Investigation to analyse some fruit and vegetable juices for the contents present in them.
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CERTIFICATE This is to certify that Ravi Aggarwal has worked on the project on the subject entitled "Analysis of Fruits and Vegetable juices" has faithfully carried out the study under my guidance and supervision and to my total satisfaction. The accompanying report that he has submitted is his genuine work and all the results are true to the best of my knowledge. MRS. PURNIMA SAIGAL (Project Supervisor) ACKNOWLEDGEMENT I express my sincere thanks to Mrs. Purnima Saigal and Mrs. Kavita Kapoor who acted as my guide and inspired me at every stage to understand and compile this project. I am also grateful to the lab assistant Mr. Ashok to provide me the apparatus required for the project. Ravi Aggarwal Roll No. - INTRODUCTION Fruits and vegetables are important components of our diet. We take fruits in raw state or in the form of juices, while vegetables are taken in the cooked form or sometimes as juices. Fruits and vegetables provide us carbohydrates, proteins and various other important organic compounds. The juices are rich sources of minerals, vitamins and many micronutrients (calcium, iron etc.) essential for us. For example, iron deficiency in humans causes anaemia and anaemic persons are advised to take leafy vegetables e.g. spinach and apples which fills up the iron deficiency. Vitamin-C deficiency causes scurvy which results in bleeding of gums. This disease can be cured by taking plenty of Vitamin-C rich fruits like lemon, orange, guava, amla, etc. Some fruits like papaya and vegetables like carrot are rich in vitamin A which is essential for eyes to prevent night blindness.
Important sources of fats & carbohydrates are peanuts, coconut, soyabean, butter, cottonseeds mustard, etc. Identification Tests A. Fats and oils have generally low melting points. If a fat is shaken with either ethanol or chloroform in a dry test tube, it dissolves giving a clear solution. B. To the given oil or fat sample , add few crystals of potassium hydrogen sulphate (KHSO4). After heating, a pungent irritating odour due to the formation of acrolein confirms the presence of an oil or a fat. The oil or fat on heating undergoes hydrolysis to give glycerol and fatty acids. The glycerol thus produced on strong heating undergoes dehydration to form acrolein which has irritating smell. Oil or fat Glycerol + Fatty Acids CH2OH CH2 CH2OH CH + 2H2O CH2OH CHO 3. PROTEINS Proteins are essential organic compounds for any living system to build and repair our body. Proteins are main constituents of muscles, blood, skin, hair and other body parts. Besides carbon, hydrogen and oxygen, other elements such as nitrogen and sulphur are in proteins. Proteins are made up of chains of amino acids and are very essential components of our food. Beans, pulses, fish, meat, milk, cheese, etc. are rich sources of proteins. Identification Tests A. Biuret Test In this test, proteins when heated with strong alkaline copper sulphate (blue) give a violet or pink colour. This test is meant for testing the compounds having having a CONH2 group called peptide linkage. As the proteins contain long chains of peptide linkages, they give positive biuret test by forming complex with Cu2+ ions.
If there is an effervescence due to the evolution of carbon dioxide, it shows the presence of a carboxyl group. RCOOH + NaHCO3 RCOONa +CO2 + H2O TEST FOR APPLE JUICE TEST FOR COCUNUT WATER TEST FOR TOMATO JUICE RESULTS CONTENTS APPLE JUICE COCUNUT WATER TOMATO JUICE CARBOHYDRATES YES YES YES PROTEINS YES NO NO FATS AND OILS YES YES NO UNSATURATION YES YES YES HYDROXYL GROUP YES YES YES ALDEHYDE GROUP YES YES YES CARBOXYLIC GROUP YES YES YES CONCLUSION : After analyzing the fruits and vegetable juices, the following opinion emerges about the compounds present in them. CARBOHYDRATES : The carbohydrates are the main constituents of all the fruits and vegetable juices but are present in varying quantities. FATS AND OILS : Fats are rarely found in fruits and vegetables. But in the present study, the two juices (apple and coconut) show the presence of fats but it is not found in case of tomato. PROTEINS : Most of the fruits and vegetables contain proteins. In the present study, the coconut water and tomato juice did not show the presence of proteins. UNSATURATION : Since each fruit and vegetable consists of carbohydrates, fats & proteins, the presence of double or triple bonds between carbon atoms is must. Therefore, almost all fruits and vegetables have unsaturated compounds. HYDROXYL GROUP : This group is present in all the fruits and vegetable juices. But as compared to fruit juices, this group is present more in vegetable juices. ALDEHYDE GROUP : Aldehydes are type of carbohydrates. They are present in almost all the juices in large or small quantities. CARBOXYLIC ACID GROUP : It is also present in all the vegetables and fruit juices.
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