lute the solute, sodium chloride, outside the cell, the concentration of solute inside the cell would be greater than outside the cell so wa- ter will migrate from outside the cell into the cell , tissue will swell up!, since tissues in skull is rigid, the cells would be crushed and die and cause this problem. Video 9: - America’s favorite food: hot dogs, eat lots hot dogs, US : 20 billion hot dogs in US per year, 65 hot dogs per person and per year , - cured meat, ham and smoked meat, concerned is: the use of nitrite as preservative!, Sodium Nitrite, nitrite is added to cured meat is for taste, tangy taste, people like it!, has been used for immemorial time!, - how nitrite can affect the color of cured meat!, fresh meaty is bluish red , caused by Myoglobin(Fe+2), related to hemoglobin, chemical in our blood that carries oxygen, iron present in the form of iron plus 2, Mb react with oxygen and form oxymyoghobin , bright right color, fresh cut meat is wrapped in plastic wrap, that allows the air O2 to go give nice color , - after a while, iron will be oxidized to iron plus 3(from Fe+2 TO Fe+3), myoglobin will turn to brown color . Chemical called De- oxymyoglobin, in the absence of oxygen it is brownish color, people don’t like buy brown meat!!so thats the reason nitrite added to meat! - The presence of nitrite, myoglobin would be converted to nitro- somyoglobin(MbNO) , gives a pink color, with ham or hot dogs - nitrates and nitrites, similar because one gets converted into the other, Nitrates convert into nitrites, nitrites gets converted in the body by reacting with naturally occurring amines into nitrosamines(animal carcinogens), people concerned by taking ni- trites and nitrates , we would be subjected to this cancer causing chemicals. - not reason to worry ! most of nitrates we take in comes from Natural sources, (>90%), food and vegetables are naturally rich in nitrates which can be converted to nitrates, then nitrosamines , - VC, hot dogs would provide VC with nitrite, VC prevents the nitrite into chemical nitrosamine, - possible to have hot dogs /sausages without nitrites, but always risk with food poisoning, color not same, and keep refrigerated so toxin will not develop
- bacon ham and uncured, not been preserved, so keep cold, no ni- trites or nitrates added, so is in celery juice! but celery juice is rich in nitrates, and means nitrates present already! so same thing! not no preservative added are good! Video 10. - carbohydrates in our meal, - mashed potato , “ made from real potato”, ingredients : Anti-Oxi- dants , - oxygen will react with food and cause problems: fruit and vegeta- bles will cause browning, oxidation of fats(rancidity), anti oxidants prevent those - Prevent browning: apple cut open, turned brown, other one is clear, the metal in the knife helps promotes the oxidation of chemicals present naturally in apple, and turned brown, - you want trap the metal to prevent it from interaction with food - Citric acid , we can use, acts like bridge, traps the metal ion nor- mally will react with certain enzymes in food and cause food turn
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- Spring '11
- Food coloring, E number, Food additive