Study of presence of
Oxalate ions
In
Guava Fruit
At different stages of ripening
Made By:
Mahak Shah
XII-A
Certificate
This is to certify that PRITENDRA SINGH TIWARI class 12th
KENDRIYA VIDYALAYA NO.2 REWA [M.P] . 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 uo to my expectation and as per
the guidelines by CBSE..
Signature of guide
[MISS.SEEMA TAMRAKAR}
Signature of principle
[DR.AJAY SINGH]
INDEX
S.No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Topic
Acknowledgement
Introduction
Plant Chemicals
Oxalic Acid
Experiment
Observations
Calculations
Conclusion
Bibliography
Page
4
5
6
8
9
11
12
13
14
ACKNOWLEDGEMENT
At the outset , I express my heartiest gratitude to
my guide “MISS.SEEMA TAMRAKAR” 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.
2.
3.
4.
5.
for dysentery (bacterial and amebic), diarrhea, colic, and
infantile rotavirus enteritis
as a broad-spectrum antimicrobial for internal and
external bacterial, fungal, candidal, and amebic
infections
to tone, balance, protect and strengthen the heart (and
for arrhythmia and some heart diseases)
as a cough suppressant, analgesic (pain-reliever), and
febrifuge (reduces fever) for colds, flu, sore throat, etc
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 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 colour.
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.
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
60C 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
Concordant
Guava
readings
volume of
extract from Initial Final
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
=
(guava extract)
N1 x 20 =
N2V2
(KMnO4 solution)
xV
 Normality of oxalate, N1 =
Strength of oxalate = Normality x Eq. mass of oxalate ion
=
Guava
extract
from
Fresh
1 day old
2 day old
3 day old
x 44 g/litre of the diluted extract.
Strength of
oxalate ion
(g/litre)
5.5
3.3
1.65
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