Food Tests Part 2 (SC) PDF

Starter- Questions 1. Name the 7 components of a balanced diet 2. Why are proteins required in the diet? 3. Name a source of carbohydrates 4. Why is fibre needed in the diet? 5. Name a vitamin and a food source. 6. Why are fats required in the diet? 7. Name a mineral and why it is requ...

Starter- Questions 1. Name the 7 components of a balanced diet 2. Why are proteins required in the diet? 3. Name a source of carbohydrates 4. Why is fibre needed in the diet? 5. Name a vitamin and a food source. 6. Why are fats required in the diet? 7. Name a mineral and why it is required in the diet C system L3- Food Tests Part 2 (Fats and glucose) Learning Objectives Name the tests for glucose and fats Describe how to undertake the tests for glucose and fats. Explain how you could use these test to determine the relative amounts of the food groups in each substance Syllabus Statements The 7 food groups Our bodies require 7 different food groups to stay healthy. We must make sure our diet contains the correct amount of each of the following: - Carbohydrates - Proteins - Fats - Vitamins - Minerals - Fibre - Water  CARBOHYDRATES? GLUCOSE OR STARCH FAT/ LIPID? X PROTEIN? Food Tests Today we will be looking at 2 food tests: - Fats (emulsion test) - Reducing sugars Testing: Fats/lipids If NO fat present, the ethanol stays colourless Ethanol is COLOURLESS to start If fats are present, the ethanol solution turns CLOUDY WHITE Testing for Fats/lipids You will need: - 2 large test tube - A pipette - Pestle and mortar - Ethanol 1. Crush some food in a pestle and mortar and place in a boiling tube. 2. Add some ethanol (about 1-2cm in depth). Mix 3. Add some water (about 1-2cm in depth) to a SEPARATE BOILING TUBE. 4. Carefully pour some of the ethanol from boiling tube number 1 into the water. (If it turns milky/cloudy white, there is fat present) 3. Lipids Food Type Colour change in Ethanol Positive (+)/ Negative (-) Cracker Crisp Bread Potato Apple Cheese Milk Egg White Testing for Reducing Sugars  Testing for Reducing Sugars You will need: - 5 test tubes - A pipette - Benedict’s solution - 2 large beaker of HOT water (that can hold 2/3 test tubes each) 1. Crush some food in a pestle and mortar and place in a boiling tube with a little water. OR if it is a liquid, just place 2cm3 liquid in the test tube. 2. Add 2cm3 Benedict’s solution (you need to have an equal volume of liquid and Benedict’s solution) 3. The test tubes must be HEATED. Place the test tube in the HOT water bath (must be above 80oC) 4. Repeat with the other foods/solutions. If it stays blue, there are no reducing sugars present. If it turns BRICK RED, there are lots of reducing sugars present. 4. Reducing sugars (glucose) Food Type Colour change in Benedict's Positive (+)/ Negative (-) Cracker Crisp Bread Potato Apple Cheese Milk Egg White : Fill in the blanks We can test foods to see which molecules they contain. To test foods for proteins, you use ____(1)____ solution. It is a __(2)____ colour that will turn _____(3)___ if proteins are present. To test foods for ____(4)___, you use _____(5)____ solution. It is a colourless solution that will turn _____(6)____ with a positive result. There are two types of carbohydrates we can test for. The first is ___(7)____ using iodine solution. It is ____(8)______ to start with and will turn ____(9)_____ with a positive test. The second type of carbohydrates are the reducing sugars. An example of a reducing sugar is _____(10)____. We test for reducing sugars using _________(11)___________. This is ____(12)____ to start with. If there is a small amount of sugar present, the solution will turn ______(13)_______. If there is a large amount of sugar present, the solution will turn _______(14)________. With this solution, you need to make sure you heat it in a ______(15)_________.