Q#5 - How do you know when a test is positive

for glucose and starch?

You will know a test is positive for glucose and starch when Benedict's reagent will give a positive test result for glucose but not for starch.

Explanation:

Benedict's Test is used to test for simple carbohydrates. The Benedict's test identifies reducing sugars which have free ketone or aldehyde functional groups. Food scientists can test for starch in food using iodine solution. If starch is present, the iodine will turn dark blue. Testing for sugar can be performed with Benedict's solution. The Benedict's solution is added to the sample, and heated for five minutes. The test involves heating a solution of the sugar to be tested with Benedict's reagent and observing the colour change of blue to orange. Benedict's reagent will give a positive test result for glucose but not for starch. Benedict's solution can be used to test for the presence of glucose in urine