Study of
presence of
Oxalate
ions
In
Guava
Fruit
At different stages of
ripening
Made By:
Arnav Jaiswal
XII-A
Certificate
This is to certify that ARNAV JAISWAL of class
12th from RAMDOOT INTERNATIONAL SCHOOL,
GHAZIPUR
has successfully completed his project work in
chemistry on the topic-
“PRESENCE OF OXALATE IONS IN GUAVA FRUIT AT
DIFFERENT
STAGES OF RIPENING”
HE has taken proper care and shown at most
sincerity in completion of this project to my
expectation and as per the guidelines by CBSE.
Signature of guide Signature of
principle
INDEX
S.No Pag
. Topic e
1. Acknowledgement 4
2. Introduction 5
3. Plant Chemicals 6
4. Oxalic Acid 8
5. Experiment 9
6. Observations 11
7. Calculations 12
8. Conclusion 13
9. Bibliography 14
ACKNOWLEDGEMENT
At the outset , I express my heartiest
gratitude to my guide “MR. ANUP
PRESAD” for the divine guidance and
wisdom showered on me to undertake
this project.
I am immensely
grateful to my beloved Principal for
his involvement in this project by
providing useful inputs and timely
suggestion.
My parents also played
a key role in shaping up this project
nicely and I convey my special thanks to
them as well.
INTRODUCTION
Family: Myrtaceae
Genus: Psidium
Species: guajava
Common names: Guava, goiaba,
guayaba, djamboe, djambu, goavier,
gouyave, goyave, goyavier, perala,
bayawas, dipajaya jambu, petokal,
tokal, guave, guavenbaum, guayave
banjiro, goiabeiro, guayabo, guyaba,
goeajaaba, guave, goejaba, kuawa,
abas, jambu batu, bayabas, pichi, posh,
enandi
Part Used: Fruit, leaf, bark
Guava is a common shade tree
or shrub in dooryard gardens in
the tropics. It provides shade
while the guava fruits are eaten
fresh and made into drinks, ice
cream, and preserves. In the
richness of the Amazon, guava
fruits often grow well beyond the
size of tennis balls on well-
branched trees or shrubs
reaching up to 20 m high.
Cultivated varieties average
about 10 meters in height and
produce lemon-sized fruits. The
tree is easily identified by its
distinctive thin, smooth, copper-
colored bark that flakes off,
showing a greenish layer
beneath.
Guava fruit today is considered
minor in terms of commercial
world trade but is widely grown
in the tropics, enriching the diet
of hundreds of millions of people
in the tropics of the world.
Guava has spread widely
throughout the tropics because
it thrives in a variety of soils,
propagates easily, and bears
fruit relatively quickly. The fruits
contain numerous seeds that
can produce a mature fruit-
bearing plant within four years.
PLANT CHEMICALS
Guava is rich in tannins, phenols,
triterpenes, flavonoids, essential
oils, saponins, carotenoids, lectins,
vitamins, fiber and fatty acids.
Guava fruit is higher in vitamin C
than citrus (80 mg of vitamin C in
100 g of fruit) and contains
appreciable amounts of vitamin A
as well. Guava fruits are also a
good source of pectin - a dietary
fiber. The leaves of guava are rich
in flavonoids, in particular,
quercetin. Much of guava's
therapeutic activity is attributed to
these flavonoids. The flavonoids
have demonstrated antibacterial
activity. Quercetin is thought to
contribute to the anti-diarrhea
effect of guava; it is able to relax
intestinal smooth muscle and
inhibit bowel contractions. In
addition, other flavonoids and
triterpenes in guava leaves show
antispasmodic activity. Guava also
has antioxidant properties, which is
attributed to the polyphenols found
in the leaves.
Guava's main plant chemicals
include: alanine, alpha-humulene,
alpha-hydroxyursolic acid, alpha-
linolenic acid, alpha-selinene,
amritoside, araban, arabinose,
arabopyranosides, arjunolic acid,
aromadendrene, ascorbic acid,
ascorbigen, asiatic acid, aspartic
acid, avicularin, benzaldehyde,
butanal, carotenoids, caryophyllene,
catecholtannins, crataegolic acid, D-
galactose, D-galacturonic acid,
ellagic acid, ethyl octanoate,
essential oils, flavonoids, gallic acid,
glutamic acid, goreishic acid,
guafine, guavacoumaric acid,
guaijavarin, guajiverine, guajivolic
acid, guajavolide, guavenoic acid,
guajavanoic acid, histidine, hyperin,
ilelatifol isoneriucoumaric acid,
isoquercetin, jacoumaric acid,
lectins, leucocyanidins, limonene,
linoleic acid, linolenic acid, lysine,
mecocyanin, myricetin, myristic acid,
nerolidiol, obtusinin, octanol,
oleanolic acid, oleic acid, oxalic acid,
palmitic acid, palmitoleic acid,
pectin, polyphenols, psidiolic acid,
quercetin, quercitrin, serine,
sesquiguavene, tannins, terpenes,
and ursolic acid.
GUAVA PLANT SUMMARY
Main Preparation Method: decoction
Main Actions (in order): antidysenteric,
antiseptic, antibacterial, antispasmodic,
cardiotonic (tones, balances, strengthens the
heart) Main Uses:
1. for dysentery (bacterial and amebic), diarrhea,
colic, and infantile rotavirus enteritis
2. as a broad-spectrum antimicrobial for internal
and external bacterial, fungal, candidal, and
amebic infections
3. to tone, balance, protect and strengthen the
heart (and for arrhythmia and some heart
diseases)
4. as a cough suppressant, analgesic (pain-
reliever), and febrifuge (reduces fever) for
colds, flu, sore throat, etc
5. as a topical remedy for ear and eye infections
Properties/Actions Documented by Research:
amebicide, analgesic (pain-reliever), antibacterial,
anticandidal, antidysenteric, antifungal, antimalarial,
antioxidant, antispasmodic, antiulcerous,
cardiodepressant, cardiotonic (tones, balances,
strengthens the heart), central nervous system
depressant, cough suppressant, gastrototonic (tones,
balances, strengthens the gastric tract), hypotensive
(lowers blood pressure), sedative, vasoconstrictor
Other Properties/Actions Documented by Traditional
Use: anti-anxiety, anticonvulsant, antiseptic,
astringent, blood cleanser, digestive stimulant,
menstrual stimulant, nervine (balances/calms nerves),
vermifuge (expels worms)
Cautions: It has a cardiac depressant effect and is
contraindicated in some heart conditions.
OXALIC ACID
IT is the chemical compound
formula H2C2O4. This dicarboxylic
acid is better described with the
formula HO2CCO2H. It is a relatively
strong organic a cid, being about
10,000 times stronger than acetic
acid. The dianion, known as
oxalate, is also a reducing agent
and a ligand in coordination
chemistry. Oxalic acid and oxalates
are abundantly present in many
plants, most notably in sour grass,
and sorrel (including Oxalis), roots
and leaves of rhubarb and
buckwheat.
At high concentrations, it is a
dangerous poison, but such
immediately toxic levels are not
found in foodstuffs but rather in
manufactures, such as some
bleaches, some anti-rust products,
and some metal cleaners (among
other things). It is also a naturally
occurring component of plants, and
is found in relatively high levels in
dark-green leafy foods
In the human body, ingested oxalic acid is
not a useful nutrient; so, like all such
unneeded components of diet, it is
processed by the body to a convenient form
and that byproduct is then excreted-
In the human body, ingested oxalic
acid is not a useful nutrient; so,
like all such unneeded components
of diet, it is processed by the body
to a convenient form and that
byproduct is then excreted-in this
case, in the urine. In the course of
being processed by the body,
oxalic acid combines with other
substances to form various salts,
called oxalates; usually, those salts
are in solution, but in high
concentration some may
precipitate out in crystalline form.
Such tiny crystals can cause
damage to human tissue,
especially to the stomach, the
kidneys, and the bladder. It is
commonly believed that oxalates
contribute to the formation of
kidney and bladder stones; one
common nutrient with which oxalic
acid combines is calcium, making
the salt calcium oxalate, and
calcium oxalate is found in kidney
stone
To study the presence of
Oxalate Ion content in Guava
Fruit at different stages of ripening
Requirements:100 ml measuring flask, pestle
and mortar, beaker, titration flask, funnel,
burette, weight box, pipette, filter paper, dilute
H2SO4, KMnO4, and guava fruits at different
.
stages of ripening
Theory: Oxalate ions are extracted from the
fruit by boiling pulp with dil. H2SO4. Then
Oxalate ions are estimated volumetrically by
titrating the solution with standard KMnO4
solution.
End Point: Appearance of permanent pink
color.
Procedure:
1. 50.0g of fresh guava was weighed and crushed to
a fine pulp using pestle-mortar.
2. The crushed pulp was transferred to a beaker and
about 50ml dil.
3. H2SO4 was added. The contents were boiled for
about 10 minutes. 3. The contents were filtered
and cooled in 100ml measuring flask. The volume
was made up to 100ml by adding distilled water.
4. 20ml of this solution was taken into a titerating
flask and 20ml of dil. H2SO4 was added to it. The
mixture was heated to about 60C and titerated
against the standard KMnO4 solution taken in a
burette
5. The process was repeated with different samples
of guava.
OBSERVATION
Weight of guava taken = 50.0 g
Volume of guava extract taken =
20.0 ml
Normality of KMnO4 solution =
Burette Concorda
Guava readings nt
extract volume of
Initial Final
from KMnO4
Solution
used
Fresh 0 50 50
1 day old 0 30 30
2 day old 0 15 15
3 day old 0 9 9
Calculations
N1V1 = N2V2
(guava extract) (KMnO4 solution)
N1 x 20 = xV
Normality of oxalate, N1 =
Strength of oxalate = Normality x Eq. mass of oxalate
ion
= x 44 g/liter of the diluted extract.
Strength
Guava of oxalate
extract ion
from (g/liter)
Fresh 5.5
1 day
old 3.3
2 days
old 1.65
3 days
old 0.99
Conclusion
Oxalic acid and oxalates are
abundantly present in many
plants, most notably in sour
grass, and sorrel (including
Oxalis), roots and leaves of
rhubarb and buckwheat.
After doing this
experiment, we can
conclude that unripe guava
has a high content of
Oxalate ions. The
concentration of oxalate
ions decreases with the
ripening of fruit.
BIBLIOGRAPHY
In order to complete this project, I took
help from:
My chemistry teacher
Comprehensive Practical
Chemistry
(Lab Manual) of Laxmi Publication
Different internet sites:
www.google.com
www.rain-tree.com
www.wikipedia.com
