Question

Wheat, rice, chickpea and Green Banana flour were tested for % Starch content via first adding α-amylase solution to cut starch molecules into smaller pieces and then adding amyloglucosidase to cut convert those smaller pieces into individual molecules of glucose.

GOPOD Reagent was added to each solution of Wheat, rice, chickpea and green banana flour. GOPODputs a coloured tag on carbon 1 of each glucose molecule. The number of coloured tags is measured by absorbance at 510 nm enabling quantification of the amount of glucose, and therefore starch.

Green Banana, chickpea, rice and wheat were

58.99, 23.29, 64.11 and 60.73 Respectively

1) Why would you expect total starch to be less than 100%? (In terms of genetic make up and structure of each starch source)

2) What explains the differences between each sample of starch within each sample? (In particular why does Green Banana vary in % Starch and Chick pea have low starch %)

Answer 1

1. The total starch is expected to be less than 100% because not all glucose is used for the formation of starch. Glucose is present in many other forms as well in a plant. Celluose is a common polymer of glucose and is present in the cell walls. Glucose may also be present along with other sugars to form oligosaccharides which serve as important sources of energy.

2. Quantification of glucose by measuring the absorbance at 510 nm shows the amount of glucose in each sample.The quantity of glucose is co-related with the quantity of strach in each sample. Among the four samples, rice and wheat have the highest propotions of glucose, which is followed by green banana and and then chickpea possesing the lowest amount of glucose. Rice contains the maximum amount of starch. On the other hand chickpeas possess low starch content and high protein content.