Testing for reducing sugars
Steps
Put a known volume of the extract you wish to test for reducing sugar
Place a beaker on a heat proof mat
Carefully half fill the beaker with boiling water from a kettle ( or place the beaker on a tripod and gauze and boil the water wiwth a bunsen burner)
Add the same volume of Benedict solution to the test tube containing the food extract and put it into the hot water
Benedict solution is bright blue
Precaution
Safety: eye protection
Results
Positive test
Benedict solutions turns orange or red ( it will turn green-yellow-orange-red)
Negative test
Benedict solutions remains bright blue
Extract does not contain any reducing sugars
Green- extract contains a little of reducing sugars
Deep orange - extract contains a lot of reducing sugars
If u leave the test tube to cool, you will se a precipitate
Follow the safety procedures (listed in Chapter 1) when lighting your Bunsen burner. Do not light it in a shelf or enclosed space. Remove all notebooks, papers and excess chemicals from the area. Tie back any long hair, dangling jewelry and loose clothing and never leave an open flame unattended while it is burning.
When handling the test tubes, especially when they are hot, use a test tube holder and wear goggles.
