الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Cheese is one of the important source of protein indiet and have high nutritive value. In fact, during cheese ripening, degradation of casein occurs leading to the accumulation of free amino acids that can be converted into biogenic amines by the activity of bacterial decarboxylases, Biogenic amines are important nitrogen compounds of biological activity They can be detected in both raw and processed foods. In food some types of microbiology contain have related to spoilage and fermentation processes. The main biogenic amines in food are the aromatic, tyramine, histamine, β-phenylethylamine andTryptamine, and the aliphatic putrescine and cadaverine, and polyamine, agmatine.Biogenic amines are biologically active amines which have important physiological effects in humans, generally either psychoactive or vasoactive. in Egypt,the studies that evaluate the contain of biogenic amines in foods are rare,the Egyptian food industry unfortunately not interested of the level of biogenic amines on its product, andunlicensed factor produce a lot of product that didn’t have censorship,food like cheeses consumption on a widely range and have a high nutritive value, it was important for public health to make a survey onits different cheeses types to determinethe (BAS) levelin cheeses to know the current situation ofit ratio in cheeses and its effect on the health of community.The Study design is Cross-sectional design .the sample size was 30 samples,Five types of cheese will be targeted in this study which are: (Ras –Demietta - Cheddar- Blue cheese- Gouda(. .6 samples of each type will be randomly collected from the dentical dairy retailers in Alexandria market.
All cheeses samples were analyzed for the following test:
1- To assess the proximate chemical analysis of cheeses:moisture, total solids, protein, fat, ash, NaCl and pH
2- To detect the levels of some of biogenic amines (histamine, tyramine, putersine and β-phenylethylamine ) in cheeses.
3- To determine the levels of free amino acids in the sampled cheese.
from our results, the following can be concluded:
1. Thechemical composition of traditional cheese shows nearly or higher level of the Egyptian reference while The nontraditional cheese show nearly composition to the international reference and some of it showed nearly composition to Egyptian reference except fat and moisturewas lower in both.
2. Ras cheeses have the highest mean percent of total solid(70.2% ) and protein (31.92) whileDomiati cheeses was the lowest cheeses in bothof total solid(46.2)and protein (15.80).
3. Domiati cheeses have the highest mean percent of moisture content (53.7) and NaCl (5.483) while thelowest cheesewasRas cheeses in moisture (29.5).and Gouda cheesesin NaCl (1.796)
4. On other hand The Blue cheese cheeses have the highest men percent of fat (27.66) and the lowest was inDomiati cheese(12.48).
5. Gouda cheeses have the highest mean percent of both pH(5.50) and ash (3.3) whileDomiati cheese was the lowest in pH( 5.09) andAsh (2.2).
6. The amino acidtyrosinethe precursorsof Tyramine was detectedin small quantity in all tested chesses samples.
7. the amino acid Phenylalanine andArginine The precursors of both β-Phenylethylamine and putrescine was detected in all cheeses types in average ratio
8. Tryptophanand lysine theprecursorsofTryptamineand cadaverine was detected in all cheeses type excepted in Domiati cheeses in the case of Tryptophan and in Gouda cheeses in the case of Lysine.
9. The frequency of biogenic amines in Domiati cheesewere 100%of histamine and 100% of β-phenylethylamine,tyramine and putrescine were not detected
10. The frequency of biogenic amines in Ras cheese were 50% histamine 16% tyramine 50%putrescine and 33% β-phenylethylamine .
11. The frequency of biogenic amines in Cheddar cheeses were 83% histamine and 50% putrescine and 100% β-phenylethylamineand tyramine not detected
12. The frequency of biogenic amines in Gouda cheeses were 16% histamine, 16% tyramine, 83% putrescine and 100% β-phenylethylamine.
13. The frequency of biogenic amines in Blue cheese were 66%histamine,16%tyramine, 83%putrescine and 83%Β-phenylethylamine .
14. The high mean percent of Putrescine was inRas cheeses (4.3432) and the lowest was in Gouda cheeses (0.474) while putrescine was not found in Domiati cheeses.
15. The high mean percent ratio of Histamine was in Ras cheese (7.9165) while the lowest was in Domiati cheese (0.5643),on theother hand Histamine was found in one sample of Gouda cheese.
16. The high mean percent ofβ-phenylethylamine was in Ras cheese (0.9954) while the lowest was in Domiaticheeses (0.0874), on the other hand Tyramine was found in one sample of Gouda,Ras and Blue cheese
17. Cheeses can be arranged according to the levelof biogenic amines to:
1- Histamine: Ras<Blue cheese<Cheddar <Domiati <Gouda
2- Putrescine: Ras <Blue cheese<Cheddar < Gouda
3- β-phenylethylamine: Ras<Bluecheese<Cheddar<Gouda< Domiati