الفهرس 
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Abstract
The thesis aimed to compare the nutritional quality of Nile tilapia (Oreochromis niloticus) and sand smelt (Bissaria) fish (Atherina boyeri) by evaluating the gross chemical composition, calculating the caloric value, estimating mineral elements, determining the amino acid composition, and fatty acids composition. The thesis also aimed to preparation and evaluation some high nutritional value fish products (Noodles supplemented with tilapia and sand smelt fish minces, fish nuggets, fish fingers, fish kofta, and fish snacks). Also, the thesis aimed to prepare and evaluate the previous products using gluten-free flour as high-value functional foods for Celiac disease patients (Gluten allergy patients). On the other hand, it aimed to evaluate the quality properties of some previous products during frozen storage at -18 ± 1°C for three months.The obtained result could be summarized as following:
1- There were significant differences between chemical composition of the two fishes .However, tilapia fish contained more moisture ,protein, fat contents compared to sand smelt fish while, sand smelt fish content higher ash and carbohydrate contents.
2- Tilapia fish contained 80.02 % moisture, 84.82% crude protein, 10.46% crude fat, 5.16 ash % and 0.20 % carbohydrate (dry weight basis) while, the opposite values in sand smelt fish were 79.66 , 80.14, 10.08, 9.44 and 0.34%; respectively.
3- Sand smelt fish that are consumed wholly along with the bones are a great source of calcium (67285.27mg/kg) so it is beneficial for children , pregnant, growing and lactating women due to the greater demand of calcium .
4- The dominant essential amino acids were lysine, leucine, threonine and valine in tilapia as well as sand smelt fish meat.
5- The total essential amino acids recorded 40.30 and 39.23g/100g protein in tilapia and sand smelt fish meat; respectively.
6- EAA/ N EA ratio was 0.68 and 0.65 for tilapia and sand smelt fish meat; respectively.
7- The total saturated fatty acids were 28.68 and 26.84% for tilapia and sand smelt fish; respectively and the dominant saturated fatty acid was palmitic acid (C16:0) which recorded 20.11 and 16.22% of total fatty acids in tilapia and sand smelt fish; respectively.
8- The total unsaturated fatty acids content recorded 64.82 and 60.99% of total fatty acids in tilapia and sand smelt fish; respectively.
9- Oleic fatty acid (C18:1) was the dominant unsaturated fatty acid (23.58%) followed by linoleic acid (C18:2) as 18.40% of total fatty acids in tilapia fish , while docosahexaenoic acid (DHA) was the dominant unsaturated fatty acid (19.88% of TFAs) followed by oleic fatty acid (13.23% of TFAs) in sand smelt fish.
10- As recommended by WHO,2003 the minimum PUFA/SFA ratio could be 0.4 – 0.5 in foods, however, it was 1.18 and 1.22 in tilapia and sand smelt fish ; respectively which means that tilapia and sand smelt fish are high quality in this concern.
11- The proximate chemical composition of wheat and gluten free as well as rice flours were used for preparing the studied fish products was as 11.61, 10.60 and 12.11% moisture; 14.16 , 7.46 and 9.15% crude protein, 1.43, 0.72 and 1.04% crude fat; 0.66, 0.51 and 0.74% ash and 83.74, 91.31 and 89.08% carbohydrates; respectively.
12- Nuggets, fingers, burger and kofta, are popular ready-made products in many countries which primarily made from red meat, which is linked to cardiovascular and high cholesterol in red meat have led to fish becoming an alternative source for these products.
13- Supplementation of wheat flour or gluten free flour by tilapia or sand smelt fish minces improved the nutritional quality with high acceptability of the prepared noodles.
14-Tilapia fish meat could be successfully used for preparing high acceptance nutrias fish nuggets using wheat flour for normal consumers or gluten free flour for Celiac patients
15-The prepared fish kofta contained 51.14% moisture , 34.20 % crude protein , 12.55 % crude fat , 6.55 % ash, 46.70 % carbohydrates and 436.55 K.Cal/100g energy ( On dry weight basis) so, such product could be recommended as suitable tilapia fish product which could be used by normal consumer or Celiac patient because it prepared using rice flour
16- The proximate chemical composition of the prepared sand smelt fish snacks using wheat flour or gluten free four was 8.20 and 7.63% moisture, 13.02 and 12.73% crude protein , 2.46 and 2.28% crude fat , 2.60 and 2.47% ash, 81.92 and 82.52% carbohydrates and 401.9 and 401.52 kcal /100g (On dry weight basis); respectively.
17- The prepared snacks in these study was not fried but baked to reduce the caloric values of the product especially the snacks normally consumed by children’s.
18-Generally, the prepared sand smelt fingers for normal consumers or Celiac patient contained considerable amounts of protein, fat, ash and carbohydrate as well as high caloric value .So it is found to be high value product prepared from the cheapest types of fish in Egypt.
19- Incorporation of tilapia or sand smelt fish ( especially in case of sand smelt fish) during preparation of such functional fish products ( noodles, nuggets, kofta, snacks and fingers) significantly (p<0.05) increased protein content (included all essential amino acids), fat content (with omega- 3 and omega-6 polyunsaturated fatty acids ) and ash content (with many essential minerals ) will improve the nutritional value of the prepared functional fish products for Celiac patient they suffer from nutrient deficiencies in their food.
20- Although, there are some changes in the chemical composition, chemical quality indicators, microbial quality and nutritional value, but these changes are minor during the frozen storage for fish and fishery products.
Conclusion
1- Tilapia is considered the most productive type of fish, while sand smelt (Bissaria ) is considered the cheapest type found in Egypt.
2- The chemical composition of tilapia fish meat is similar to that of sand smelt fish, but the latter is characterized by a high percentage of mineral elements.
3- Sand smelt fish are characterized by a high percentage (19.88%) of docosahexaenoic acid (DHA) fatty acid which is essential for the growth and functional development of the brain in infants as well as required for maintenance of normal brain function in adults compared to (4.75%) in tilapia fish .
4- Both tilapia and/or sand smelt fish can be used to prepare many high-value products such as noodles, nuggets, kofta, fish fingers, and snacks.
5- Incorporation of tilapia or sand smelt fish with wheat flour or gluten-free flour enables the preparation of high-value fish products for healthy people or for celiac disease patients as functional foods.