Biodegradable Packaging Film From Banana Peel
INTRODUCTION:
Today’s
plastics are designed with little consideration for their ultimate
disposability or recyclability. This has resulted in mounting worldwide
concerns over the environmental consequences of such materials when they enter
the waste stream after their intended uses, Of particular concern are polymers
used in single use, disposable plastic applications. Plastics are strong,
light-weight, inexpensive, easily processable and energy efficient. They have
excellent barrier properties. They are disposable, and very durable. However,
it is these very attributes of strength and indestructibility that cause
problems when these materials enter the waste stream. They are not readily
broken down by the natural elements in the environment or in waste management
infrastructures such as composting to become a part of the biological carbon
cycle of our ecosystem. This results in an irreversible build-up of these
materials in the environment causing scaring of landscapes, fouling of beaches,
and posing a serious hazard to marine life. Plastics are resistant to
biological degradation because microorganisms do not have enzymes capable of
degrading and utilizing most man made polymers. In addition, the hydrophobic
character of plastics inhibits enzyme activity and the low surface area of plastics
with their inherent high molecular weight further compounds the problem.
Biodegradable
plastics are a new generation of polymers emerging on the world market.
Biodegradable plastics have an expanding range of potential applications, and
driven by the growing use of plastics in packaging and the perception that
biodegradable plastics are ‘environmentally friendly’, their use is predicted
to increase. However, issues are also emerging regarding the use of
biodegradable plastics and their potential impacts on the environment and
effects on established recycling systems and technologies. The banana fruit’s
peel was selected for this experiment because it is a waste material rich of
starch
According to
The Packaging Bulletin Magazine’s January issue, it is a proven fact that
starch and cellulose are important raw materials used in the biodegradable
plastic industry (Packaging Bulletin, 2009). Since they are rich with starch
and this starch is very easy to extract, potatoes are the most commonly used
raw materials. For this experiment we use different type of material that is
banana peel because it also rich with starch. Actually, banana peel has no
scientific name because only living organisms could have it. Banana could have
the scientific name of common banana that is Musaceae musa. The propane-1, 2,
3-triol used in the experiment functions as a plasticizer, an additive used to
develop or improve the plasticity of a material. It disconnects the polymer
chains from one another; restraining them from becoming rows of chains and
acquiring a crystalline structure. The formation of the crystalline structure
is undesired because it is a brittle and fragile structure which makes the
plastic brittle and fragile as well. Instead of the crystalline structure, the
formation of film (not becoming rows of chains of polymers) is desired.
Starch consists of two different types of polymer chains, called
amylose and amylopectin, made up of adjoined glucose molecules. The
hydrochloric acid is used in the hydrolysis of amylopectin, which is needed in
order to aid the process of film formation due to the H-bonding amongst the
chains of glucose in starch, since amylopectin restricts the film formation.
The sodium hydroxide used in the experiment is simply used in order to
neutralize the pH of the medium. .
(Manimaran@all2016)
Banana peel content
|
Item |
Content (g/100 g dry matter) |
|
Protein |
8.6±0.1 |
|
Fat |
13.1±0.2 |
|
Starch |
12.78±0.9 |
|
Ash |
15.25±0.1 |
|
Total Dietary Fat |
50.25±0.2 |
METHODOLOGY:
Banana peels are removed using
stainless steel knife and converted into small pieces. Then peels are dip in
sodium metabisulphite (0.2M) solution for 45 minutes. It is used as antioxidant
and preservative. This would increase the biodegradation period of plastic.
Banana peels are boiled in distilled water for about 30 minutes now left to dry
on filter paper for about 30 minutes.
After the peels are dried, they are
placed in a beaker and using a hand blender, the peels are pure until a uniform
paste is formed.
25gm of banana paste is placed in a
beaker.3ml of (0.5 N) HCl is added to this mixture and stirred
using glass rod.2ml Plasticizer
(Glycerol) is added and stirred. 0.5 N NaOH is added according to pH desired,
after a desired residence time. The mixture is spread on a Ceramic tile and
this is put in the oven 120C and is bake. The tile is allowed to cool and the
film is scraped off the
surface. (Y. J.
Chen-2014)
MECHANISM:
The hydrochloric acid is used in the
hydrolysis of amylopectin, which is needed in order to aid the processof film
formation due to the H-bonding amongst the chains of glucose in starch, since
amylopectin restricts the film formation. The sodium hydroxide in the
experiment is simply used
to neutralize the pH of the medium. Acid
hydrolysis changes the physiochemical properties
of starch without changing its granule
structure. If the amylopectin content is higher in the starch, the recovery of
starch decreases .Plasticizers or dispersants are additives that increase
theplasticity or fluidity of a material. The dominant applications are for
plastics, especially polyvinyl chloride (PVC) glycerol, sorbitol. The sodium
metabisulfite (Na2S2O5) is used as an
antioxidant here. It prevents the microbial growth in the peels. (Y. J. Chen-2014)
ANALYSIS:
As 0.5N solution was not accurate for
maintaining neutral Ph level we used 0.1N and 0.3N of HCl and NaOH respectively.
The tensile strength for sample keeps
increasing when the residence times are increased from 5 minutes to 15 minutes
and reaches a maximum at 15minutes and then starts decreasing when the time is
increased to 20 minutes. This suggests that the optimum hydrolysis time is 15
minutes for this sample set. Bioplastic
film can sustain the weight near about 2 kg and which have enough tensile strength.
The bioplastic prepared from banana peels that can be used as packaging
material or as a carrying bag.Glycerol is added as plasticizer that increases
its flexibility. 5.To prevent growth of bacteria and fungi sodium meta
bisulphite is used. (Y. J. Chen-2014)
PROPERTIES:
Thickness The
thicknesses of banana starch film (BSF) incorporated with banana peel extract
with different concentrations in comparison with polyvinyl chloride (PVC) film
are presented in Table 1. Significant differences in thickness were observed
between BSF and PVC film (p < 0.05). The BSF was four times thicker than the
PVC film. PVC film had a thickness value of 0.010 mm, while the BSF had a
thickness value range of 0.030–0.047 mm. This result also showed that when the
concentrations of banana peel extract increased, the film thickness was also
increased.
For packaging
films, good mechanical properties such as TS and EAB are required for the films
to resist external stress and maintain their integrity, as well as to act as
barriers during the packaging process. The mechanical properties of the BSF
incorporated with banana peel extract at different concentrations in comparison
with PVC film were expressed in terms of TS and EAB. The BSF had a slightly
decreased TS (43–31.20 MPa) and EAB (9.66–15.63%) when the banana peel extract
was added, but no significant difference was observed in EAB (p > 0.05). The
addition of glycerol to the film forming solution (FFS) significantly affected
the TS of the BSF.
The melting
temperature (Tm) and enthalpy (∆H) of the BSF incorporated with different
concentrations of banana peel extract are shown in Table 1. The Tm and ∆H of
the BSF incorporated with banana peel extract were in the range of 89.83–98.50
◦C and 192.30–273.90 J/g, respectively. Additionally, lower enthalpy values
(∆H) associated with the glass transition have been related to the weakening of
the inter- and intra-molecular interactions between starch–starch chains [24].
The thermal properties of banana starch film were markedly affected by the
concentration of banana peel extract used.
(Balavairavan, B., &
Saravanakumar, S. S. (2021).
The
appearances of the BSF incorporated with banana peel extract at different
concentrations in comparison with PVC film are shown in Figure 1. The lightness
(L*), redness/greenness (a*) and yellowness/blueness (b*) values were
significantly different when observed between the BSF and PVC film (p <
0.05). The results showed that the color attribute of the BSF had slightly
increased L* and b* values when the banana peel extract content increased from
0 to 5 (%, w/v), but no significant difference was observed in b* value (p >
0.05). The a* value of the BSF was slightly decreased because of the browning
color of the peel extract. According to the composition of banana peel, which
consists of sugar and amino acid, powder preparation using an oven drying browning
reaction may result in a dark brown color. When compared with PVC film, the BSF
containing banana peel extract had slightly lower lightness, while redness and
yellowness showed higher values than PVC film. These results are similar to
those reported by Gutierrez et al. [20], which confirmed that films with higher
amylose content are more opaque. According to these findings, it can be
concluded that the addition of banana peel extract in the BSF might limit the
use of the film only in packaging such as pouch bags for oil.
(Balavairavan, B., &
Saravanakumar, S. S. (2021).
The
antimicrobial activity of the BSF incorporated with banana peel extract at
different concentrations is shown in Figure 2. The control film and the BSF at
a concentration of 1 (%, w/v) banana peel extract did not show any inhibitory
activity against Gram-negative bacteria (E. coli O157: H7) and Gram-positive
(S. aureus TISTR 1466) food borne pathogenic bacteria. On the other hand, the
BSF at the concentration of 3 and 5 (%, w/v) banana peel extract presented
inhibition activity only against E. coli (O157: H7), and the value of the
inhibition zone area ranged between 0.1 and 0.2 mm, respectively.
(Taweechat@all2021)
TESTINGS:
Degradation test
The biodegradation test was recorded in the Figure 1 as the amount of glycerine against the mass of the biodegradable plastic mould. Based on figure 1, it shown that the amount of glycerine increases so the degradation of plastic also much quicker. The amount of glycerine mixed is very important in making biodegradable plastic it gives elasticity and make the biodegradable plastic easy to degrade. As the graph stated that Initial weight have been taken is 100 gram with different amount of glycerine that is 20ml, 25ml and 30ml was used in biodegradable plastic. 30 ml of glycerine is faster degrade than the 25ml and 20 ml of glycerine. As the biodegradation test happens the darkening of the plastic suggested decay.
Elongation test
The elongation test on
biodegradable plastic. As the figure 2 showing the initial length of the
biodegradable plastic is 4.5cm and after it been stretched it become 6.5 length
where it is the maximum strength of the biodegradable plastic that has been made.
The strength of a strip of plastic is technically the force it can bear, under
tension, per unit cross sectional area of the film, without breaking.
Mechanical properties test
A biodegradable composite film must withstand
the normal stress encountered during its application. Elongation at break
indicates the flexibility and stretch of the biodegradable composite films
which determined at the point when the composite film breaks under tensile
strength. The elongation at break value increased as the amount of starch
increased. The elongation at break values was increased due to the decreased of
banana peel starch crystallinity in the banana peel starch films. Moreover, the
introduction of plasticizer (glycerol) into the films also resulted in higher
elongation values as these decrease the intermolecular attractive force,
improving the films flexibility and extensibility. (Manimaran@all2016)
CONCLUSION:
Food packaging
functions to reduce the rate of gas transfer between food and the environment
and the control of oxygen and water vapor permeability allow the extension of
the shelf life of foods [1]. The use of packaging from synthetic plastics
causes serious environmental problems, giving rise to a demand for packaging
alternatives from biodegradable materials. The disposal of synthetic packaging
is difficult because it is non-degradable and non-recyclable, thus taking a
long time to break down. Therefore, the use of biodegradable packaging
materials can solve this problem to obtain environmentally friendly ones, which
can be made from natural polymers such as proteins, lipids, and
polysaccharides. Among polysaccharides, starch has received special attention;
it is abundant, cheap, biodegradable, edible, and renewable [2–4]. Starch is an
agricultural biopolymer found in a variety of plants including wheat, corn,
rice, beans, potatoes, etc. However, a literature search via Scopus during the
last sixteen years (2006–2021) found that the film made of banana starch
already published only five research papers [2,5–8], and all of these mostly
focused on characterization and the banana starch was not green Cavendish spp.
The effectiveness and the applicability of the banana starch film on perishable
food products were not found. Bananas are one of the major fruit crops in
Thailand. It is a commonly consumed fruit and, worldwide, banana production
reached a record of 114 million tonnes in 2017, up from around 67 million
tonnes in 2000 (Food and Agriculture Organization: FAO, 2021). In Chiang Rai,
about 4 tons per day of harvested green banana (Cavendish spp.) is wasted, and
all rejected green bananas are normally disposed improperly. Therefore,
preparing edible films from banana starch is an alternative for using this raw
material to provide a benefit. The entire banana fruit is rich in bioactive
compounds, such as phenolic constituents, carotenoids, vitamins, and dietary
fiber [9,10]. Unripe banana naturally consists of more than 70% starch, with
the remainder being protein, lipid, and fiber [11,12]. The polysaccharides in
banana powder give extra hydrogen bonding contacts between polymer chains,
which is responsible for the film-forming capacity [13]. In addition, banana
starch can be used as a base material for preparing the biodegradable film with
good gas barrier properties as well as nontoxic properties [8,14]. The
incorporation of natural active agents into edible film can be used instead of
chemical agents, which can improve the functional properties of film as well as
maintain the quality of food. Banana peel has stronger antioxidant activity,
greater phenolic compounds, and a higher mineral content than banana pulp.
Additionally, banana peels were evaluated as having powerful antimicrobial
activity against bacteria, fungi, and yeast [8,15–17]. Bioactive compounds such
as flavonoids, tannins, phlo batannins, alkaloids, glycosides, and terpenoids
are present in banana peel [15]. According to these reports, the incorporation
of these into banana starch based film was not found, as well as the
application of the developed film in the food system. (Taweechat@all2021)
BIBLIOGRAPHY:
- Balavairavan, B., & Saravanakumar, S. S. (2021). Characterization of ecofriendly poly (vinyl alcohol) and green banana peel filler (GBPF) reinforced bio-films. Journal of Polymers and the Environment, 29, 2756-2771.
- Chodijah, S., Husaini, A., & Zaman, M. (2019, February). Extraction of pectin from banana peels (musa paradiasica fomatypica) for biodegradable plastic films. In Journal of Physics: Conference Series (Vol. 1167, No. 1, p. 012061). IOP Publishing.
- Manimaran, D. S., Nadaraja, K. R., Vellu, J. P., Francisco, V., Kanesen, K., & BinYusoff, Z. (2016). Production of biodegradable plastic from banana peel. Petrochem. Eng, 1, 1-7.
- Taweechat, C., Wongsooka, T., & Rawdkuen, S. (2021). Properties of banana (Cavendish spp.) starch film incorporated with banana peel extract and its application. Molecules, 26(5), 1406.
- Y. J. Chen,” Bio plastics and their role in achieving global sustainability”, J. Chem. Pharm. Res., vol.6 (1), pp.226- 231, 2014·
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