EXTRACTION OF STARCH FROM BANANA (Musa Sapientum ) PEEL TO PRODUCE BIOPLASTIC
SUBMITTED BY: BSChE 3-1 3-1 Group 4 Manzano, Mikaela Gail Santos, Princess Gabrielle C. Valdez, Loisroi R. Yepes, Anna Lyn G.
SUBMITTED TO: Engr. Milagros Cabangon Instructor
December 2016
CHAPTER I INTRODUCTION I.
BACKGROUND OF THE STUDY
From cars to food wrap, you can make anything and everything from plastics — unquestionably the world's most versatile materials. But there's a snag. Plastics are synthetic (artificially created) chemicals that don't belong in our world and don't mix well with nature. Public pressure to clean up has produced plastics that seem to be more environmentally friendly. Bioplastics are plastics derived from renewable biomass sources, such as vegetable fats and oils, corn starch, or microbiota. Bioplastic can be made from agricultural by-products and from used plastic bottles and other containers using microorganisms. Bioplastics can be composed of starches, cellulose, biopolymers, and a variety of other materials. The demand to produce environment friendly material is increasing. The rising concern towards environmental problems brought by petroleum-based products inspired the development of the eco-friendly materials. Bioplastics are derived from agricultural resources and biomass feedstock that are renewable and therefore comply with materials that are eco-efficient and sustainable. Among the biopolymer matrices being utilized to produce bioplastics, starch is considered the most widely used material. Starch-based plastics have been projected to comprise the largest production capacity amounting to 1.3 Mt in 2020 while the remaining production is based on polylactic acid (PLA), polyhydroxyalkanoates (PHA), bio-based polyethylene, and others. The large contribution of starch-based plastics in the market can be accounted for its several cited advantages such as high abundance, low cost, and renewability. However, starch alone is not a true thermoplastic. It must be processed in the presence of heat and mechanical treatment together with a plasticizer. This process produces thermoplastic starch (TPS). It must be combined with other materials often a filler to modify its properties. Generally, reinforcement with filler enhances the mechanical properties of starch and reduces the hydrophilic character. In bioplastic production, 50% are starch based and the remaining are cellulose and protein based. Starch based bioplastic can use corn kernels, sugar cane, newspaper, plant scraps and banana peels as sources of starch.
The Philippines is the second largest exporter of bananas after Ecuador, with some 2.6 m tonnes exported in 2012. That year, the exports from the Philippines (essentially Cavendish cultivars) made up 98% of the Asian banana trade. Two thirds of the exported volumes were shipped to Japan, China and South Korea. In 2015, the country produced nearly 9.1m tonnes of bananas on 443,270 ha, with Cavendish cultivars accounting for about 50% of national banana production, Saba (29%) and Lakatan (11%). Latundan (a Silk cultivar) and other cultivars accounted for about 11%. At the beginning of the century, as many as 90 cultivars were estimated to be grown for local consumption. The common banana, scientifically known as Musa sapientum, is a tropical fruit grown in the western hemisphere. Primarily viewed as a food source, the banana has fleshy inside portion surrounded by an outer, typically yellow, peel. The fleshy inside portion, or pulp, is edible when raw, and the peel is usually discarded. When ripe, bananas have a deep yellow rind spotted with brown, and a creamy pulp which is easily digested. Among those, banana peels are waste and is the best option in choosing of raw material. Also, banana production increased by 2.8% in 2014 to 8.88 million metric tons (MT), per Bureau of Agricultural Statistics’ (BAS) which make it an abundant source in the country. These are found to have minimum 15% starch when immature and 30-40% when ripe.
II.
STATEMENT OF THE PROBLEM
In 2014, global plastic production reached 311 million metric tons, with 59 million metric tons in Europe alone. (Global Statistics, 2014) The production process used to make plastics consumes about 10% of oil and gasoline both produced and imported by the U.S. Globally, the production of plastic accounts for 270 million tons of oil and gasoline in order to meet the demand for plastic products. (Algix.com) When a plastic’s usefulness is over, it is readily dumped into landfills and ocean environments. This gives a high impact on environmental and economic problem. Bioplastics which are biodegradable and can be made from scratch have a potential solution to the problem, environmentally and economically. Also, banana peels which is the main raw material, are considered agricultural waste that can be turned into some useful product such as bioplastic. During recent decades, there has been a continuous increase in the use of plastics and it has become the major new material replacing some traditional
ones such as paper, steel and aluminum in many applications. The main advantages of plastics are their low cost and lightweight. In addition, they are easy to formulate and require low energy for their transportation and production. The ever-growing production and use of plastics have led to a waste disposal problem because, generally, they are inherently inert to the microorganisms or the chemicals in an environment (Prinos, et al. 1998). Thus, they ca nnot degrade when exposed to the environment. Conventional garbage disposal methods such as incineration, landfill and recycling are not so attractive due to their respective limitations. Incineration needs high temperatures of more than 800o C, which makes it rarely used nowadays. Landfill has some problems of odor and the scattering of lightweight waste materials by the wind. Recycling has not yet gained widespread acceptance because of its difficulty in classifying and separating the types of used plastics. For these reasons, there has been an increased interest in the production and use of fully biodegradable polymers replacing nonbiodegradable plastics Plastics made from petroleum-based have many drawbacks. It needs a large amount of energy in the production process, besides it took years to degrade and at the same time caused serious hazards to the environment. To shift to sustainable pathways, the development of biodegradable products has increased years ago, and it continues to be the area that attracts scientists to involve with new green materials and improvement ideas. Renewable natural polymer resources such as starches were one of the most attractive materials because of its’ inherent biodegradability, ready availability and low cost (Azahari et al., 2011; Patel et al., 2011; Tang et al., 2007). Biodegradation of bioplastic can be characterized with the loss of weight, change in tensile strength, change in dimensions, change in chemical and physical properties, carbon dioxide production, bacterial activity in soil and change in molecular weight distribution (Singh & Sharma, 2008). Nowadays, starch is widely used in the fields of food technology, engineering, pharmaceutical, packaging and agriculture III.
OBJECTIVES
GENERAL : The main objective of the experiment is to extract the starch from the banana peels to produce a bioplastic sheet that conforms with the standard properties. PROPERTY STANDARD Water absorption 22.70% Tensile Strength 9.26 MPa Melting Point 120 deg Celsius Source: Green Polymer Composites Technology Properties and Applications
SPECIFIC:
IV.
To determine the amount of starch that can produce a bioplastic that can conform with the standard property. To identify the suitable parameters that will produce the highest amount of starch from banana peels through varying the different parameters such as type of reagents, concentration of reagents, mass ratio of reagents, temperature and time. To determine the amount of water to be used in washing banana peel To determine the amount of water needed to extract the most amount of starch from banana peel To determine the minimum amount of time needed to settle the maximum amount of starch from the banana starch suspension To determine the optimum time for drying the banana starch To calculate for the percent yield of each process involved.
SIGNIFICANCE OF THE STUDY
With this research, the conventional petroleum-based commercial plastics will soon be replaced by these bioplastics made from banana starch. An advantage of this is that, they will not fill up the landfills because they are biodegradable and just for months, disposed bioplastics are completely gone unlike petroleumbased plastics which takes about many centuries. This research will also be significant to the whole scientific community since it would provide added information about how to make a good, environment-friendly, inexpensive and toxic-free bioplastic from banana wastes. This research can also serve as a springboard for future researches who want to develop safe and cost effective bioplastics. This study entitled “Extraction of Starch from Banana Peels to Produce Bioplastic” is expected to be significant to the following fields: To the banana chips, banana ketchup factory owners The study utilizes banana peels as its major raw material for the production of bioplastic. This will provide the factory owners a potential market for bioplastic rather than ending up the banana peelings as waste. To the plastic industry This study promotes an environment-friendly plastic as it will provide a product that will degrade faster than the conventional plastic. Also, it promotes the
establishment of local production that will potentially be largely available in the market. To the business field Both the materials and procedure of this study could be utilized and developed by other institutions and could be a reason for a local production of bioplastic from the raw material. Moreover, this study would help create jobs for local citizens. To the Students The concepts used and the manufacturing process, as well as the literature gathered in this experiment could be used as reference for f urther studies related to the development of banana starch based bioplastic. Students could also use the process described in the experiment to observe the conversion of bana na peel to a bioplastic in a simplified laboratory set-up.
To the chemical engineering profession This study may serve as an additional reference for related and similar studies of fellow researchers. Chemical engineers could help in conducting further research and study of the process involved in the production of bioplastic. With the help of this field, scientific and economic condition in the country could be improved.
V.
SCOPE AND LIMITATIONS
This study focuses on the production of bioplastic through extraction of starch from banana fruit peelings. The main idea of the study was to determine its efficacy and to identify the parameters which can yield optimum values. This study will only focus on the production of bioplastic using starch from Banana peels. This includes the collecting of banana peels, extraction, production of the bioplastic, testing the properties, gathering and analysis of data and finally, arriving at the conclusions. It will take a week to finish the production of bioplastics since there are parts where drying is needed. The experimentation was done only up to laboratory scale. The materials used in this study are locally available. Banana Peels, the major raw material used in the study, can be collected in Dolly’s Banana Chips factory in Cavite. These banana peels are the by-product of the production of banana chips.
In the determination of suitable parameters, a number of trials were based on the existing experimental procedures of various related studies. The experimental variations involved in this study are the following:
Temperature Time Type of solvent Ratio of a material to reagent Concentration of reagents Type of catalyst Molar ratio
CHAPTER II A.
Review of Related Literature a. Raw Material
BANANA Musa sapientum which is commonly called banana is a herbaceous plant of the family Musaceae. It is known to have originated from the tropical region of Southern Asia. According to Leslie, it is now cultivated throughout the tropics. Akinyosoye reported that the plant is cultivated primarily for its fruits and to a lesser extent for the production of fibre. It is also believed to be an ornamental plant. The Musa sapientum grows up to a height of about 2-8m with leaves of about 3.5m in length. The stem which is also called pseudostem produces a single bunch of banana before dying and replaced by new pseudostem. The fruit grows in hanging cluster, with twenty fruits to a tier and 3 – 20 tiers to a bunch. The fruit is protected by its peel which is discarded as waste after the inner fleshy portion is eaten. Banana production increased by 2.8% in 2014 to 8.88 million metric tons (MT), according to the Bureau of Agricultural Statistics’ (BAS) Major Crops Bulletin, but this year’s output could suffer a setback as the prevailing mild El Niño has started to affect harvest. The average banana fruit has 32-35% skin. Banana peels generally contain 6 to 9 percent protein, 20 to 30 percent fiber and other components such as starch, sugars, lignin, tannins and minerals in varying amounts. The exact quantity of these components depends on the banana cultivar and its maturity. Green banana peels contain much less starch (about 15%) while ripe banana peels contain up to 30% free sugars.
The relationship between peel color and starch index, according to our chart, shows a reasonable positive linear correlation
The relationship between pH changes and starch index is not linear, and best fits an exponential curve (Fig. 4). During normal banana ripening, the starchiodine staining technique for assessing pulp ripe ness correlates well with color and soluble solids. Use of the technique to evaluate pulp maturity should be of value to both researchers and workers in the banana industry in evaluations when internal ripeness is more important than appearance, when color is not a usable index, or when temperature and humidity problems arise and external and internal ripening are not well-correlated
GLYCEROL (PROPANE-1,2,3-TRIOL) AS PLASTICIZER A plasticizer is a substance which when added to a material, usually a plastic, makes it flexible, resilient and easier to handle. Early examples of plasticizers include water to soften clay and oils to plasticize pitch for waterproofing ancient boats. There are more than 300 differentypes of plasticizers of which about 50100 are in commercial use. The most commonly used are phthalates and adipates. Usually, the second major component of a starch based film is the plasticizer, which is used to overcome film brittleness caused by high intermolecular forces. Plasticizing agents commonly used for thermoplastic starch production include water and glycerol (Alves et al., 2007, Famá et al., 2006, Famá et al., 2007, Jangehud and Chinnan, 1999, Mali et al., 2006 and Parra et al., 2004), polyethylene glycol (Parra et al., 2004) and other polyols, such as sorbitol, mannitol and sugars (Kechichian et al., 2010, Talja et al., 2008 and Veiga-Santos et al., 2008). Glycerol, also called glycerin, makes a very useful plasticizer. Glycerol is produced by the fermentation of sugar, or from vegetable and animal oils and fats, as a by-product in the manufacture of soaps and fatty acids. It is liquid at room temperature. Glycerol is an effective plasticizer and inexpensive, and it tends to make the resulting plastic flexible even at the very low temperatures of a freezer, as might be required for a freezer wrap. On the other hand, too much of it makes the plastic curl up in a microwave oven and turn into gum. Even more important,
glycerol tends to lose its effectiveness as a plasticizing agent over time, leading to a slow increase in brittleness (Green Plastics, 2011). Some authors consider that the glycerol, a polyalcohol found naturally in a combined form as glycerides in animal and vegetable fats and oils, is the best plasticizer for water soluble polymers (Bertuzzi et al., 2007, Jangehud and Chinnan, 1999 and Müller et al., 2008). The hydroxyl groups present in glycerol are responsible for inter and intramolecular interactions (hydrogen bonds) in polymeric chains, providing films with a more flexible structure and adjusting them to the packaging production process (Souza et al., 2010). To overcome high permeability caused by the plasticizer, other additives are used. In this area, the production of bionanocomposites has proven to be a promising option, since polymer composites are increasingly gaining importance as substitute materials due to their superior tensile properties, making them especially suited for transportation and packaging applications (Souza et al., 2012) EFFECT OF VINEGAR ON STARCH Starch dissolves better if a small amount of ions (electrically charged particles) are present in the mixture; the polymer molecules become disordered more easily, and the resulting cast films are somewhat improved. These added ions interact with both the starch and the small amounts of other polymers (lipoproteins) that are present in commercial starch. One way to add ions into the mixture is to use ammonium acetate. Ammonium acetate works very well in this respect because it forms ammonium ions and acetate ions in solution. However, ammonium acetate is not readily available. Vinegar is a practical alternative that one can use when making bioplastic. Vinegar contains acetic acid which forms hydrogen ions and acetate ions, and (importantly) it is readily available. This is why adding a little bit of vinegar is recommended specifically when making home-made bioplastic films from starch (Green Plastics, 2011) b. Process 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 bioplastic 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. In RSC’s “Making plastic from potato starch” experiment, a simple way of making plastic from potato starch is introduced and the chemical basis of the process is explored in depth. 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.
The 9th and 10th pilot experiment conducted had been successful in producing plastic, but had started to decay after only 3 days. As a result of the research done to address this issue, I found out tha t in order to improve shelf life of postharvest wild mango fruits, sodium metabisulphite can be used (Ibadan, 1991). This is why the sodium metabisulphite solution was used in this experiment.
STARCH-BASED PLASTICS Starch is considered to be a biodegradable polymer and can be used for the production of starch-based resin (Takagi, Ichihara, 2004) bioplastics. Starch when harvested is turned into a white, granular product. According to the Australian Academy of Science, “starch can be processed directly into a bioplastic, but because it is soluble in water, articles made from starch will swell and deform when exposed to moisture, limiting its use” (Packaging Greener, 2004). The starch must be transformed into an altered polymer in order to solve the issue of starch deformation. Biodegradable starches can be processed “using conventional plastic technologies such as injection molding, blow molding, film blowing, foaming, thermoforming and extrusion” (Mohanty, 2004). These starchbased plastics resemble many conventional plastics and are as, “biodegradable as pure cellulose” (Berkesch, 2005). Starch Components Starch granules are mainly composed of two macromolecular polymers of α- D-glucose, amylose and amylopectin (Banks, Greenwood, 1975). High amylose starch is defined as a starch that is composed
of at least about 40% amylose (Zallie et al. 1994) and has the ability to form a strong gel and film. Madzlan, et. al. (2012) confirms that starch high in amylose content is responsible for the production of water-soluble or biodegradable plastics Uses of Starch in the Plastic Industry Vilpoux and Averous (2003) enumerates the typical uses of starch-based plastics. Purchase bags – These were introduced in the market in 1999 and started being used in many supermarkets in Scandinavia and in the Mediterranean Coast. They were introduced in places where the collecting of organic wastes already existed and where they were accepted as biodegradable compost bags.
Consumer goods packaging – The main market is that of silk paper, but there are markets for magazines wrapping and bubble films, mainly for electronic goods.
Food packaging – Bags for fruit, vegetables, and bakery products. Starch-based plastics allow for a better breathing of the products.
Composting bags – Bags used in the selective collecting of organic waste, which will be treated to produce a compounds. Hygiene-cosmetics – Diapers, swabs, and toothpicks Funerary goods – Wraps for corpses, in compliance with the rules on the use of biodegradable materials In the granular state, it has been used as filling agent for polyolefin and as a component in synthetic polymer blends. According to Lawter and Fischer (2000), starches have also been modified by means of “grafting” with vinyl monomers (e.g., methyl acrylate), originating materials for injection in molds or extrusion. It is possible to produce starch films through the grafting of polymers, such as polyethylene (PE). Only the starch films is biodegradable and these films are practically no longer used (Lawter, Fischer, 2000). IODINE TEST When starch is mixed with iodine in water, an intensely colored starch/iodine complex is formed. Many of the details of the reaction are still unknown. But it seems that the iodine (in the form of I5- ions) gets stuck in the coils of beta amylose molecules (beta amylose is a soluble starch). The starch forces the iodine atoms into a linear arrangement in the central groove of the amylose coil. There is some transfer of charge between the starch and the iodine. That changes the way electrons are confined, and so, changes spacing of the energy levels. The
iodine/starch complex has energy level spacings that are just so for absorbing visible light- giving the complex its intense blue color. The complex is very useful for indicating redox titrations that involve iodine because the color change is very sharp. It can also be used as a general redox indicator: when there is excess oxidizing agent, the complex is blue; when there is excess reducing agent, the I5- breaks up into iodine and iodide and the color disappears. REINFORCING THE STARCH-BASED PLASTIC Starch is a granular material from vegetable origin that is composed of two natural polymers: amylopectin and amylose. These are polysaccharides with different molecular weights and structures (the latter being almost linear, while the former has a highly branched structure). Pure starch provides brittle and friable materials, but this can be improved by destructurisation, a process in which the granular structure of starch is destroyed by the combined use of shear, temperature and time to provide a homogeneous material with both amylopectin and amylose dispersed uniformly through the material (Kosior, et. al., 2006). The properties of this destructurised starch can be improved by complexing; that is, blending with other polymers (such as polycaprolactone, polyvinyl alcohol, polylactic acid and other polyesters), nanofillers, plasticisers and fibres. PROPERTIES OF STARCH BASED RESINS
STANDARD PROPERTIES OF BIOPLASTIC
BIODEGRADABILITY OF BIOPLASTIC
Unlike traditional oil based plastics, biodegradable plastics are made up of biodegradable, bio-based, or both types of materials. "To be considered biodegradable, this decomposition has to be measured by standardized tests, and take place within a specified time period, which vary according to the “disposal” method chosen. The American Society of Testing and Materials (ASTM) have created definitions on what constitutes biodegradability in various disposal environments” (i.e. Platt, 2014).
Decomposition of Bioplastic
B.
Review of Related Studies
CHAPTER III A. Experimental Study The following are the raw materials needed for the production of bioplastic from banana peels: Raw Material Banana Peel NaOH propane-1,2,3-triol 2 2 5
HCl
Procedure:
Function Source of Starch pH Adjuster Plasticizer Preservative Catalyst in hydrolysis
I.
Preparation of Raw Materials Measuring of Raw Materials In preparation for the production of bioplastic the following reagents are measured: (1) 0.5 kilogram of banana peel; (2) 200 ml 0.5% 2 2 5 ; (3) 3 ml HCl (4) 2 ml of propan-1,2,3-triol, (5) 3 ml NaOH Preparation of Banana Peels 1. The banana skin is removed using stainless steel knife. 2. The skin is washed in a running water to remove dirt and impurities. Extraction of Starch 1. A 800-ml beaker was filled with distilled water and placed over a Bunsen burner. 2. The banana peels are dipped in 0.5% 2 2 5 solution and placed in a beaker and boiled for 30 minutes. 3. After the boiling process, the beaker was removed from the Bunsen burner and the peels were decanted off the water and placed on and covered with a dry gauze pad, left to dry for 30 minutes. 4. After the peels were dried, they were placed in a clean 800 ml beaker. 5. Using a hand blender, the peels were pureed until a fluid paste was formed. Forming of Plastic 1. 25 ml of banana paste was placed in each 50 ml beaker. 2. 3 ml of HCl was added and stirred using a glass stirring rod. 3. 2 ml of propan-1,2,3-triol was added to each bea ker. The mixture was stirred once more. 4. 3 ml NaOH is added and stirred using a glass rod. 5. The mixture was poured into a petri dish and put in the oven at 130 degrees Celsius. It was baked for half an hour.
II.
III.
