Testing for Vitamin C, sugars and the pH of local strawberries

Today we got some local strawberries to the laboratory so that we ould extract some juice from them. We used the electric mixer to do so. The strawberries' pulp was removed by passing the extracted liquid through a cheese cloth. We decided to do three tests : Vitamin C test, sugars test and pH test to determine whether the extracted liquid from strawberries is acidic or alkaline.

We split up so that the work can be equally shared among us. One of the students performed a titration on the strawberry liquid to test it for Vitamin C. The other student boiled some water in a beaker and put some strawberries extract in one test tube to test for the sugars present. Some Benedict solution was added to the test tube, the colour of the extract seemed to change. The last student needed to to test for pH by dipping the pH meter which is connected to the data logger, into the strawberry extract to find out its pH.

Unfortunately we noticed that the juice of the strawberries was too dark in colour to produce clear cut pH tests and titrations. This caused problems in the accuracy and reliability of the experiment.

Hence because of this reason and because of the problem of availability of strawberries, we decided to drop strawberries from our fruits list. We decided to replace these with lemons which are more abundant and whose juice is lighter.