NITTE INTERNATIONAL SCHOOL

BANGALORE

Session:-2019-2020

Chemistry investing project

Topic:-To study the presence and strength of oxalate

ions in guava in different stages of ripening.

SUBMITTED BY: SATHVIKA.

SUBMITTED TO: Ms. Aruna
CLASS: XIISCIENCE
ROLL NO:
 CERTIFICATE

Certificate This is to certify that this chemistry

Investigatory Project on the topic ‘’the
presence of oxalate ions in guava’’ has been
successfully completed by SATHVIKA of class XII
– A under the guidance of Mrs. Aruna in
particular fulfillment of the curriculum of
Central Board of Secondary Education {CBSE}
leading to the award of annual examination of
the year 2019-20.

In charge teacher Internal examiner

Principal’s signature External Examiner

 ACKNOWLEDGMENTS

I have taken efforts in this project. However, it

would not have been possible without the kind
support and help of many individuals. I would like to
thank my principal MRS. SANDHYA SINGH and
school for providing me with facilities required to
do my project. I am highly indebted to my chemistry
teacher, MrsAruna. for her invaluable guidance
which has sustained my efforts in all the stages of
this project work. I would also like to thank my
parents for their continuous support and
encouragement. My thanks and appreciations also
go to my fellow classmates and the laboratory
assistant in developing the project and to the
people who have willingly helped me out with their
abilities.
contents
 Aim of the project
 Abstract
 Introduction
 Requirements
 Procedure
 Observation
 Calculation
 Conclusion
 Bibliography
 Abstract
The main objective of the project is study the presence of oxalate ions
in guava in different stages of ripening

The experiment used for the testing is titrimetric analysis

Different types of guava were used to check the oxalate ions.the results
were noted down

From the experimental result its evident that ripened guava contains
maximum amount of oxalate on than semi-ripened and unripened
guavas
Introduction
Guava is a common sweet fruit in India and many other places around

the world . Guava are plants in the Myrtle family (Myrtaceae) genus

psidium meaning pomegranate in Latin which contains about 100

Species of tropical shrub. On ripening it turns yellow in color. Rich in

Vitamin C, this fruit is a rich source of oxalate ions whose content

Varies during the different stages of ripening.

Guavas have a pronounced and typical fragrance , similar to lemon rind

But less in strength.

What is Oxalate?
Oxalic acid is an organic compound found in many plants. These include
leafy greens, vegetables, fruits, cocoa, nuts and seeds In plants, it’s
usually bound to minerals, forming oxalate. The terms “oxalic acid” and
“oxalate” are used interchangeably in nutrition science.Your body can
produce oxalate on its own or obtain it from food. Vitamin C can also be
converted into oxalate when it's metabolized Once consumed, oxalate
can bind to minerals to form compounds, including calcium oxalate and
iron oxalate. This mostly occurs in the colon, but can also take place in
the kidneys and other parts of the urinary tract.For most people, these
compounds are then eliminated in the stool or urine. However, for
sensitive individuals, high-oxalate diets have been linked to an increased
risk of kidney stones and other health problems.
Oxalate is an organic acid found in plants, but can also be synthesized
by the body. It binds minerals, and has been linked to kidney stones and
other health problems.
Oxalate Can Reduce Mineral Absorption

One of the main health concerns about oxalate is that it can bind to

minerals in the gut and prevent the body from absorbing them.For

example, spinach is high in calcium and oxalate, which prevents a lot of

the calcium from being absorbed into the body Eating fiber and oxalate

together may further hinder nutrient absorption Nevertheless, it's

important to remember that only some of the minerals in our food will

bind to oxalate.Even though calcium absorption from spinach is

reduced, calcium absorption from milk is not affected when milk and

spinach are consumed together Oxalate can bind to minerals in the gut

and prevent some of them from being absorbed, particularly when

combined with fiber.

Oxalate May Contribute to Kidney Stones

Normally, calcium and small amounts of oxalate are present in

the urinary tract at the same time, but they remain dissolved and

cause no problems.However, sometimes they bind to form

crystals. In some people, these crystals can lead to the formation

of stones, especially when oxalate is high and urine volume is

iow.Small stones often don't cause any problems, but large

stones can cause severe pain, nausea and blood in the urine as

they move through the urinary tract.Although there are other

types of kidney stones, about 80% are made up of calcium

oxalate For this reason, people who have had one episode of

kidney stones may be advised to minimize their consumption of

foods high in oxalate However, across-the-board oxalate

restriction is no longer recommended to every person with

kidney stones. This is because most of the oxalate found in urine

is produced by the body, rather than absorbed from food Most

urologists now only prescribe a strict low-oxalate diet (less than

50 milligrams per day) for patients who have high levels of

oxalate in their urine.Therefore, it's important to be tested from

time to time to figure out how much restriction is necessary.

High-oxalate foods may increase the risk of kidney stones in

susceptible people, and recommendations for patients are based

on urinary levels.
Proposed mechanism of renal oxalate handling

HIGH EXPRESSION
Does it Cause Any Other Problems?

Some claim that a high oxalate intake may be linked to the

development of autism. Others say oxalates may be linked to

vulvodynia, which is characterized by chronic, unexplained

vaginal pain.Based on study results, researchers believe neither

of these disorders are likely triggered by dietary oxalates

However, when 59 women with vulvodynia were treated with a

low-oxalate diet and calcium supplements, nearly a quarter

experienced improvements in symptoms The authors of that

study concluded that dietary oxalate might worsen, rather than

cause, the condition.Several online anecdotes do link oxalates

with autism and vulvodynia, but only a few studies have looked

into possible connections. Further research is needed. Some

people have suggested that consuming foods high in oxalate

may lead to autism and vulvodynia, but at this point the research

does not support these claims.

Most Foods with Oxalates Are Very Healthy

Some proponents of low-oxalate diets say people are better off

not consuming foods rich in oxalates, since they may have

negative health effects.However, it's not that simple. Many of

these are healthy foods that contain important antioxidants, fiber

and other nutrients. Therefore, it's not a good idea for most

people to completely stop eating high-oxalate foods. Many

foods that contain oxalates are delicious and provide many

health benefits. Avoiding them is not necessary for most people,

and may even be detrimental.

Your Gut Determines Oxalate Absorption

Some of the oxalate you eat can be broken down by bacteria in

the gut, which happens before it can bind to minerals. One of

them, Oxalobacter formigenes, actually uses it as an energy

source. It significantly reduces the amount your body absorbs

However, some people don't have much of this bacteria in their

gut, as antibiotics decrease the number of O.

formigenes colonies more, studies have found that people with

inflammatory bowel disease have an increased risk of

developing kidney stones .This is partly because they are unable

to regulate the amount of oxalate they absorb.

Similarly, elevated levels of oxalate have been found in the

urine of patients who have had gastric bypass surgery or other

surgeries that alter gut function .

This suggests that people who have taken antibiotics or suffer

from gut dysfunction may benefit more from a low-oxalate diet.

Most healthy people can consume oxalate-rich foods without

problems, but those with altered gut function may need to limit

their intake.
Natural and synthetic metal oxalate
Foods High in Oxalate

Oxalates are found in almost all plants, but some plants contain

very high amounts while others have very little. Animal foods

contain only trace amounts.Foods high in oxalate (100–900 mg

per serving) include:

 Beet greens

 Rhubarb

 Spinach

 Beets

 Swiss chard

 Endive

 Cocoa powder
List provides the oxalate content of many foods. The amount of

oxalates in plants varies from extremely high to very low, and

"high-oxalate" is classified as 100–900 mg per serving.

One formula unit in the crytal

How to Do a Low-Oxalate Diet

People who are placed on low-oxalate diets for kidney stones are

usually instructed to eat less than 50 mg of it each day. Here are

a few tips on how to follow a low-oxalate diet:

1. Limit oxalate to 50 mg per day: Choose a variety of

nutrient-dense animal and plant sources from this list

of foods very low in oxalate.

2. Boil oxalate-rich vegetables: Boiling vegetables can

reduce their oxalate content from 30% to almost 90%,

depending on the vegetable.Drink plenty of water: Aim for

a minimum of 2 liters daily. If you have kidney stones,

drink enough to produce at least 2.5 liters of urine a day .

 3. Get enough calcium: Calcium binds to oxalate in the gut

and reduces the amount your body absorbs, so try to get

about 800–1,200 mg per day.

4. Foods high in calcium and low in oxalate include:

 Cheese

 Plain yogurt

 Canned fish with bones

 Bok choy

 Broccoli

Diets with less than 50 mg of oxalate per day can be balanced

and nutritious. Calcium also helps reduce its absorption.

Requirements:-

Apparatus
1. 100 ml measuring flask
2. Pestle and Mortar
3. Beaker
4. Burette
5. Funnel
6. Filter paper
7. Weighing machine
8. Filter
Procedure:-
[1]Weigh 50g of fresh guava and crushed it to a fine pulp using
pestle and mortar.
[2] Transfer the crushed pulp to a beaker and add about 50ml
dilute H2S04 to it.
[3] boil the content for about 10minutes.cool and filter the
contents in a 100mlmeasuring flask.
[4]make up the volume to about 100ml by adding ample
amount of distilled water.
[5] take 20ml of the solution from the flask and add 20ml of
dilute sulphuric acid to it.
[6]heat the mixture and titriated it against [n/10]KMn04
solution taken in a burette till the end point have an
appearance of pink colour.
[7]repeat the above experiment with 50g of 1day,2day and
3day old guava fruits.
Observation:-
1.Weight of the guava fruit for each time was 50g.
2. volume of guava extract taken for each titration was 20 ml.
3.normality of KMn04 solution was[1/10].
4.END POINT :color changes to pink guava solution.

1]for raw guava:

s.no. Initial burette Final burette Concurrent
reading reading reading [ml]
1 0 9.6
2 0 9.5 9.6
3 0 9.6

2]for semi-ripening guava:

s.no. Initial burette Final burette Concurrent
reading reading reading [ml]
1 0 8.4
2 0 8.6 8.4
3 0 8.4
3]for ripe guava:
s.no. Initial burette Final burette Concurrent
reading reading reading [ml]
1 0 7.3
2 0 7.5 7.5
3 0 7.5
Calculations:-
1]for raw guava :
N1V1=N2V2
N1X10=[1/10]X9.6
1/10XNormality of oxate =[x/100]
=strength of oxalate
=normality x Eq.mass of oxalate in fresh guava extract
=9.6/100x44g/l-1 of diluted extract
=4.224g/l-1
2]for semi ripened guava [1dayold]
Strength of oxalate in one day old guava exract
=[8.4/100]x44g/l-1 of diluted extract
=3.696g/l-1
3]for ripening guava :
Strength of oxalate in fresh guava extract
=[7.5/100]x44g/l-1 of dilute extract
=3.3g/l-1
Results:-
The normality fresh of oxalate ions of:
i]fresh guava solution is 9.6ml
ii]semi-ripen guava solution is =8.4ml
iii]ripenined guava solution is =7.5ml
b]the strength of oxalate ions of:
i]fresh guava solution is =4.224g/l-1
ii]semi-ripened guava is =3.693g/l-1
iii]ripened guava is =3.3g/l-1
Conclusions:-

The content of oxalate ions in guava was found to be 59.61per

cent ,which is close to the literature valuve of 60 per cent .It
was also noticed that the content of oxalic ions grows with
ripening of guava.
 Bibliography
1. Practical Chemistry by Laxmi Publications
2. www.gooogle.com
3. The Family Encyclopedia by Dorling Kindersley
4. www.wikipedia .com