Food Tests Review Food Tests OUP To be
Food Tests Review Food Tests © OUP: To be used solely in purchaser’s school or college
Food Tests Food © OUP: To be used solely in purchaser’s school or college
8 A Food – who needs it? What do we need food for? Energy to do things Raw materials to grow larger Raw materials to repair damaged body parts © OUP: To be used solely in purchaser’s school or college
8 A So what’s in food? Food is a complicated mixture of different chemicals. We can sort these chemicals into different types. What are the main types? Proteins Vitamins Fats Minerals Water Roughage Carbohydrates (starch and sugars) Can you make up a sentence with words starting with the same letters – a mnemonic? © OUP: To be used solely in purchaser’s school or college
8 A Which food contains which chemical? Which foods belong to which food groups? Proteins Water Proteins Fats © OUP: To be used solely in purchaser’s school or college Fats Carbohydrates Water
8 A What’s in food? We can test foods to find out what chemicals they contain. Orangey-brown iodine turns blue-black when it reacts with starch. drop iodine solution onto the food black = starch © OUP: To be used solely in purchaser’s school or college
8 A What’s in food? Blue Benedict’s solution turns orangey-red when it is boiled with glucose. chopped up food hot water heat © OUP: To be used solely in purchaser’s school or college blue turns orange/red = glucose
8 A What’s in food? In the Biuret test the solution turns purple. potassium hydroxide shake copper sulphate purple = protein chopped up food © OUP: To be used solely in purchaser’s school or college
8 A What’s in food? Fats go cloudy white when they are mixed with ethanol and water. filter grind food with ethanol add water cloudy = fat Now see if you can use these tests to identify the food chemicals on the next slides. © OUP: To be used solely in purchaser’s school or college
8 A What’s in food? For each food, decide on the chemicals found in them. Food sample Protein Test Result Iodine solution orangey-brown Benedict’s test blue Biuret test purple Ethanol test cloudy white Fats © OUP: To be used solely in purchaser’s school or college Starch Glucose
8 A What’s in food? For each food, decide on the chemicals found in them. Food sample Protein Test Result Iodine solution blue-black Benedict’s test blue Biuret test blue Ethanol test clear Fats © OUP: To be used solely in purchaser’s school or college Starch Glucose
8 A What’s in food? For each food, decide on the chemicals found in them. Food sample Protein Test Result Iodine solution orangey-brown Benedict’s test orangey-red Biuret test blue Ethanol test clear Fats © OUP: To be used solely in purchaser’s school or college Starch Glucose
8 A What’s in food? For each food, decide on the chemicals found in them. Food sample Protein Test Result Iodine solution orangey-brown Benedict’s test orangey-red Biuret test blue Ethanol test clear Fats © OUP: To be used solely in purchaser’s school or college Starch Glucose
8 A Vitamins Vitamin Found in Gives you A Liver, butter, green vegetables B 2 Healthy skin Cheese, milk, liver, eggs, green vegetables Citrus fruits, green Healthy teeth and vegetables, potatoes gums, without it you get scurvy C D Fish liver oil, eggs, sunlight on the skin © OUP: To be used solely in purchaser’s school or college Healthy skin and teeth Healthy bones – without it you get rickets (soft bones)
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