Chemistry project on glucose content in fruit juices

CHEMISTRY PROJECT ON GLUCOSE CONTENT IN FRUIT JUICES NAME: Mudit Chhabra CLASS: XII-B ROLL NUMBER: SCHOOL: Goodley Public School YEAR: 2012-2013 SUBM SUBMIT ITTE TED D TO: TO: Shashwati Sen Gupta

Mrs

AIM TO DETERMINE THE AMOUNT OF GLUCOSE IN FRUIT JUICES.

ACKNOWLEDGEMENT I sincerely express my gratitude towards my chemistry

teacher Mrs Shashwati Sen Gupta for her expert guidance and suggestions given to me during this project. I gratefully acknowledge that without her valuable guidance and comments it would not have been possible for me to complete this project in time.

Name: Mudit Chhabra Class: XII – B

INTRODUCTION Carbohydrates are one of the most important bio molecules present in

living cells. These are widely distributed both in plants and animals. Carbohydrates are synthesized by plants by the process known as photosynthesis, given by the reaction. Glucose so formed is stored as starch , sucrose ,maltose, etc. in various parts of the plants e.g. glucose synthesized by leaves is stored as starch in potato, as sucrose in liquid form in sugarcane and beet root ,as juices in rice , as  juices in rice grains etc. Carbohydrates are regarded as hydrates of carbon and have general formula (CH20) n. Depending on hydrolysis, carbohydrates are of three types: • MONOSACCHARIDES:

Carbohydrates which cannot be

further hydrolysed to a simpler unit. Eg.glucose and fructose.

•

DISACCHARIDES:

Carbohydrates which yield two MONOSACCHARIDES units on hydrolysis. E.g. sucrose, lactose and maltose.

•

POLYSACCHARIDES:

Carbohydrates which yield large number of MONOSACCHARIDES units on hydrolysis, E.g. starch, glycogen and cellulose.

Glucose

It is an aldohexose and is most widely distributed monosaccharide. It occurs in large quantity in ripen grapes so it is called grape sugar. It also occurs in most other fruits like honey saps of plants in animal glucose is a source of energy and remains in blood and tissues by the reaction. An adult on an average contains 5 to 6 grams of glucose in blood which is sufficient to supply energy for 15 minutes. Excess of  glucose is stored in liver and glycogen and reconverted into glucose when required Hormone insulin controls glucose level in blood. A higher glucose level cause a disease called diabetes mellitus and is exerted in urine. Molecular formula of  glucose is:

THEORY  Glucose reacts with Fehling solution to form red precipitate of cuprous oxide. A known value of Fehling solution is titrated against a standard solution of  glucose and then with unknown / sample of grapes sugar juice, using methylene blue as indicator.

Fehling solution of two types: A=aq. Copper sulphate cuso4 (aq.) B=alkaline sodium potassium tartrate

Reaction of glucose and Fehling solutions is an oxidation reaction. A Fehling solution oxidizes aldehyde to carboxylic acid and gets reduced to cu +.

EXPERIMENT 1  APPARATUS REQUIRED

•

BURETTE

•

PIPETTE

•

CONICAL FLASK 

•

BURETTE STAND

CHEMICALS REQUIRED •

FEHLING SOLUTION OF A AND B

•

GLUCOSE (SOLID)

•

•

ORANGE JUICE , APPLE JUICE , PEAR JUICE AND POMEGRANATE  JUICE METHYLENE BLUE

EXPERIMENT FOR FRUIT   JUICES

PROCEDURE 1. Prepare Fehling solution by mixing equal volumes of Fehling solution A and B. 2. Take fruit juice and dissolve in 250 ml of distilled water, filled up to the mark. 3. Take the burette, clean it with chromic acid, then with distilled water. 4. Fill the burette up to convention point. React the lower meniscus of  the fruit juice in burette. 5. Pipette out 20 ml of Fehling solution in conical flask and boil the contents over the gauze. 6. Add fruit juice in hot Fehling solution from burette until the colour of the solution is Pale blue and then drop wise, till the colour  just disappears.

Observation table for standard glucose solution

S.NO

VOLUME INITIAL FINAL OF READING READING FEHLING (ml) (ml) SOLUTION (ml)

CONCORDANT VALUE =

CALCULATIONS (Standard glucose solution)

VOLUME OF THE GLUCOSE SOLUTION (ml)

ml

Fehling solution = Glucose solution

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose) M1*V1 = M1*20 = M1 = Strength of Glucose = Molarity * Molecular Mass

= =

Observation table for Orange Juice

S.NO

VOLUME INITIAL FINAL OF READING READING FEHLING (ml) (ml) SOLUTION (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE =

ml

CALCULATIONS (Orange juice)

Fehling solution = Glucose solution (Fruit juice) M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose) M (orange juice) = M (Fehling)*V (Fehling)/ V (Glucose)

= M (orange juice) = Strength of Glucose (orange juice) = Molarity * Molecular Mass

= = Percentage of glucose in orange juice = Strength of Glucose (orange juice)/ Strength of  standard Glucose

= = Orange juice consists of glucose =

Observation table for Apple Juice

S.NO

VOLUME INITIAL FINAL OF READING READING FEHLING (ml) (ml) SOLUTION (ml)

VOLUME OF THE GLUCOSE SOLUTION (ml)

CONCORDANT VALUE =

CALCULATIONS (Apple juice)

Fehling solution = Glucose solution (Fruit juice) M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose)

ml

M (Apple juice) = M (Fehling)*V (Fehling)/ V (Glucose)

= M (Apple juice) = Strength of Glucose (Apple juice) = Molarity * Molecular Mass

= = Percentage of glucose in Apple juice = Strength of Glucose (Apple juice)/ Strength of standard Glucose

= = Apple juice consists of glucose =

Observation table for Pear Juice

S.NO

VOLUME INITIAL FINAL OF READING READING FEHLING (ml) (ml) SOLUTION (ml)

CONCORDANT VALUE =

CALCULATIONS (Pear juice)

Fehling solution = Glucose solution (Fruit juice)

VOLUME OF THE GLUCOSE SOLUTION (ml)

ml

M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose) M (Pear juice) = M (Fehling)*V (Fehling)/ V (Glucose)

= M (Pear juice) = Strength of Glucose (Pear juice) = Molarity * Molecular Mass

= = Percentage of glucose in Pear juice = Strength of Glucose (Pear juice)/ Strength of standard Glucose

= = Pear juice consists of glucose =

Observation table for Pomegranate Juice

S.NO

VOLUME INITIAL FINAL OF READING READING FEHLING (ml) (ml) SOLUTION (ml)

CONCORDANT VALUE =

CALCULATIONS (Pomegranate juice)

VOLUME OF THE GLUCOSE SOLUTION (ml)

ml

Fehling solution = Glucose solution (Fruit juice) M (Fehling)*V (Fehling) = V (Glucose)*V (Glucose) M (Pomegranate juice) = M (Fehling)*V (Fehling)/ V (Glucose)

= M (Pomegranate juice) = Strength of Glucose (Pomegranate juice) = Molarity * Molecular Mass

= Percentage of glucose in Pomegranate juice = Strength of Glucose (Pomegranate juice)/ Strength of  standard Glucose

= = Pomegranate juice consists of glucose =

RESULT

Percentage of glucose in ORANGE juice = Percentage of glucose in APPLE juice = Percentage of glucose in PEAR juice = Percentage of glucose in POMEGRANATE  juice =