while lowest was in intestine.
The achieved results of carbohydrate content (%) declared that the minimum, maximum and mean values of liver, kidney and heart samples were 0.37, 5.80 and 2.051±0.360; 0.03, 2.34 and 1.025±0.166; 0.06, 3.69 and 0.787±0.191 respectively, while in spleen, lung and intestine samples were 0.04, 4.76 and 1.037±0.272; 0.12, 7.86 and 2.273±0.488; 0.10, 7.5, 2.100±0.449 respectively.
Highest carbohydrates value was recorded in both lung and intestine, while the lowest was recorded in kidney.
Mineral Content:
The results obtained for calcium were 6.17, 7.93, 2.50, 6.23, 8.22 and 0.53 as minimum, 11.38, 14.71, 12.43, 11.42, 15.21 and 7.95 as maximum levels; average levels were 8.65±0.33, 10.87±0.42, 5.31±0.51, 8.56±0.26, 11.45±0.39, and 4.47±0.35 in liver, kidney, heart, spleen, lung and intestine respectively.
Highest calcium level (P<0.05) was recorded in kidney and lung, while lowest was recorded in intestine.
Regarding to the iron content, results declared for average values in liver, kidney, heart, spleen, lung and intestine 10.24±0.75, 8.75±0.4671, 5.21±0.3116, 39.12±0.89, 6.35±0.20, and 1.75±0.25, respectively. Minimum values were 5.74, 5.37, 1.28, 32.41, 5.05, and 0.35; maximum results were 19.65, 12.70, 5.21, 39.12, 6.35, and 1.75 for liver, kidney, heart, spleen, lung and intestine respectively.
Highest iron content was recorded in spleen, while lowest was recorded in intestine. Concerning the phosphorus content in beef offal, the achieved results showed minimum values obtained were 317.5, 200.6, 194, 236.6, 180.7 and 94.5, while maximum levels were 422.3, 238.3, 255.9, 284.6, 220.5 and 110.5, and mean values were 369.2±5.05, 217.6±2.84, 211±1.68, 260.6±2.85, 208.8±2.35, and 103.6±1.01 in liver, kidney, heart, spleen, lung and intestine respectively.
Highest content from phosphorus (P<0.05) was recorded in liver, while lowest was recorded in intestine.
Public Health Importance:
Calories content:
The gross energy content results declared that mean energy values (Kcal/100gm) were 126.1±1.60, 101.2±1.55, 110.1±1.49, 100.5±1.54, 95.01±1.44 and 85.83±1.74, while minimum values were 116.5, 91.07, 92.78, 90.74, 86.3, and 69.20, while maximum levels were 141.8, 114.9, 120.4 115.3, 107, and 98.7 in liver, kidney, heart, spleen, lung and intestine respectively.
Highest mean energy level (P<0.05) was recorded in liver, while lowest was recorded in intestine.
For calories percent from protein, the minimum values were60.24, 71.18, 63.43, 69.01, 49.16, and 53.06; the maximum values were 77.02, 86.96, 80.38, 88.66, 86.32, and 82.51; and mean values were 68.97±1.02, 77.96±1.08, 73.37±1.18, 78.89±1.33, 71.70±2.05, and 68.63±1.84 in liver, kidney, heart, spleen, lung and intestine respectively.
The highest values of calories derived from protein showed in spleen and kidney, where lowest value was in intestine.
Regarding calories percent from fat, the minimum values were16.99, 11.32, 17.56, 6.94, 11.52, and 12.63; the maximum values were33.33, 28.36, 33.32, 30.43, 27.82, and 35.42; while average values were26.52±1.0, 20.52±1.13, 24.45±1.04, 17.80±1.31, 21.61±1.0, and 23.36±1.29 in liver, kidney, heart, spleen, lung and intestine, respectively.
Highest value of calories percent derived from fat was in liver then intestine, while the lowest value was in spleen.
With concern to calories percent from carbohydrates, it was generally low showing minimums of 0.24, 0.16, 0.10, 0.25, 0.35, and 0.59; while maximums were 12.96, 3.81, 8.85, 12.74, 25.38 and 32.37; and average values were 4.51±0.79, 1.51±0.24, 2.17±0.43, 3.31±0.64, 6.69±1.61, and 8.0±1.87 in liver, kidney, heart, spleen, lung and intestine, respectively.
Highest value of the calories percent derived from carbohydrates was in intestine, while the lowest was in kidney.
Cholesterol content of beef offal
The results obtained for cholesterol in examined samples show that mean values obtained from liver, kidney, heart, spleen, lung and intestine were 303.4±5.09, 350.3±8.61, 141.5±3.21, 258.4±5.26, 236.1±7.57 and 114.7±7.39 respectively.
Minimum values were 274.4, 249.0, 112.2, 218.0, 184.9, and 74.80; while maximum values were 364.7, 398.3, 167.8, 298.0, 345.3, and 74.80 in liver, kidney, heart, spleen, lung and intestine respectively.
Highest cholesterol level (P˂0.05) recorded in kidney, while lowest was recorded in intestine.
The result obtained in the present study indicated that edible beef offal contains a precious level of nutritive values that is more and readily absorbable and also a relatively cheaper source of protein with significant levels of minerals, where also showing no public health hazards under normal recommended daily levels.