Study the variation in the amount of oxalate ions in guava fruit at different stages of ripening.
The objective of this project is to investigate the variation in the amount of oxalate ions present in guava at different stages of its ripening (i.e. unripe, parialy ripe and fully ripe).
Collect different samples of guava fruit (green, pale-green, yellowish-white and yellowish, i.e. from unripe to fully ripe variety). Take100 grams of one of the sample of guava fruit, crush it into a mortar and transfer the paste in 100 mL of water. Boil the contents for 10-15 minutes and filter. Take the filtrate, add about 5mL of dilute sulphuric acid and titrate it against 0.001M KMnO4 solution. Repeat the procedure with other samples of guava and draw conclusion.
A study to compare the quantity of caesin present in different samples of milk.
To compare the quality of different samples of milk by finding out quantity of casein present in them.
Take 200 mL of each sample of milk in separate 500 mL beakers. Heat the milk samples upto 50 – 60°C. Add a few drops of dilute hydrochloric acid slowly with constant stirring for 5-10 minutes. Casein coagulates as an amorphous substance. Filter the substance and wash the precipitate several times with tap water. Remove the fat by using a suitable organic solvent. Weigh casein so obtained after drying.
LABORATORY MANUAL CHEMISTRY
Preparation of soyabean milk and its comparison with natural milk.
To prepare soyabean milk and compare it with natural milk with respect to curd formation, effect of temperature, taste etc.
Prepare soyabean milk by first soaking soyabean seeds in warm water and keeping them overnight in water. Make a paste of seeds by crushing and finely grinding them. Mix the pasty mass with warm water to get soya milk. Filter the mixture and discard the undissolved portion. Compare soya milk with natural milk and conclude whether soya milk can be a substitute for natural milk. The comparison may be made with respect to the nutrients present, colour, smell, taste, effect of temperature, curd formation, etc.
Study the effect of potassium metabisulphite as a food preservative under various conditions.
To study the effect of concentration of potassium metabisulphite (preservative), temperature and time on preservation of food.
Collect amla fruits and wash these with water. Cut these into small pieces and dry in the sunlight for a few hours. Mix the salt and the spices to the pieces. Pour 25g of amla pieces into each of the six boiling tubes numbered as 1, 2, 3…etc. Weigh 500 mg of potassium metabisulphite and dissolve it in 20 mL of distilled water. Keep the boiling tube No. 1 without mixing preservative and oil. In boiling tube No. 2 and 3 add 1 mL of the preservative solution and 2 mL of oil and mix the mixture with the glass rod. Keep the boiling tube No. 2 at the room temperature (25-350C) and the boiling tube No. 3 at a temperature of 400C. In boiling
tube No. 4,5and 6, add 2 mL, 4 mL and 8 mL of the preservative solution respectively and 2 mL of mustard oil. Keep these boiling tubes at the room temperature. Prepare again the fresh mixtures in boiling tubes No. 4, 5 and 6 and keep them at 40°C temperature. Keep all these boiling tubes for 3 to 5 days. Note the growth of fungi, if any, in these tubes. Record your observations and draw conclusion.
A Study of enzymatic hydrolysis of starch
Study the hydrolysis of starch by salivary amylase and the effect of pH and temperature on it.
Take about 20-30 mL of warm distilled water (30°C– 40°C) in the mouth and mix it with the saliva by gargling in the mouth. Collect the saliva mixed water in a beaker.
Digestion of Starch by Saliva...