Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of...
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Transcript of Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of...
![Page 1: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/1.jpg)
Food TestsGrade8
![Page 2: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/2.jpg)
Test for starch
• Collect the food sample (liquid) in a test tube.
• Add few drops of iodine solution.(yellowish brown)
• If the colour changes from yellowish brown to blue black then thissubstance contains STARCH
![Page 3: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/3.jpg)
Test for fat
• Collect the food sample (liquid) in a test tube.
• Add ethanol and shake well.
• Add water.
• If a cloudy mixture appears then the food sample contains FAT.
![Page 4: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/4.jpg)
Test for protein
• Collect the food sample (liquid) in a test tube.
• Add 5 drops of copper sulphate.
• Add 5 drops of sodium hydroxide.
• If the colour changes from blue to purple then the food sample contains PROTIEN.
![Page 5: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/5.jpg)
Test for sugar (glucose)
• Collect the food sample (liquid) in a test tube.
• Add few drops of Benedict’s solution.
• Place the test tube in a boiling water bath.
• If the colour changes from blue to green to orange to a red deposit, then the sample contains SUGAR (GLUCOSE)
• The colour change depends on the concentration of sugar in the sample.
![Page 6: Food Tests Grade8. Test for starch Collect the food sample (liquid) in a test tube. Add few drops of iodine solution.(yellowish brown) If the colour changes.](https://reader035.fdocuments.net/reader035/viewer/2022062516/56649dd95503460f94acf19e/html5/thumbnails/6.jpg)
Turns cloudy white
Emulsion testFats
Turns purpleBiuret testProteins
Turns redBenedicts solution
Sugars
Turns blue-blackIodineStarch
ResultTestSubstance tested
Food tests
These are some of the most common food tests: