A healing rose
A rose by any other name will be as sweet, wrote Shakespeare. Ever sensuous and sweet, the splendour of rose is everywhere, enchanting romance and love. But other than romancing, a rose can also speak serious matters. There is medicine in a rose.ROSES have been grown as garden plants and cut flowers for decor, fragrance and flavouring. Now there is no less than 7,500 varieties of rose. Not only scenting a garden and beautifying homes, history also shows roses have been used in medicine, food, perfume, and health. They have essential oils for perfumes widely used in cosmetic. The scent of a rose can be in many forms - rose water, rose petals, rose buds, and rose oil.
Knowing there are many uses of roses, researchers Roziana Mohamed Hanaphi and Dalina Samsudin worked to find another use of a rose - an antibacterial agent. Rose extracts were prepared from fresh roses and rose residue using solvents of different polarity.
Influenced by how our forebears used plants to heal diseases, Roziana and Dalina studied that botanical extracts have long been used to treat disease. Plants are a rich source of valuable compounds and have been a source of primary health care in many developing countries. These compounds are the active principle of many drugs. Thus screening of such plant extracts for antimicrobial activity has always been of great interest to scientists to look for new sources for food additives, cosmetics and drugs.
Thus likewise, Roziana and Dalina saw that roses have potential against microbial activities. They attempted to prove that the ethnobotanical use of rose petals can be a cure for diarrhea and enlarged tonsils, commonly caused by E.coli. In their experiment, an extraction process using several solvents was conducted, testing the extracts for antibacterial activity on Escherichia coli - the gram negative bacteria, through Kirby-Bauer disc diffusion method.
The petal tissues of flowers may possess antibacterial activity as their natural protection system for reproduction and further perpetuation through seed formation. So some rose varieties have been studied for different activity potential at genotypic level. They were found to be active against the gram-positive and gram-negative bacteria with differences in activity profiles.
Usually, the different polarity compounds are extracted from roses but in this study, it was extracted from the roses residue. Extracted roses usually contain linalool, phenylethyl alcohol, citronelol, nerol and geraniol. While the main compounds of rose extracted by solvent extraction are isopropyl myristate, rhondinol, 1-nonadecene and heneicosane. These compounds can be detected by gas chromatography with a spectrometry apparatus and generally, they have different polarity where they will be separated into similar groups of polarity solvent.
As the objective of the solvent extraction method is to separate the organic mixture into a similar groups of compounds, theoretically, the extracted polar compound has the tendency to be with the polar solvent. Hence the non polar compound will be rather chosen to be the non polar solvent.
To find antibacterial values, Roziana and Dalina employed the Kirby Bauer disk diffusion susceptibility test. It was to determine the susceptibility or resistance of pathogenic aerobic and facultative anaerobic bacteria to various antimicrobial compounds. They screened the extracts for antibacterial activity where a paper disc was soaked with the rose extracts then laid on the top of an inoculated agar plate.
During incubation, each chemotherapeutic agent diffuses out from the disc in all directions. Agents with lower molecular weights diffuse faster than those with higher molecular weights. Clear areas, called zones of inhibition, appear on the agar around discs where the agents inhibit the microorganism. An agent of large molecular size might be a powerful inhibitor even though it might diffuse only a small distance and produce a small zone of inhibition.
Good news folks, Roziana and Dalina found that the fresh rose ethyl acetate extract showed the most promising result tfrom the other four extracts. It showed a 39 mm zone of inhibition on Mueller Hinton agar, the largest diameter zone compared to the other extracts, indicating that the Gram-negative bacteria of E.coli were highly susceptible to the extract. This means the rose extract was potential to kill or retard the growth of E.coli. They concluded that the intermediate polar compounds in roses either fresh or residues, are giving great potential as antibacterial agent in order to inhibit the E.coli.
A rose not just romances, it heals.
Information contacts:
Roziana Mohamed Hanaphi
Dalina Samsudin
Faculty of Applied Sciences
UiTM Perlis
roziana@perlis.uitm.edu.my
dalina@perlis.uitm.edu.my
Steaming hot meehun soup
IT is great to eat steaming hot noodles, sipping hot meehun soup and drinking teh tarik at stalls and mamak shops. Fast and simple, the hot noodle soup is served in plastic bowls and eaten with plastic forks and spoons. Then we buy hot noodles for meals at home packed in polystyrene containers. But Hazlina Husin and her professor, Ku Halim Ku Hamid, saw danger in steaming meehun soup and noodles in these containers.
Plastic products are used by all every day. Convenient, cheap and handy, but putting hot food in plastic containers is dangerous said scientists. They explain that there are a few types of plastic food containers, having certain properties developed during their manufacturing, but even though plastic food containers are made to follow their industrial specifications, these requirements are sometimes brushed off by manufacturers and consumers.
The lack of awareness by users about plastics organic chemistry poses more danger. Many do not know that plastic products have constraints that limit their uses, such as limited hardness, density, ability to resist heat, oxidation, organic solvents and ionizing radiation. The possibility of chemical compounds, leachate, diffusing into the food in the plastic food containers is high. This leachate is toxic and carcinogenic.
Leachate is a term used in the environment for effluent produced by a new or used material(s). Leachate from plastics food containers dumped in dumpsites will also diffuse into the surroundings and affect soil and rivers.
Worse, food-safety problems tend to rise when plastics are used for a purpose other than what they are designed for, such as polystyrene and microwave-safe food containers used to pack hot foods. Due to organic chemistry limitation, chemical compounds in polystyrene could diffuse into the food or drink in it. It is studied that leachate diffusion will be worse if the food is hot and placed longer in them.
Hazlina and her professor evaluated the possibility of a leachate flow from polystyrene and microwave-safe food containers to food. They conducted an experiment to study this diffusion using two types of common food containers, polystyrene and microwave-safe, which were cut into small pieces. A stainless steel variable-speed heating container was used and our favourite chicken soup and meehun soup, were the contact medium. The stainless container then was filled with 200 mL of soup. Gradually, the cut plastic food container was added into it. The temperature of the container was set at 30, 50, 60, 80 and 90oC per testing batch. Food samples were then taken from the sampling container after 15 minutes. After that, the test was continued for variable storage time: 10, 15, 20, 25 and 30 minutes per testing batch, then analyzed by GCMS.
The GCMS analysis identified six extractives: Dodecamethylcyclohexasiloxane, tetradecamethyl cycloheptasiloxane,1,2-benzenedicarboxylic acid diethyl ester, hexadecanoic acid methyl ester, 1,2-benzenedicarboxylic acid dibutyl ester and pctadecenoic acid methyl ester. These extractives were the components of the leachate that diffused from the cut food containers.
Hazlina found that the highest peak identified in the extractions was the 1,2-benzenedicarboxylic acid diethyl ester, also known as phthalates esters. Phthalates esters have attracted great public attention because of their carcinogenic and estrogenic properties, which are unfortunately used as one of the plasticizers in plastics products.
Another series of test on ionization count of each chemical compound to evaluate the possibility of leachate diffusing into food was conducted. She found that more leachate was found in the food samples when the polystyrene food container was used. Leachate diffused from a polystyrene food container at a temperature of more than 30oC. Microwave-safe- food container was found to be safer when it was shown that the leachate diffused only at a temperature higher than 50oC. Likewise, it showed that the higher the temperature of food, the more the leachate diffused. She found this trend in both types of food containers.
Polystyrene is made from one of the most important and global industrial chemicals commonly used for food-contact packaging materials. Unfortunately, human exposure to styrene happens by the diffusion of these food packaging materials into food. It is estimated that human daily styrene exposure is in the range of 0.2 to 1.2 µg/person.
Leaches of styrene, an endocrine disruptor mimicking the female hormone estrogen, has potential to cause reproductive and developmental problems. Styrene diffuses significantly from the polystyrene containers into food when the foods are heated in them. In contrast, microwave-safe containers have little leaches and found to be safer even at high temperatures. These containers are made of polypropylene which are considered ‘safer’.
Their analysis also showed that the diffusion of leachate into the chicken soup and meehun soup in the experiment was also related to how long the food was placed in it. In this study, chicken soup was used as the contact medium, which was stored at 50oC in a polystyrene. Within 5 minutes, the TIC of 1,2-benzenedicarboxylic acid diethyl ester increased from 0 to about 500. Hazlina commented that the diffusion rate for the leachate here was high at this temperature. It was also found that the leachate diffused after 10 minutes of food storage time. So, if hot soup is placed in polystyrene for more than 10 minutes, we can say that there is a high possibility that leachate will diffuse into the soup.
Here Hazlina and her professor managed to show that the public should be aware of the danger of eating or putting hot foods in this type of containers. They also suggested that a comprehensive study on the stability of chemical bonding in the food containers and leachate flow into food be done on biodegradable plastic food containers. There is also a need for a database of leachate monitoring to measure the safety level of leachate-content in food.
Or after all it is good to eat our steaming meehun soup from Tok Mak‘s old bowls.
Information contacts:
Hazlina Husin
Ku Halim Ku Hamid
Faculty of Chemical Engineering
UiTM Shah Alam
hazlina858@salam.uitm.edu.my
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