Abstract
The purpose of the study is to identify the highest concentration of starch and reducing sugars in a sample of five chosen fruits, namely watermelon, red grapes, green grapes, pineapple and orange. This study is important, since it indicates which of the above fruits would give the most energy as carbohydrates. Our hypothesis is that red grapes might have the highest glucose and starch concentration. We base this on the taste of all five samples, out of which red grape samples were the sweetest. The samples were then analyzed using two assays, Benedicts test as well as Acidic Iodine. Three technical replicates were done for pineapple and watermelon, and three biological replicates were done for grapes and oranges. Three standard curves were created for each assay. Equations obtained from the standard curves were used along with the absorbance to determine the concentrations of sugar and starch. The study used a spectrophotometer to record the absorbance of the fruit samples. While green grapes showed fructose and sucrose concentrations with traces of glucose, red grapes showed high glucose and some fructose concentrations. The other three fruits had large standard deviations and standard error, causing differences in the readings of both starch as well as sugars in all three replicates. While, pineapple had the highest starch concentrations, watermelons and grapes had the lowest starch concentrations. Similarly, red grapes had the highest glucose concentration, with green grapes having the lowest glucose concentration. The test results concluded, that the results did not support our hypothesis in case of red grapes having the highest starch concentration, but it supported our hypothesis in case of red grapes having the highest sugar concentration.
