الفهرس 
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Abstract
Oat (Avena L.) is regarded as the most ancient cultivated grain; it was a staple food as early as 2000 B.C. The principal uses of oat are as feed for animals but during the last years, oat had received increased attention as a healthy cereal for human consumption, due to the high amount of dietary fiber, especially (1/3), (1/4)-β-D-glucans. Actually foods formulated with dietary fiber had been shown to lower serum cholesterol levels and postprandial blood glucose and insulin response. Oat flour can easily be incorporated into wheat-based products, including bread, cakes, biscuits and extruded snack foods. The present investigation was carried out in an attempt to clarify the nutritional assessment of two oats varieties: Common oat (Avena sativa) and Red oat (Avena byzantina) by determination chemical composition, caloric value and their content of amino acids, separation and identification of lipid fractions, fatty acids, minerals, vitamins and phenolic compounds. Furthermore, common and red oat flour were used as a good source of dietary fiber in enriched biscuits in an attempt to clarify the nutritional assessment of oats as a functional food in supplemented biscuits. Moreover, effect of the wheat biscuit supplemented with oat flours on blood lipid profile (total cholesterol, HDL- cholesterol, LDL- cholesterol, VLDL- cholesterol and triglycerides) in the experimental albino rats was investigated. The obtained data could be summarized as follows: Gross chemical composition: Gross chemical composition as well as caloric value of common and red oat was determined. The chemical composition of oat flours ranged between 9.96% - 10.47% moisture , 11.61% -13.62% Crude protein , 7.23% -8.92% Crude fat, 3.535% - 5.875%, Crude fiber , 2% -2.15% Ash, and 69.43% - 75.62% Carbohydrates. Besides, the caloric values of oat flours were 412.5 and 414.01 Kcal /100 g for both red and common oat. Amino acids composition In the present study the essential amino acids of common and red oat were determined; and the study indicated that leucine was the highest essential amino acid, followed by phenylalanine. In general, the total essential amino acids were 32.78 and 34.13 g/100g protein for red and common oat. The data revealed that levels of Leucine, phenylalanine and valine were higher than that recommended by FAO for school child and adult, while lysine, methionine and tryptophan were lower than FAO recommendations for school child and adult. The present study revealed that, methionine was the first limiting amino acid in red oat, while threonine was the first limiting amino acid in common oat compared with whole egg and human milk proteins. Lipids composition. Total lipid fractions The triglycerides constituted the major percentage of total lipids and accounted for 59.18 and 49.82% of red and common oat, while the lowest component of total lipids was Sterol esters + Hydrocarbons, which accounted for 0.74 and 0.98% of red and common oat, respectively. Fatty acids composition: The total saturated fatty acids were 21.06 and 19.15%, while the total unsaturated fatty acids were 78.93 and 80.85% in red and common oats. But the saturated / unsaturated fatty acids ratio accounted to 0.26 and 0.23 for red and common oats, respectively. The unsaturated fatty acid oleic (C18:1) recorded the highest percentage of the unsaturated fatty acids (43.70 and 41.33%) in red and common oat. While palmitic acid (C16:0) recorded the highest value of saturated fatty acids in red and common oat (18.60and 16.70%). Mineral content: Data revealed that the oat flours were relatively higher in phosphorus (469.6 and 472.57), potassium (362 and 350), magnesium (112.25 and120.67), calcium (71.71and 54.70), and iron (24.21 and13.76 mg/100g), while it had lower in copper (1.20 and1.33), sodium (7.03 and5.35), zinc (3.62 and 3.44) and manganese (3.66 and 4.42 mg/100g). Besides, the red oat had higher amount from iron, calcium and potassium compared with common oat. Vitamins content: The data outlined the B-complex vitamins content (Thiamine B1, Riboflavin B2, Pyridoxine B6, cobalamin B12) and vitamin E(tocopherol) of the two studied oat varieties. It was observed that the red oat flour recorded the highest amounts of vitamins E (0.87mg/100g), B1 (0.533mg/100g), B6 (0.33mg/100g) and B12 (0.113mg/100g), while common oat flour recorded the highest amount of B2 (0.6mg/100g). Niacin (B3) was not detected in the two studied oat varieties. Phenolic compounds content of oats: The results revealed that phenolic compounds consisted of twenty- four compounds in red and common oats, with some variations in their oat varieties. The phenolic compounds of the oats were as follows: the highest phenolic compound of red oat was vanillic (14.339mg/100g), followed by pyrogallol (11.102mg/100g), P-OH-benzoic (10.785mg/100g), benzoic (8.308mg/100g) and ellagic (7.906mg/100g),while common oat was vanillic (17.212mg/100g), followed by pyrogallol (10.540mg/100g), benzoic(6.361mg/100g), ellagic (5.048mg/100g) and catechein (4.297mg/100g). ). Besides, the lowest compound of phenolic compounds was resveratrol, which accounted for 0.331mg/100g of red oat. Meanwhile, coumarin recorded the lowest phenolic compound of common oat (0.308mg/100g). Gross chemical composition and caloric value of supplemented biscuits with oat flours: Data shows that moisture increased gradually by increasing the oat level in biscuits due to the higher content of oat flour moisture as compared to wheat flour moisture. The data of this study showed that biscuits prepared by incorporating red oat flour 10%, 20%, and 30% recorded 6.61,7.21and 7.80%,protein content; respectively. In contrast, the protein content in biscuits prepared by incorporating common oat flour 10%,20%,and 30% were 6.39,6.91and 7.63%; respectively, compared with control 6.06% protein content. The crude fat content ranged from 16.70% to 18.39% for all supplemented biscuits. Fiber content in the supplemented biscuits was also found to be higher which may be due to the incorporation of oat flours. The ash content of biscuits samples with different proportion of red and common oat flour ranging from 1.33% to 1.59% was higher than the control (1.31%). The incorporation of oat flours in biscuits resulted in a decrease in the carbohydrate content to 71.31% as compared to the control with 75.74%. Data revealed that, the control had the lowest value of caloric value, while supplemented biscuits with 30% red oat flour had the highest one. . Sensory evaluation: The data observed that with the increase in the level of oat flour (red and common) in formulation, the sensory scores for color and odor of biscuits decreased. While the sensory scores for texture of biscuits was increased. Supplemented biscuits with 30 %red oat had the best texture score according to judgesʹ score (8.76), while lowest score was observed in control treatment (7.00). Results shows that, both supplemented biscuits with 10% red oat and supplemented biscuits with 10% common oat had the best overall acceptability score according judges’ score, 8.50 and 8.82. The biological experimental data: Body weight gain: There were significant differences among all the five studied groups of the experimental rats in body weight gain. Serum total cholesterol: There were significant differences between the untreated group and three studied groups at (P<0.05) in serum total cholesterol. However, means of all the three studied supplemented biscuit with oats recorded significant decrease in serum total cholesterol of the experimental rats; the highest decrease in serum total cholesterol was recorded in group (E) fed on supplemented biscuits with 30 % red oat flour. Serum triglycerides: There were significant differences between the untreated group and three studied groups of the supplemented biscuits with oat in serum triglycerides. However, control group (A) and groups (C, D and E) recorded lowest mean in serum triglycerides, the highest decrease in serum triglycerides was recorded in group (E) fed on supplemented biscuits with 30 % red oat flour, followed by group (D) fed on supplemented biscuits with 20 % red oat flour and group (C) fed on supplemented biscuits with 10 % red oat flour. .High density lipoprotein (HDL) cholesterol: There were significant differences between the untreated group and group (E) in serum HDL-cholesterol. Furthermore, group (E) recorded significant increase in serum HDL-cholesterol (81.89mg/dl) compared with the untreated group (19.19mg/dl). Low density lipoprotein (LDL) cholesterol: There were significant differences between the untreated group and the other studied groups at (P<0.05) in serum LDL-cholesterol, Furthermore, all the studied groups significantly showed lowest serum LDL-cholesterol at (P<0.05) compared with untreated group.Very low density lipoprotein (VLDL) cholesterol calculation: Means of all the three studied groups at (P<0.05) in serum VLDL-cholesterol were compared with the untreated group. On the other hand, means of groups(C, D and E) recorded significant decrease lower in serum VLDL-cholesterol compared with the untreated group. Conclusions: In conclusion it could be recommended that: Oat is considered as useful nutritional and healthful food because it is considered as an important source of protein; minerals, (especially phosphorus and potassium), phenolic compounds, vitamins E, Thiamine and Pyridoxine as well as it recorded good balanced essential amino acids composition required for human nutrition. Supplemented biscuit with oat flours proved to be a nutritious food product, which could be recommended for diabetic, hypercholesterimc and obese patients and over-weight persons due to its both soluble and insoluble dietary fiber as well as its high content of β-glucans.