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S. No.

Title Page No.

1 Acknowledgement 2

2 Certificate 3

3 Introduction 4-6

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Experiment-Aim

-Theory-Materials required

-Procedure-Result

7-11

5. Conclusion 12

6. Bibliography 13

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It is my utmost pleasure to express deep sense of gratitude towards

____________, my Chemistry teacher, who directed me to complete this

project successfully. I am also thankful to ________for accompanying me in this work as fellow team members’ and____________, the Chemistry lab assistant. Their valuable guidance,

support and supervision are considerably responsible for helping this project attain its present form.

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This is to hereby certify that the original and genuine investigatory

project has been completed sincerely and satisfactorily by Sandeep Sinha of

class XII – C, Loyola High School regarding her project titled “Analysis of Vegetable and Fruit Juices” as

per the CBSE practical work requirement for the session 2012-

2013.

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Teacher’s Signature Examiner’s Signature

Our body needs important nutrients to support its healthy condition that is why it is imperative that our food consumption should include healthy foods that contain good amount of nutrients sufficient enough to supply our body with its required daily nutrition. Nutrients like carbohydrates, proteins, fats, vitamins, minerals, etc. are play vital and specific role to develop and sustain body.

This project deals with finding out various constituents and compositions of vegetables and fruits. Analyzing the type of nutrient present in a food item helps plan a balanced diet. A balanced diet can be prepared according to the energy requirement which varies depending on age, sex, size, metabolic rate and activity level.

In this project presence of Carbohydrates, proteins, fats and minerals is analyzed through different experiments. Following is a brief note on these nutrients.

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CARBOHYDRATES The carbohydrates are the optically active polyhydroxy aldehydes or ketones or the compounds which produce such units on hydrolysis. Carbohydrates are the most common source of energy in living organisms. Foods high in simple carbohydrates include fruits, sweets and soft drinks. Foods high in complex carbohydrates include breads, pastas, beans, potatoes, bran, rice, and cereals. Carbohydrates are used as storage molecules as starch in plants and glycogens in animals.Carbohydrates may be classified chemically as monosaccharide, disaccharides, or polysaccharides depending on the number of monomer (saccharide or sugar) units they contain. Carbohydrate contains 15.8 kilo joules  (3.75 kilocalories) per gram. Role of carbohydrates in body is as follows: -Providing energy and regulation of blood glucose-Biological recognition processes-Dietary fiber-Sparing the use of proteins for energy-Breakdown of fatty acids and preventing ketosis.Not only these, furniture, etc. are built from cellulose; clothes are made of cellulose in form of cotton fiber. They provide raw material for industries like textiles, paper, lacquers and breweries.

Some chief sources of carbohydrates

PROTEINS

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Proteins (also known as polypeptides) are organic compounds made of amino acids arranged in a linear chain and folded into a globular form. Proteins are the basis of many animal body structures (e.g. muscles, skin, and hair). They also form the enzymes that control chemical reactions throughout the body. Each molecule is composed of amino acids, which are characterized by inclusion of nitrogen and sometimes sulphur (these components are responsible for the distinctive smell of burning protein, such as the keratin in hair). The body requires amino acids to produce new proteins (protein retention) and to replace damaged proteins .As there is no protein or amino acid storage provision, amino acids must be present in the diet.  Protein contains 16.8 kilojoules (4 kilocalories) per gram. In the case of protein, this is somewhat misleading as only some amino acids are usable for fuel. Chief sources of protein are milk, pulses, fish, meat, etc.

FATS

A molecule of dietary fat typically consists of several fatty acids (containing long chains of carbon and hydrogen atoms), bonded to a glycerol. They are typically found as triglycerides (three fatty acids attached to one glycerol backbone). Fats may be classified as saturated or unsaturated depending on the detailed structure of the fatty acids involved. Fats contain 37.8 kilojoules (9 kilocalories) per gram.

MINERALS

Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen that are present in nearly all organic molecules.

Calcium, a common electrolyte, but also needed structurally (for muscle and digestive system health, bone strength, some forms neutralize acidity) may help clear toxins, provides signaling ions for nerve and membrane functions.

Magnesium, required for processing ATP and related reactions (builds bone, causes strong peristalsis, increases flexibility, increases alkalinity)

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Phosphorus, required component of bones; essential for energy processing prevent anemia.

AIMTo detect the presence of carbohydrates, proteins, oils and fats and minerals in vegetable and fruit juices.

THEORYThe presence of carbohydrates, proteins and fats in any food is detected by performing tests with the extract of the food. The vegetables and fruits are tested for these nutrients with the help of tests such as Molisch’s Test, Fehling’s Test,

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   * Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu  ** Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

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Tollen’s test, Ninhydrin test, Millon’s test, etc. Test for minerals are also performed.

MATERIALS REQUIREDJuices of vegetables -tomato, potato, raddish and fruits -apple, orange, grape, test tubes, laboratory reagents like iodine soln., ninhydrin soln., Fehling’s soln. A and B, Benedict’s reagent, Tollen’s reagent, mineral acids like HNO3 and Bunsen burner.

PROCEDURE- TESTS, OBSERVATIONS AND

INFERENCE

The fruits and vegetables whose juices are to be tested are cut into small pieces. The juices are extracted by using a juicer. The juices are filtered with the help of a filter paper. The filtrate is taken out and subjected to various tests for carbohydrates proteins, fats and minerals. Then tests are carried out in following manner:

I. TEST FOR CARBOHYDRATES

TEST OBSERVATION INFERENCE

1. TOLLEN’S TESTTake 20 ml of given juice in a test tube and add 2ml of Tollen’s reagent (Ammonical silver nitrate). Heat the contents in a water bath.

A shinning silver mirror is obtained on the inner side of the test tube is obtained in the test for all the juices except orange.

The presence of CHO group of carbohydrate in tomato, potato, radish, apple, grapes is confirmed. While it is absent in orange.

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2. FEHLING’S TESTTake equal volume of Fehling solution A and B in a test tube. Add two drops of NaOH followed by 2ml of given juice. Heat the contents in a water bath.

Reddish brown precipitate is obtained in the test for all the juices except orange.

This confirms the presence of CHO group of carbohydrate in tomato, potato, radish, apple and grapes .While it is absent in orange.

3.MOLISCH’S TESTTake 2ml of given juice in a test tube and add a few drops of Molisch’s reagent (Alpha-nephthol) followed by conc. H2SO4 through the sides of the test tube.

A red, purple or violet ring is produced at the junction of the two layers in the test for all the juices except orange.

The presence of CHO group of carbohydrate in tomato, potato, radish, apple, grapes is again confirmed. While it is absent in orange.

II. TEST FOR PROTEINS

TEST OBSERVATION INFERENCE

1. BIURET TESTTake 2ml of given sample in a test tube and add NaOH soln. followed by 2-3 drops if CuSO4 soln. Shake the contents well.

Blue color changes to violet for all the juice samples.

This confirms the presence of proteins in tomato, potato, radish, apple, orange and grape.

2. NINHYDRIN TESTTake 2ml of given sample juice in a test tube and add 1ml of Ninhydrin

Blue color is observed in all the samples of juices.

The presence of proteins in tomato, potato, radish, apple, orange and grape is confirmed again.

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reagent in it and warm it.

III. TEST FOR FATS

TEST OBSERVATION INFERENCE

1. TRANSLUCENT TESTPress a little of substance in a filter paper and then unfold the filter paper.

A translucent, greasy spot is observed only in the case of potato and apple. However no translucent spot is observed for other samples.

This shows that oil or fat is present in potato and apple while absent in tomato, radish, orange and grape.

2. MISCIBILITY TESTTake 2ml of sample juice in a test tube. Add water and shake the contents well.

The liquid of potato and apple is immiscible while that of other is miscible with water.

This again shows that oil or fat is present in potato and apple while absent in tomato, radish, orange and grape.

3.ACROLIN TESTTake 2ml of sample juice and add a few crystals of KHSO4 and heat the mixture.

Pungent smell of acrolin is observed in the test for potato and apple.

This confirms the presence of oil or fat in potato and apple. Also absence of fats is confirmed in tomato, radish, orange and grape.

III. TEST FOR MINERALS

TEST OBSERVATION INFERENCE

1. Test for Calcium.2 ml of the sample is

Appearance of white ppt. is observed in all the

This confirms the presence of calcium in

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taken and NH4Cl and NH4OH are added. The above solution is filtered and to the filtrate 2ml of ammonium oxalate soln. is added.

sample juices. tomato, potato, radish, apple, orange and grapes.

2. Test for Magnesium2ml of the sample is taken and NH4OH soln. is added. Scratch the sides of the test tube with a glass rod.

Appearance of white ppt. is observed in test for orange, tomato and potato.

Presence of magnesium is confirmed in orange, tomato and potato. While it is absent in radish, apple and grapes.

3. Test for Iron2ml of the sample is taken and to it 1 drop of conc. HNO3 is added, heated and cooled. Add 2-3 drops of potassium sulphocyanide soln.

Appearance of a blood red color precipitate is obtained in the case of potato, apple and orange.

This confirms the presence of iron in potato, orange and apple and its absence in tomato, radish and grapes.

4. Test for PhosphorousTake 2ml of the juice and to it, add 1 drop of conc. HNO3.Boil the soln. and add ammonium molybedate.

Appearance of yellow ppt. is obtained in tomato, potato and grapes.

The presence of phosphorous is confirmed in tomato, potato and grapes. While it is absent in radish, orange and apple.

RESULTAfter performing the tests for carbohydrates, proteins, fats and minerals, following can be concluded about their presence in different vegetables and fruits.

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Tomato contains carbohydrates, proteins, calcium, magnesium and phosphorous.

Potato contains carbohydrates, proteins, fats, calcium, magnesium, iron and phosphorous.

Radish contains carbohydrates, proteins and calcium. Apple contains carbohydrates, proteins, fats, calcium and iron. Orange contains proteins, calcium, magnesium and iron. Grape contains carbohydrates, proteins, calcium and phosphorous.

After analyzing the vegetables and fruits it can be well concluded that all of them contain one or the other compounds vital for body functioning.

It is observed that carbohydrate is a predominant constituent while fats are not present in most of the tested items. It is a natural merit, as living organism require carbohydrate the most common for generating energy. Among minerals presence of calcium is considerable as its present in all

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the selected food items. Iron, magnesium and phosphorous are present sufficiently. Many other minerals form constituents of vegetables and fruits, but in trace quantities as body require them very less.

The results throw a light on significance of vegetables and fruits as their constituents are vital compounds and nutrients. The deficiency of these nutrients can lead to various metabolic disorders. So, besides cereals, milk and its products and non-vegetarian food items, vegetable and fruits must be included in a daily balanced diet of all. More effort is required to make everyone realizes their significance for a healthy, disease-free, long lifestyle.

Frank Senior Secondary Chemistry Practicals for Class XII

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NCERT Chemistry Textbook for Class XII- Part II