Chemistry Investigatory Project Analysis Essay Example

of yeast cells according to Pasteur's theory. However, it is now understood that fermentation occurs due to the presence of 'non-living' complex nitrogenous substances known as enzymes within the yeast cells.

The major constituent of Diastase Wheat flour, gram flour, and potato juice is starch. Starch in the food material is first dissolved in a solution. In the presence of the enzyme diastase, starch undergoes fermentation to produce maltose. Starch is converted to maltose according to the equation 2(C6H10O5) n + nH2O > nC12H22O11. Starch reacts with iodine to give a blue-violet color, but the product of fermentation starch does not show any characteristic color. Completion of fermentation is indicated by the reaction mixture no longer giving a blue-violet color with iodine solution. By comparing the time it takes for different substances with equal amounts of starch to complete fermentation, it is possible to compare the rates of fermentation. The diastase enzyme is obtained by germinating moist barley seeds in darkness at fifteen degrees Celsius. Once germination is complete, the temperature is raised to sixty degrees Celsius to stop further growth. These seeds are crushed in water and filtered to obtain a solution containing the diastase enzyme, which is known as malt extract.

The materials needed include conical flasks, test tubes, funnel, filter paper, water bath, wheat flour, gram flour, rice flour, potatoes, and 1% iodine solution.

Procedure: 1. In a 100 ml conical flask, take 5.0 g of wheat flour and add 30 ml of distilled water. 2. Boil the contents of the flask for approximately 5 minutes. 3. After cooling, filter the mixture to obtain wheat flour extract. 4. Add 5 ml

of 1% aq. NaCl solution to the wheat flour extract in a conical flask. 5. Place the flask in a water bath at a temperature of 50-60 degrees Celsius and add 2 ml of malt extract. 6. Take 2 drops of the reaction mixture after 2 minutes and mix with diluted iodine solution to observe the color produced. 7. Repeat this step every 2 minutes until no bluish color is observed, indicating completion of fermentation. Record the total time taken for fermentation to complete. 8. Repeat the experiment using extracts from gram flour, rice flour, and potato, and note the observations.