Khoula Abdulrahman Almuazza
42S163108

 Aim :
To extract pectin from avocado peel using oxalic acid
and citric acid.
 Objectives:
i. To study the effect of solvent to solid ratio (SSR) on
pectin yield.
ii. To study the effect of time on pectin yield.
iii. To study the effect of temperature on pectin yield.
iv. To study the effect of pH on pectin yield.
v. To study the effect of agitation speed on pectin
yield.

 Avocado:
Avocado is botanically a large berry containing a single
large seed known as a “pit” or a “stone”.
 Pectin:
Pectin is a heteropolysaccharide derived from the cell
walls of terrestrial plants. It is mainly derived from citrus
fruits, and is used as a gelling or thickening agent.

Names: M. Kratchanova, I. Panchev, E. Pavlova, L. Shtereva
Title: Extraction of pectin from fruit materials pretreated in an electromagnetic field of super-high
frequency
Journal: Carbohydrate polymers
Volume: 25
Year: 1994
Page: 141-144
Abstract:
Laboratory studies on the extraction of pectin from orange, lemon and apple wastes
pretreated in an electromagnetic field of super-high frequency were carried out. A 10-min
preliminary microwave heating (2450 MHz, 0·5 kW) of crushed fruit materials was found to
provide a higher pectin yield. The extracted pectin exhibited higher values for degree of
esterification and gel strength compared with the control sample. The effect depends on the
kind of raw material.
The favourable effect of microwave heating on the yield and quality of pectin is assumed to
be due first to the partial disintegration of the plant tissue and hydrolysis of protopectin,
and second, to the rapid inactivation of the pectolytic enzymes in the raw material. The
second hypothesis has been partly confirmed by model experiments.
The results presented can serve as a basis for improving pectin manufacturing. It is
expedient that fresh pectinous raw materials should be subjected to microwave heating
before drying.

 Raw material: Avocado.
 Chemicals: Citric acid, oxalic acid, acetone
,Ethanol and distillate water.
 Glassware's: Beaker, test tube, conical
flask, measuring cylinder, evaporating dish,
watch glass, stirring rod, funnel.
 Equipments: Cutting knife, spatula, weight
boat, filter paper, test tube rack, wash bottle,
blender, hot air oven, water bath, water bath
shaker, pH meter, centrifuge.

Collection of avocado
fruit, removing of
peel and drying.
Preparation of dried
avocado peel powder.
Dried peel powder
(100g)+70% ethanol at
80C for 5min with solid
to solvent ratio of 1:6
and decant.
Remaining sample +
absolute ethanol at
80C for (5min ,1:6) and
decent.
Remaining sample +
absolute ethanol at RT
for (5min, 1:6) and
decant, repeated for 5
times.
Remaining sample +
acetone at RT for (5
min, 1:2) and decant.
Let the remaining
alcohol insoluble
residue sample (AIR)
to dry.
Prepare oxalic acid
and citric acid of pH
1.5, 2 and 2.5 .
Prepare 3 samples in
different conical flask
of 2g AIR and adding
20 ml to each citric
acid of different PH ‘s .

Keep sample in hot water
bath shaker for 1h at 80C
and then filter.
Filtered liquids are
centrifuged for 15min at
1600 rpm.
After centrifuge measure the
volume of the liquids and add
an equal amount of 95%
ethanol (500 ml), then
centrifuge again at 1600 rpm
for 15min and decant.
After decanting, measure the
mass of an empty centrifuge
tube and a centrifuge tube +
wet pectin in order to find the
%pectin yield.
Same steps are
repeated for the
effect of solid to
solvent ratio (20ml,
30ml, and 40ml).

 To repeat the effect of pH on pectin yield.
 To study the effect of time, temperature and
agitation speed on pectin yield.

 Always wear protective lab coat in order to
protect your clothes and body.
 Gloves must be worn while handling with
chemicals.
 Also wear safety glasses and face mask to
protect you eyes from chemicals and from
inhaling them.
 After finishing the experiment clean the area
and put the equipments back in place.

 Kratchanova, M., Panchev, I., Pavlova, E., & Shtereva, L. (1994).
Extraction of pectin from fruit materials pretreated in an electromagnetic
field of super-high frequency. Carbohydrate polymers, 25(3), 141-144.