pectin from durian peels as metal biosorben

1. THE UTILIZATION OF PECTIN BIOMATERIALS FROM DURIAN
(Durio zybhetinus) PEELS AS METAL BIOSORBENT
Khalisa Aini Sinaga, Dewi Nur Halimah, Siti Mudhakiroh, Nur Sabrina
Hasyyati
Biology, Science and Mathematic Faculty, Diponegoro University, Indonesia
Email. khalisa.aini@yahoo.com, PH. 085727246544
ABSTRACT
Heavy metal pollution is very harmful for the environment. Many reports have
shown the facts about the dangerous of environmental pollution, especially by heavy
metals in waters, whether as a result of the use of water for daily consumption as well as
waste water consumption and freshwater biota that live in the polluted waters.
Considering the bad effects of heavy metal pollution to our environment, our solution is
the utilization of pectin from waste durian peels as heavy metals biosorbent, so it can be
used to overcome the environmental pollution caused by heavy metals especially copper
and zinc. Pectin biomaterial from durian peels is an alternative biomaterial that can be
chosen because it has a minimal cost in the production process.Pectin is one of the
biomaterials that can be used as metal absorbent. Carboxylate groups of pectin can bind
the metal complex compounds that are not soluble in the water. In this research, copper
and zinc assay are obtained by using atomic absorption spectrophotometry. The research
methods are done in several steps including durian peels sorting, washing,
homogenization, heating, filtrating, washing with ethanol, drying in the oven, and
sieving. Results which are obtained have shown that the pectin biomaterial from waste
durian peels able to absorb Cu (Cu Absorbance) of 25.9% and able to absorb Zn
(Absorbance Zn) of 74.7%.
Keywords: Pectin, Durian Peel, biosorbent, Heavy Metal.
INTRODUCTION
Nowadays, heavy metal pollution becomes one of the main problems that
have to be overcome, because it is very dangerous for the environment. This case
was first reported in Japan, related disease of "itai-itai" which causes the
fishermen and their families were suffering from chronic intoxication due to
cadmium heavy metals and gave an impacts in the death of 100 people
(Soemirat, 2005). The best solution to overcome the environmental pollution due
to heavy metals is utilizing biomaterials as metal biosorbent. Biomaterial is
chosen as an alternative solution because of the cheaper price to be produced than
another solution. One of biomaterials that can be used as metal absorbent is
pectin. Carboxylate groups of pectin can bind to the metal.

2. Durian (Durio zibhetinus) is provided too much in Indonesia. Durian is
one of fruits which have very typical aroma, not only that but also having the
delicious taste of durian which makes a lot of people like to consume.
Unfortunately, the peels and seeds of durian were just thrown away as the organic
waste. Durian fruits contain 20-35% of pectin, while the peels contain 60-75%
of pectins, and the seeds contain 5-15% of pectin, so that it can absorbs the heavy
metal pollution, especially that caused by copper and zinc (Djaeni, 2010 ).
Considering about environment problems, our research is using pectin
biomaterials from durian peels as a heavy metal biosorbent. This research
analyzed about the absorption of pectin derived from durian peels to absorb the
heavy metal pollution. It is an alternative biomaterial that can be chosen because it
has a minimal cost in the production process and the method is simple.
METHODS
The research was conducted in Biology Laboratory, Science and
Mathematic Faculty, Diponegoro University. The research had done by using
a quantitative approach by gathering the pectins, and also by calculating the
absorbance.
1. Equipments and Materials
The equipments which are used such as: fume hoods, heating pads,
magnetic stirrer, kitchen knives, blander, drying cabinet, thermometer 100 ° C,
spatula, filter paper, centrifugation, beaker, erlenmeyer, test tubes, measuring
cup, beaker , and the petri dish. While the materials which are used: durian
peels, aquadest, 10 mmol / L CuSO4 solution, 10 mmol / L ZnSO4 solution,
1N HCl, 3N HCl, 4% HCl, 2N NaOH, Ethanol 95%, standard solution of
copper (Cu) 1000 ppm and a standard solution of zinc (Zn) 1000 ppm.
2. Steps
460 g mesocarp of durian peels were mixed with 4.14 mL aquadest
and pulverized using a blender. Then it was added with 1N HCl solution to pH
2, then heated at 90 ° C during 4 hours. Then filtered it using a filter paper.
The filtrate was taken and cooled at room temperature and 13.36 mL ethanol
was added and waited for 1 hour. Then filtered it using a filter paper in order

3. to obtain part of the gel which was added with 1.28 L aquadest, then added 3
mL of 95% ethanol and filtered it by using a filter paper. It resulted wet
pectin. Wet pectin was dried at 25 ° C. The dry pectin was finely crushed and
sieved it using a mesh 60.
RESULTS AND DICUSSIONS
Durian peels are usually discarded as waste which is considered as waste
that is not useful. This happens because people don’t know durian peels still have
economic value while we know the benefits of it. Durian peels can be used as a
source of pectin which is also called the mesocarp of Durian. According to Wong
et al (2008), pectin has an ability to absorb the heavy metals such as copper and
zinc. Pectin can be extracted by heating during 4 hours at 90 ° C with the addition
of hydrochloric acid to a pH of 2. The filtrate is precipitated with ethanol using
acid (HCl 4% in 95% ethanol) and then wash it using 95% ethanol.
Analizyng about the using of pectins from durian peels as a heavy metal
biosorbent. The results showed that the pectin from durian peels able to absorb Cu
(Cu Absorbance) of 25.9% and able to absorb Zn (Absorbance Zn) of 74.7%.
Based on theose results which are obtained can be seen that the biomaterial pectin
from waste durian peels are more effectively used as an alternative to overcome
the problem of Zn heavy metal pollution. Kupchik et all (2005) said that the
pectin has an ability to absorb the heavy metals such as copper and zinc.
Dgalakturonat acid residues form at most of the molecules, in a separate area of
'smooth' and rambuty'. Metal bonding process for pectin occurs because of the
carboxylic groups of pectin which can react to form a complex compound
between pectin with copper metal.
CONCLUTION
Pectin biomaterials from durian peels can be used as heavy metals
biosorbent such as copper and zinc. Pectin from waste durian peels able to absorb
Cu (Cu Absorbance) of 25.9% and able to absorb Zn (Absorbance Zn) of 74.7%.

4. LITERATURE CITED
Djaeni, A. P. (2010). Durian seed viability as an alternative material aspects of
nutrition and economics techno. Riptech Journal, Vol. 4,. Page: 37-45.
Kuphick, L.A., Kartel, N.T., Bogdanov, E.S., Bogdanova, O.V., Kuphick, M.p.
(2005). Chemical Modification of Pectin to Improve it Sorption Properties.
Russian Journal od Applied Chemistry. National University of Alimentary
Technologies. Kiev. Ulkraine. Vol.79. No. 3. Page. 457.
Soemirat, S. 2005. Environtment Health. Gajah Mada University Press.
Yogyakarta.
Wong, W.W., Abbas F.M.A., Liong, M.T., Azhar, M.E., 2008, Modification of
Durian Rind Pectin for Improving Biosorbent Ability, International Food
Research Journal 15(3), 363-365.