Table of Contents
ABSTRACT…………………………………………………………………………. 2
1. Introduction……………………………………………………………………..3
1.1 Background…………………………………………………………………....3
1.2 Pectin structure………………………………………………………………...3
1.3 Mango peel pectin……………………………………………………………..4
2. Results…………………………………………………………………………...6
2.1 Independent samples T-test……………………………………………………6
3. Discussion…………………………………………………………………………9
4. Conclusion………………………………………………………………………...11
5. Reference………………………………………………………………………….12
Appendix
Appendix i
Appendix ii
Appendix iii
1
Abstract
A structural hetero polysaccharide known as pectin is frequently derived from peels of some
fruits like orange, banana or mango. Due to its versatility, pectin is a material used in cosmetic,
food, and medicinal goods because of its qualities that act as a thickener. Mango peels could be
used as a source of pectin because this residue is not in use at the moment and is frequently
discarded. Approximately 20% of pectin can be found in mango peels. This study examines
different extraction techniques used to extract pectin from three mango cultivars (tommy atkins,
glenn and palmer) with the aim of identifying the best and most effective extraction technique.
The ten ripened mangos of each of the cultivars were manually peeled, carefully washed and
oven-dried at 45°C for a period of two days. Afterwards, the dried peels were ground and filtered
through a 100-mesh screen in order quality mango peel powder (MPP). The conventional hotacid extraction technique was used on the palmer, tommy atkins and glenn which gave a pectin
yield of 15.58 g/100g DM, 21.26 g/100g DM and 11.28 g/100g DM, respectively. Furthermore,
tommy atkins was subjected to two more extraction techniques in order to get the highest amount
of pectin that can be extracted. Enzyme-assisted extraction and ultrasound-assisted extraction
gave a pectin yield of 25.50g/100g DM and 30.89g/100g DM, respectively. The relatively high
pectin yield by ultrasound-assisted extraction was due to the stronger and enhanced solvent
entrance into the cells and intensification of the mass transfer caused by the collapse of
cavitation bubbles near cell walls which is induced by ultrasound waves. Hence, the application
of ultrasound-assisted technique has proven to be an efficient approach in recovering high pectin
yield from mango peels which is an excellent quality for the food sector.
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1 Introduction
1.1 Background
Mangos are members of the family Anacardiaceae's genus Mangifera. There are numerous
kinds of edible fruit-bearing plants in the genus Mangifera. The majority of mangoproducing plants are members of the Mangifera indica genus (Shah et al, 2010). Mangoes
belong to the drupe family and is most times regarded to as tropical stone fruits. There is a
seed in this pit. When the fruit shoulder broadens (or fills out) and part of the green fruit on
the tree starts to turn yellow, the crop is said to be mature (e.g. Pride, Irwin and Tommy
Atkins, etc.) (Litz, 1997).
Maria et al (2019) opine that mangoes constitute phytochemicals, vitamins, and minerals, and
macronutrients (carbohydrates, proteins, amino acids, lipids, and organic acids). They also
stated that phenolic, polyphenol, pigments, and volatile constituents can all be found in
mangoes; pectins and cellulose are also two structural carbohydrates found in mango fruit.
1.2 Pectin Structure
Pectin is a significant polysaccharide that is used in a variety of industries, including food,
pharmaceuticals, and others. It forms gel when exposed to Ca2+ ions or a solute with a low
pH, (Prakash and Priyah, 2016). Pectin is described as a glazing agent, an emulsifier,
stabilizer, gelling agent and/or thickening in commercial uses, pectin is a naturally
renewable, biodegradable, biocompatible, and occurring polysaccharide (Williams et al.,
2009).
As a fruit's primary constituent, pectin is what causes a gel to develop when heated and
combined with sugar. Pectin is typically described as water-soluble pectinic acids with varied
methyl ester concentrations that, under the right circumstances, can form gels alongside sugar
and acid. Pectin is a frequent culinary component because of its excellent gelling ability. The
neutral sugar rhamnogalacturonan, which is also present in pectin molecules, is what splits
and kinks the galacturonic acid chain (Thakur et al., 1997)
While the backbone of RG-I is made up of alternating GalA and rhamnose residues, the
backbones of HG, RG-II, and XGA are composed of -1, 4-linked galacturonic acid (GalA)
residues that can be acetylated at O2 or O3 or methyl-esterified at the C6 carboxyl group.
3
RG-II has intricate side chains, RG-I has structurally diversified side chains mostly
comprised of arabinose and galactose, and XGA is just HG with additional -1,3-xylosyl side
groups. There are at least 12 different types of sugars, (Mohnen, 2008). The figure below
structure and constituents of pectin
1.3 Mango Peel Pectin
The mango fruit has three distinct parts: the pulp (mesocarp), the skin (epicarp), and the seed
kernel (endocarp). Mango pulp is a rich source of phytochemicals such as aromatic
compounds, vitamins, polyphenols, reducing sugars, anthocyanins, amino acids and pectin,
as well as functionally active substances (Lebaka et al., 2021). The flesh (pulp) of the fruit is
consumed the most during processing, whereas the peel and seeds—which together make up
35–60% of the weight of the fruit—are typically wasted as biomass, (Larrauri et al., 1996).
The amount varies between mango kinds, but the leftovers of mango processing include peel
(5–17%) and seed (7–17%). The figure 2 below shows the biomass and composition of the
mango fruit.
4
About one-third of the dry content of higher plants' cell walls is made of pectin, a complex
mixture of polysaccharides, (Pranati and Rishabha, 2011). These chemicals are also
present in much lesser quantities in the cell walls of grasses. According to Kertesz (1951),
the middle lamella of the cell wall has the largest amounts of pectin, which gradually
decrease as one moves through the primary wall and into the plasma membrane. Although
pectin is found in abundance in the majority of plant tissues, there are just a few sources that
can be utilized in the production of pectin for commercial application. This is due to the fact
that pectin's capacity to gel depends on its molecular size and esterification level
(DE).Mango peel is an effective substitute for pectin extraction, according to Banerjee and
colleagues in 2017. The peels were also recognized as possible sources of high and low
methoxy pectin, (Banerjee et al, 2017). The successful extraction of pectin from mango peels
is made possible through the application of certain extraction techniques. These extraction
techniques are split into parts. The first part is the conventional method which is the
Conventional Hot-acid Extraction (CHE). The other part is the novel techniques which are:
Microwave-Assisted Extraction (MAE), Enzyme-Assisted Extraction (EAE), UltrasoundAssisted Extraction (UAE).
In Conventional Hot-acid Extraction (CHE), pectin is always extracted in acidified water
with 0.05–2 M sulfuric acid, phosphoric acid, nitric acid, hydrochloric or acetic acid,
between 80 and 100 °C for one hour while stirring constantly, (Georgiev, 2013). Solvent
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characteristics, temperature, solid-to-solvent ratio, pH, dry solids, particle diffusion rate and
size are only a few of the variables that affect conventional extraction, (Mari´c et al, 2018)
In Microwave-Assisted Extraction, plants molecules are exposed to microwaves, that is, it
involves dielectric heating. The microwave’s irradiation speeds up cell rupture by causing an
abrupt rise in internal pressure and temperature within the plant sample's cells. This
encourages the destruction of the sample's surface and, in turn, causes pectin to exude from
the plant cells into the surrounding solvents, increasing the risk of infection, (Maran et al,
2013).
In Enzyme-Assisted Extraction (EAE), the plant cell wall matrix is hydrolyzed by the
enzymes to enhance the extraction process. Enzymatic extraction of pectin uses cell walldegrading enzymes with minimal pectinolytic activity to hydrolyze non-pectin plant cell wall
components, (Fissore, 2009). The EAE is influenced by reaction duration, enzyme type and
concentration, pH value, temperature and plant material particle size, (Poojary et al, 2017)
Ultrasound-Assisted Extraction is specifically designed for the extraction of pectin.
Ultrasound-induced cavitation bubble collapses near cell walls which results in cell rupture.
This, however, strengthens and improves solvent entry into the cells and intensifies the mass
transfer, (Barba et al, 2015)
Subcritical Water-Assisted Extraction (SWE) is a liquid at high pressure that can reach
temperatures over its typical boiling point without changing phases. The SWE is promoted as
a green method for valuing mango peel as a pectin product.
2. Results
The dataset 1 included pectin percentage from three different mango cultivars (palmer, Tommy
Atkins and Glenn) which was extracted using conventional extraction technique. The mango
cultivar (Tommy Atkins) was then used for further extraction of pectin using novel extraction
method (dataset 2). 50 samples of mango cultivars were analyzed in total, percentage of pectin
yielded was calculated from crude pectin powder weighed.
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2.2 Independent samples T-test
The table below shows pectin yield from three different mango cultivars, using Hot-acid
extraction technique. Furthermore, the table represents the average and standard deviation of the
dataset 1 in Appendix 1, this average was gotten by the sum of dataset numbers and divided by
the total number of value in the set.
Mango cultivar
Average (g/100g DM)
Standard deviation (SD)
Palmer
15.58
2.15
Tommy Atkins
21.26
0.59
Glenn
11.28
0.97
Table 1: Pectin yield (g/100g DM) from three mango cultivar using Hot-acid extraction
technique.
The extraction from mango cultivar (Tommy Atkins) using Hot-acid extraction presented the
highest pectin yield (21.26 g/100g DM).
This confirmed that, pectin yield from mango cultivar (Tommy Atkins) using Hot-acid extraction
method, had significantly higher pectin yield comparing to mango cultivar Palmer and Glenn
pectin yield.
Figure 1 represents a comparison of pectin yield using Hot-acid extraction technique from three
different mango cultivar and shows a significant increase in pectin yield from mango cultivar
(Tommy Atkins).
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25
pectin yield (g/100g DM) of different mango cultivar
using Hot-acid extraction technique
Pectin yield (g/100g DM)
a
20
b
15
c
10
5
0
palmer
tommy atkins
mango cultivars
glenn
Figure 1: Comparison of pectin yield from different mango cultivar using Hot-acid
extraction method.
Independent samples T-test p<0.05
The table below shows pectin yield from mango cultivar (Tommy Atkins), using three different
extraction methods. This table represents the average and standard deviation (SD) of the dataset
2 attached in Appendix 1, this average was gotten by the sum of dataset numbers and divided by
the total number of value in the set
Extraction Techniques
Average (g/100g DM)
Standard Deviation (SD)
Hot-acid Extraction
21.26
0.59
Enzymatic Extraction
25.50
0.81
Ultrasound Extraction
30.89
0.35
Table 2: Pectin yield (g/100g DM) from mango cultivar (Tommy Atkins), using different
extraction techniques.
The extraction from mango cultivar (Tommy Atkins) using ultrasound extraction technique
presented the highest pectin yield (30.89 g/100g DM).
The figure below represents a comparison of pectin yield using different extraction technique
from mango cultivar (Tommy Atkins) and shows a significant increase in pectin yield using
ultrasound extraction technique.
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This confirmed that, pectin yield from mango cultivar (Tommy Atkins) using ultrasound
extraction method had significantly higher pectin yield comparing to Hot-acid and Enzymatic
extraction techniques.
pectin yield (g/100g DM) from mango cultivar(Tommy
cultivar) using different extraction techniques
35
a
30
Pectin yield (g/100g DM)
b
25
c
20
15
10
5
0
Hot-acid extraction
EAE
UAE
Extraction techniques
Figure 2: Comparison of pectin yield from mango cultivar (Tommy Atkins) using three
different extraction methods.
Independent samples T-test p<0.05
3. Discussion
On the cultivars of the glenn, Tommy Atkins, and palmer mangoes, hot-acid extraction was
applied. Pectin yields from this extraction method were 15.58 g/100 g DM, 21.26 g/100 g DM,
and 11.28 g/100 g DM, respectively. The three different mango cultivars' peels were treated to
temperature and time changes, which weaken plant cell walls and facilitate solvent diffusion and
pectin extraction (Sayah et al., 2016). High temperatures during this extraction technique also
result in a higher pectin output. Therefore, when compared to the cultivars of palmer and glenn
mango, the usual extraction method (Hot-acid) utilized on Tommy Atkins yielded a larger pectin
yield.
During the use of Hot-acid extraction technique, the pectin yield from the mango peel of tommy
atkins (mango cultivar) was 21.26 g/100g DM. However, when enzymatic extraction technique
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was applied, the pectin yielded from tommy atkins (mango cultivar) became higher (25.50
g/100g DM). This is because cell permeability increases due to disintegration of the cell wall
which is caused by hydrolyzing the matrix of the plant cell wall by enzymes used for the
improvement of pectin extraction process, (Poojary et al., 2107).
According to the result, pectin yield from the mango peel (tommy atkins) using ultrasound
extraction technique yielded significantly the highest amount of pectin (30.89 g/100g DM). This
extraction technique has proven to be very effective when extracting pectin from mango peel. In
contrast to other extraction methods, ultrasound extraction produces a high yield of pectin due to
stronger and improved solvent entry into the cells and intensified mass transfer brought on by the
cavitation bubbles' collapse near the cell walls, which is brought on by ultrasound and results in
cell disruption. (Zhu et al., 2017).
The two main phases of the hot-acid extraction method are the hydrolysis of proto-pectin into
pectin using acids and the subsequent ethanol precipitation (Djilas S et al., 2009). While the
Enzyme Assisted Extraction (EAE) technique hydrolyzes non-pectin plant cell wall components,
it also degrades plant cell walls to extract pectin utilizing pectinesterase and other enzymes with
low pectinolytic activity (Puri M et al., 2012]). Ultrasound aided extraction (UAE), in contrast to
the traditional method (hot-acid extraction), employs sound waves traveling through a liquid
medium and causing compression and expansion. As a result, cavitation—the formation,
expansion, and burst of bubbles occurs. As a result, unstable microscopic bubbles with high
temperatures and pressure might occur, which alter the plant matrix and improve the extractor
solvent's ability to penetrate it, (Wang et al., 2015) .
As effective as the ultrasound extraction method was for extracting pectin in this
experimentation, it has the drawback of not being able to significantly minimize the need for
solvent. Additionally, it improves the yield and kinetics during the recovery of pectin and
reduces the time required for extraction, the amount of energy used, and the amount of solvent
used (Adetunji et al., 2017). Benefits of the enzyme extraction method include the utilization of
high temperatures and absence of acidic pH levels during the extraction. it also doesn't have a
corrosive effect on the machinery used in the process, doesn't require any special pre-treatment
processes, speeds up and cuts down on the amount of time needed for extraction, improves
pectin quality due to the mild conditions of enzymatic extraction (Ptichkina et al., 2008). The
method has a disadvantage in that the enzyme required for it is expensive, and the way each
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enzyme reacts differently to environmental changes makes it challenging to scale up the
enzymatic extraction process. (Puri et al., 2012).
According to numerous studies, pectin can deteriorate quickly during hot-acid extraction due to
its high sensitivity and vulnerability to acid [Mollea C et al., 2008]. Environmental issues and the
loss of an unknown quantity of volatile chemicals, according to Yang et al. (2018), are other
downsides of the traditional extraction method (hot-acid extraction). However, due to increased
affinity for the cation Ca2+, which stabilizes the pectin molecule, conventional extraction has the
ability to precipitate pectin. (Chan et al, 2013).
4. Conclusion
Around one-quarter of the mango fruit's total weigh is made up of peels. From this biomass,
mango peel pectin may be extracted. From the experiment conducted on three mango cultivars
(tommy atkins, glenn and palmer), the extraction of pectin varies when subjected to either the
conventional or novel extraction techniques. This study has dealt with a variety of mango
cultivar and has discovered that pectin can be obtained readily from all the cultivars, but
excellent quality and yield is dependent on a few key sources. Hence, many extraction
techniques were used and have reported various yield percentages, but the Ultrasound-assisted
extraction technique is still the most trustworthy.
An efficient extraction method has been demonstrated to be the use of ultrasound. As a result,
this study adds to the body of evidence that the ultrasound technique always requires a short
amount of time compared to other methods to successfully extract pectin. The pectin extraction
yield was positively impacted by the mangoes' state of maturity, creating the possibility of using
mangoes as a source of pectin that would never be commercially viable and reducing waste at
this stage of production. The advantage of using ultrasound extraction technology is that it has a
minimal negative influence on the environment and can be done more quickly. As a result, using
this technique to remove pectin from mango peels or other waste products from the agricultural
business could be successful.
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