REVIEW OF RELATED LITERATURE
This investigatory project aims to make use of rambutan peeling extracts that is high in phenolic compounds such as tannin and saponin that exhibits antioxidant activity and antibacterial activity against pathogenic bacteria. Although the seeds contain such compounds the peeling exhibit greater amount of the said compounds. Rambutan is a very popular fruit cultivated in the Philippines and it is eaten in large amounts. The rambutans rind is quickly discarded and thrown out after it is cut open and peeled off. The researchers will be maximizing the use of rambutan peelings through this project before they are disposed of. Not only will the researchers maximize the use of the peelings, they would be finding ways to help the environment since they would be making use of the peelings. Their target is to find a suitable product that would be used as a daily component in cleaning or disinfecting objects and such, the purpose of making it such is so that it would be able to prevent the spreading of bacteria which is commonly transmitted through contact with an infected object.
The main ingredient of this experiment is Nephelium lappaceum L. or more commonly known as Rambutan. This tropical fruit from the Sapindaceae family is native to most of the countries in Southeast Asia. The fruit varies in appearance but it is most commonly known for its round or oblong shape, red color (indicating ripeness) and soft spines or pliable thorns. The Rambutan is abundant in tropical and humid regions with well-distributed rainfall. Studies show that the rambutan fruit contains antioxidant and antibacterial properties. Peel extracts from the fruit have higher antioxidant activity than in those of the seeds. Antioxidants are molecules that protect cells from the damage of free radicals by counteracting its effect. Free radicals are highly reactive groups of atoms with an unusual number of electrons. A reaction with cellular components is dangerous and the antioxidants prevent this from happening.
The peel extracts also exhibit antibacterial activity. In the article by Thitilertdecha, Teerawutgulrag, Kilburn and Rakariyatham entitled Identification of Major Phenolic Compounds from Nephelium lappaceum L. and Their Antioxidant Activities a test on five gram negative bacteria (bacteria that lose the crystal violet stain [and take the color of the red counterstain] in Gram’s method of staining) and three gram positive bacteria (bacteria that turn a dark-blue color in Gram’s method of staining) was conducted to see if they were affected by the antibacterial activity found in the peel extracts. Vibrio cholerae, Enterococcus faecalis, Staphylococcus aureusa, Staphylococcus epidermidis and Pseudomonas aeruginosa, these pathogenic bacteria were found to have positive results. Pathogenic bacteria are disease causing.
The research of Schoenstadt in 2008 elaborates on Vibrio cholerae as the cause of cholera; an acute, diarrheal illness that can result in severe dehydration and even death within a matter of hours.Because of their option to either operate with oxygen or without oxygen, they are facultatively anaerobic. Vibrio cholerae being the cause of cholera has created a worldwide pandemic that started four decades ago. About 80% of all the cases that have been reported globally came from Africa while industrialized nations like the United States have no cases at all or rarely have a year.
Enterococcus faecalis is present shortly after birth in intestinal tracts of people and are unharmful at first. When they are genetically mutated they become pathogenic and can cause serious infections and clinical infections in humans. Like the Vibrio cholerae bacteria, it is also facultatively anaerobic. This nosocomial pathogenic bacterium, bacteria originated from hospitals, is feared because of its resistance to antibiotics making it challenging and difficult to treat. This pathogenic bacterium is part of the skin flora and is located in the area of the nose and on skin. The Staphylococcus aureusa bacteria can cause a range of illnesses from minor skin infections to deadly diseases. It is the most common bacteria that causes staph infections such as pimples, boils, impetigo, cellulitis folliculitis, carbuncles, scalded skin syndrome and abscesses. Examples of the more serious sicknesses are pneumonia,meningitis, osteomyelitis, endocarditis, toxic shock syndrome (TSS), bacteremia and septicemia. Like the other listed pathogenic bacteria, Staphylococcus epidermidis is also nosocomial and facultatively anaerobic. It affects the skin and is non hemolytic, hemolytic meaning relating to the rupture or destruction of red blood cells. It infects on people with weak immune systems.
The infections often start out as skin wounds caused by flexible tubes called catheters. According to Bukhari, “Catheter infections along with catheter-induced UTIs lead to serious inflammation and pus secretion. In these instances, urination is extremely painful.” Other diseases of Staphylococcus epidermidis are septicaemia and endocarditis. The study of Qarah, Cunha and Dua in 2009 stated that pseudomonal pathogens evidently inhabit nature like soil, water and surfaces of plants and animals, including us humans. Pseudomonas aeruginosa is widely infectious especially to those with problems involving their host defense mechanisms. It frequently causes nosocomial infections such as pneumonia, urinary tract infections (UTIs), and bacteremia. This pathogenic bacteria’s infections are complicated and can be life threatening.
How Bacteria is Transmitted or Spread
In an article entitled How does Bacteria Spread by Sueanne Dolentz there are different ways Bacteria is transmitted one of the most common ways is through contact and poor hygiene. It is spread through contact because once a person touches a bacteria-laden object such as doorknob and or by making hand contact with a person the bacteria is transmitted to the person. It is spread through poor hygiene when a person does not properly wash their hands and or clean themselves after using objects and things that are dirty, and when they don’t wash their hands regularly they could spread the bacteria from one person to person, when they touch objects, when they make contact, or when they touch their face which is done frequently by people. Thus with the product developed by the researchers, it would be able to prevent spreading due to chemical compounds found in the product which affects the bacteria.
Using the method of solid-liquid extraction, the researchers will remove the soluble components that exhibit antibacterial activity from the solid rambutan rinds with the use of a solvent. In the study of Antioxidant and antibacterial activities of Nephelium lappaceum L. extracts by Thitilertdecha, Teerawutgulrag and Rakariyatham (2007), they used three solvents; ether, methanol and water. Methanol exhibited the highest yield in peel extracts. In line of this study, the researchers will be making use of methanol as their extraction solvent. Before submerging the rambutan in the methanol solvent they will moderately pulverise the rambutan rinds for a faster and more complete extraction. They will leave the extraction material (rambutan rinds) in the solvent for a very long period of time. To determine whether the extract already contains antibacterial properties the researchers will go to a laboratory and have it tested using the disc diffusion method.
Disc Diffusion Method
The disc diffusion method is one of the most commonly used methods of antimicrobial susceptibility testing. By the definition of Lab Tests Online, susceptibility testing methods are used to determine the likelihood and effectiveness of an antimicrobial agent on stopping the growth of bacteria. On an agar plate (a petri dish containing a growth medium which is usually a gelatinous material from certain marine algae called agar plus nutrients) swabbed with bacteria, small filter paper disks that were permeated with the methanolic extraction of the rambutan rinds with antibacterial activity will be positioned on the plate. The plate will be incubated overnight. The size of the spots of the situated bacteria will be observed. Large spots indicate the bacteria’s susceptibility to the antibacterial activity of the methanolic peel extracts of the rambutan while small spots indicate the resistance of the bacteria from the antibacterial activity.
This investigatory project would make use of the rambutan rinds which is usually discarded. Unlike other researches which only have found what chemical compounds are found in the peelings. The researchers would make use the compounds found in the rinds to develop a suitable product that would be used as an antibacterial or disinfectant for objects. This project is unique not only because it hasn’t been done yet but because of the fact that it makes use of an exotic fruit that is commonly cultivated in South East Asia. In conclusion it is wished that rambutan peelings would make as great alternative material or chemical compound for a disinfectant or antibacterial solution. Not only that but to develop a product that is eco-friendly and affordable to all but to prevent the spread of bacteria.