Noor, N.A.M., & Hua, A.K. (2016). Cooking Oil Management in Cafeteria Operators. German: LAP LAMBERT Academic Publishing
Page Cover
Imprint
Abstract
Contents
Chapter 1
Chapter 2
Chapter 3
Chapter 4
References
Page Cover
Imprint
Abstract
A preliminary survey of used cooking oil management among cafeterias in University of Malaya, Kuala Lumpur was conducted. The objective of this survey to know the attitude of the respondents towards the awareness in proper used cooking oil management. Seven questions were given randomly to the 20 cafeterias throughout in the University of Malaya, which include café that are located in students’ residential area, faculties and students lounge areas. Data were collected through site visit and face-to-face interview. 90% of the food business operators run Malay food business while 10% run other food business. It was found that 45% of the 20 cafeterias consumed 21-30L of oil per day. Besides that, the result showed that 75% of respondents used the cooking oil 2-3 times before discarded it. The highest percentage of method disposal of used cooking oil by respondents was 50% by poured down used cooking oil directly into sink or drainage. Meanwhile, 35% thrown are the used of cooking oil it which consider as normal waste. However, 15% of them that have awareness sell their waste cooking oil to some recycling or waste treatment companies. 50% of cafeteria operators were not acknowledged that repeated usage of cooking oil is malicious. Only 20% of cafeteria operators know the effects of repeated usage of cooking oil. As a conclusion, the result from survey showed that there is a severes lack of knowledge and awareness about proper used cooking oil management among the cafeteria operators in University of Malaya.
Keywords: health, environment, safety, used cooking oil
Contents
Contents
Chapter 1
Introduction
Objective
Research background
Methodology
Chapter 2
Literature Review
Chapter 3
Results and Discussion
Chapter 4
Conclusion
Recommendation
Acknowledgement
References
Appendix
Chapter 1
Introduction
In a global world, cooking oil is used for the preparation of food. Cooking oil is a plant, animal, synthetic fat used in frying, baking and other types of cooking. Scientific definition of cooking oil is glycerol esters of fatty acids. Common types of cooking oil use by Malaysian are palm oil, peanut oil, corn oil and sunflower oil. They are used as a heat-transfer medium in frying to generate nicely cooked foods. Cooking oil is typically liquid, although some oils that contain saturated fat such as coconut oil, palm oil and palm kernel oil are solid at room temperature.
Malaysia is among top three exporter of palm oil in the world. About 40% of palm oil mostly made into cooking oil, margarine, specialty fats and oleochemicals. Major of cooking oil made from palm oil. Meanwhile, used cooking oil term refers to cooking oil that is no longer used in food production. The main producers of used cooking oil are the restaurants, food stalls, night market also cafeteria. The disposal of cooking oil becomes a huge problem because of fried food such as fried chicken, French fries and burgers can produce as much as 15 litres of used cooking oil per day not including restaurants that provide Malay food. There are more than hundreds of restaurants in Malaysia and larger volume of used cooking oil is generated per day.
Production and consumption of cooking oil causes the amount of waste cooking oil generated also increases. Cooking oil allocation in Malaysia was reported 7000 tonnes a month in 2010 ( Akademi Science Government, 2012 ).
This figure showed the allocation of cooking oil vs consumption of cooking oil on 2010. We can see that the highest consumption of cooking oil on January and also on Ramadhan month with more than 73, 000 0000 tonnes. This is because although it fasting month but many restaurant, hotel, night market or “Bazar Ramadhan” will open on evening that provide various of food. This is a major factor why the graph of consumption cooking oil drastically increasing.
It not includes deep frying meat-based products such as Kentucky Fried Chicken, McDonald, Burger King, “keropok lekor”, fish cakes and sausages. Majority of Malaysian people especially kids and teenagers like deep fried foods due to their taste, smell and texture. Frying is also one of the easiest and cheapest ways of cooking.
Even though a little amount of potential toxic products such as polar compounds or polymers are produced during frying, fried foods are considered safe. However, it becomes toxic for human consumption if the frying oil is used repeatedly. (Artman, 1969)
It was reported that waste cooking oil is widely produced all over the world (Kulkarni and Dalai, 2005). Improper waste management of cooking oil leads to discharge of waste cooking oil to environment and this will effect environment and danger to human health. The increasing production of waste cooking oil from household or food industrial source is growing problem in Malaysia. The waste cooking oil is regularly poured down directly to sink or drain resulting in problems for wastewater treatment plants. Fat, oil and grease cause major problems to drain and sewers. When they are discarded of down kitchen sinks or drains they cause blockage. Meanwhile they cause pollution in streams and rivers when they enter rainwater pipes. Oils and grease may cause the clogging of the pipes because they stick to the inner walls and reduce the diameter of the sewer pipes. Sewage spills will occur when the layer is thicker. Then worst condition is it will disrupts normal operations if the oil reaches the wastewater treatment plants and both maintenance costs and the rates to be paid for the purification of the water will increase (Payri et al., 2004).
The eating habits of the nation are changing; people are eating out much frequently than they did in the past. Majority of the preferred to eat outside home and it cause the number of food business is increasing. One more major problem of Malaysian people either in household or food business sector, repeatedly usage of the same frying oil becoming a common practice which is mainly intended for cost saving or budget constraints. Few related articles to this hot topic have been published previously also mentioning the seriousness of this practice to the human health.
According to literature review, the oil is discarded only when the oil becomes foamy, produce bad smell or when the color of the repeatedly used oil turns dark (Azman et al, 2012). In addition, the consumption of repeated usage cooking oil is unhealthy and mallicious to consumers because cooking oil is heated to a temperature of 170-220 degrees Celsius during frying. Upon heating, cooking oil may undergo chemical reactions, hydrolysis, oxidation and polymerisation. Degradation products such as free fatty acids, hydroperoxides and polymerised triglycerides may be formed. Besides, the viscosity of the cooking oil will increase; its colour will go darker and rancidity will also develop, giving rise to unpleasant flavour as a result of oxidation. Recent study conducted showed that consumption of repeatedly heated cooking oil resulted increased blood pressure and necrosis of cardiac tissues in experimental rats. The increase in blood pressure due to consumption of repeatedly heated cooking oil might be due to quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure (A. Azman, S. Shahrul and et al, 2011).
Using of repeatedly used oil can cause adverse effect to the human health. However, this practice becomes common among Malaysian without their aware that this type of oil can harm the human health (Kamisah et al, 2012). Many local communities are not aware the issues due to lack of information and knowledge of waste cooking oil management especially for food outlet business operators, a step must be taken to overcome it. However, it has can be recycled and has potential as value-added products such as biodiesel, lubricants, biopolymers or soap.
The survey process also proves that the hazardous effects of waste cooking oil to human health and environment. The Malaysian Food Act and Regulations, September 2005 has no provision and regulatory for cooking oil quality. Food safety, which includes aspects of food handling and food processing, are addressed by specific food safety programme such as Good Manufacturing Product (GMP). Member countries look toward Codex Alimentarius to set food standards or guidelines in global country. However, Codex has not yet developed guidelines for fried oil quality. (Malaysian Food Act and Regulations, 2005)
Fortunately, there are great potential in the recycling of used cooking oil, which attract interest in the collection process for the production of biodiesel. Used cooking oil into biodiesel it is possible by recycling to generate income source and reduce environmental pollution and fossil fuel dependence. However, everything has a risk. The biggest risk of recycling this used cooking oil is its collection, mainly due to the high costs. For a company or a local administrative unit that wishes to make the collection is difficult to do because they need through standard waste collection methods (Wang et al, 2006).
Objectives
-To determine the level of awareness of food cafeterias operators towards proper waste cooking oil management.
-To investigate the practice of cafeterias operators regarding the usage of repeatedly cooking oil
-To know level of knowledge of repeated usage of cooking oil towards human health among food business operators.
-To investigate the effect of repeatedly usage of cooking oil towards human health
-To study the potential of used cooking oil recycling towards biodiesel production
Research background
Methodology
Study design
The survey were distributed to 20 cafeterias throughout in the University of Malaya, Kuala Lumpur, Malaysia which include café that are located in student’s residential areas such as 4th college, 5th college, 7th college, 11th college and 12th college. Some of residential college doesn’t have their own cafeteria such as 3rd College and 6th college. The survey also conducted in faculty of Science, Islamic Studies Academy and students lounge areas which called Perdana Siswa Complex to survey the attitude of the respondents towards the awareness in used cooking oil management. Personal information like race, type of food business in each cafeteria, gender of participants were recorded as supplementary information. The main questions such as volume of waste cooking oil consumed per day, the frequencies of the waste cooking oil being used repeatedly, the method disposal of used cooking oil by respondents and the level of knowledge regarding repeated usage of cooking oil towards human health were asked to all respondents. Survey was done by site visit and by face-to-face interview. The data were collected, evaluated, analyzed and depicted in the form of pie charts.
Chapter 2
Literature Review
Eur J Lipid Sci Techno 2007;109: 289 (Basiron Y, 2007)
Palm Oil production through sustainable plantations.
Majority of Malaysian people prefer to use palm oil for frying. This is as expected since Malaysia is currently among world’s top producer and exporter of palm oil. Furthermore, palm oil is cheaper and widely available in Malaysia. Other types of cooking oil such as soy and corn oil are not really preferred choice probably due to their price that more expensive compare palm oil. Meanwhile, soy, corn and sunflower oils are more preferred choices in Costa Rica , a developing country in Latin America even though palm oil costs less.
However, palm oil would be better choice if the practice of using oil repeatedly for frying is necessary due to budget constraints. This is because palm oil able to withstand being heated repeatedly better than soy oil. Previous studies have suggested that the unique composition of palm oil allows it to withstand heat better than soy oil. Firstly, palm oil rich in monounsaturated fatty acids ( MUFA) but has low level of polyunsaturated fatty acids( PUFA) compared to soy oil. PUFA is more easily oxidized compared to MUFA. Repeated heating of vegetable oil high in PUFA results in formation of toxic compounds that increased the risk of hypertension, whereas oil that are rich in MUFA such as palm oil and olive oil can better withstand oxidation and formed less degradation products when they are heated. (Serbinova E, 1991)
Secondly, palm oil is rich in its ability to withstand thermal oxidative changes. Therefore, repeated heating of frying oils might destroy the vitamin E content and exposes the fatty acids to oxidation. The vitamin E content of palm oil mainly consists of tocotrienols, while the main vitamin E in soy oil is tocopherols. Tocotrienols have better antioxidant capacity than tocopherols. And this contributes to the better resistance to oxidative changes due to repeated heating of palm oil. (Kagan, 1991)
Medical Journal Malaysia Vol 67 No 1 February 2012
( A.Azman, S. Mohd Shahrul, S. X.Chan, A.P Noorhazliza, 2011 )
Level of Knowledge, Attitude and Practice of Night Market Food Outlet Operators in Kuala Lumpur Regarding the Usage of Repeatedly Heated Cooking Oil.
Consumption of repeatedly heated oil can be malicious to human health. It is a common practice in the household or in food business sector especially to reuse same frying oil more than 2 times because of budget constraints. Deep frying is a frying process where the food is completely immersed in the frying oil in the presence of air and moisture at temperatures of between 160-190ºC. Chemical reactions such as oxidation, hydrolysis and thermal polymerization occur when cooking oil is heated during the deep frying process.
The quality of oil deteriorates with increased length of frying time due to the accelerated formation of oxidized and polymerized lipid in the frying medium. Frequently used heated cooking oil can cause changes in physical appearances of the oil such as increased viscocity, darkening in colour, increased foaming and decrease in smoke point. The rate of formation of cooking oil decomposition products depends on the type of food being fried, the type of oil used and the design of the fryer. ( Stevenson, 1984 ).
Consumption of frequently used cooking oil may increase the risk of developing atherosclerosis. Lipid peroxidation products induce oxidative stress in endothelial dysfunction that could lead to the formation of atherosclerosis. Morever, thermally oxidized lipids enhance peroxidation of membrane macromolecules, contributing to their mutagenicity and genotoxicity which could potentially lead to carcinogenesis.
(Department of pharmacology, Faculty of Medicine, Universiti KebangsaMalaysia,2011)
A recent study conducted in their department showed that consumption of soy oil that has been reused frequently might cause an increase in lipid peroxidation and LDL in ovariectomized female rats ( which stimulates a post- menopausal state with oestrogen deficiency n humans). Another recent study conducted in laboratory resulted in increased blood pressure and necrosis of cardiac tissues in experimental rats. The increase in blood pressure due to consumption of repeatedly heated cooking oil might be due to quantitative changes in endothelium dependent and independent factors including enzymes directly involved in the regulation of blood pressure (Leong, 2010)
Aust N.Z.J Public Health 2002 ; 26(2): 101
( Morley, John J, Swinburn BA, Metcalf PA, 2002 )
Quality of frying fat and deep frying practices in New Zealand fast food outlets
A study conducted in New Zealand showed that only 8% of independent food outlet operators had formal training in deep frying practices compared with 93% of franchise food operators. That study also revealed that 65% of food outlet operators surveyed changed the oil used for frying at least once a week, however, many of them relied on late signs of oil degradation in their decision to replace an old batch of oil with a new one.
Department of Production Engineering, Federal University of Santa Maria (UFSM) Av. Roraima 1000 - 97105-900, Santa Maria - RS – Brazil ( Carlo Alessandro, 2005 )
Used Fried Oil under the Environmental Perspective
The increasing production of waste cooking oil from household and food business operators is lead problem in Brazil and everywhere the world. This residue is regularly directly poured down the sink or drain, resulting in problems for wastewater treatment plants and energy loss, Furthermore, it might integrated into the food chain through animal feeding, thus becoming a potential cause of human health problems (Costa Neto et al, 2000).
Nowadays, most of the used cooking oil is poured into the sewer system of the cities. This contributes to the pollution of rivers, lakes, sea and underground water, which is very harmful for environment and human health (Hamasaki et al, 2001). Morever, oils and and grease may cause the clogging of pipes because they stick to inner walls and reduce the effective diameter of the sewer pipes. If this layer becomes thicker, it may cause sewage spills. On the other hand, if oil reaches the wastewater treatment, it disrupts normal operations and increases both maintainance costs and the rates to be paid for the purification of the water ( Payri et al, 2004).
Mostly household preferred to place the used cooking oils in a plastic bottle, closed and place them in the garbage. The garbage is separated and the bottles will be opened and leaked in an appropriated place instead of being poured in the sewers, This is an alternative practices because it prevent unnecessary expenses with treatment in the sewer stations.
Only a small amount of the used cooking oil is properly collected and recycled, especially in rural areas (Groschen, 2002). In this situation, biodiesel manufacturing may be an alternative option for reusing waste cooking oil.
International Journal of Biomolecules and Biomedicine ( Manoharan Sivananthan et all, 2013)
Factors that can affect the quality of cooking oil during heating ( Jaarin et al, 2011)
According to a group of researchers they stated that several factors can be included like ventilation, temperature and heating duration during the process of frying, oil type, the oil saturation ratio, and the presence of a catalyst/antioxidant. It will lead to changes in fatty acid where it convert from the cis isomer to the trans isomer when oil is repeatedly use at high temperature (> 180°C. From a research conducted by these researchers found that chronic consumption of heated palm and soy oils for the duration of 24 weeks lead to significant increase in blood pressure. This proved that usage of repeatedly heated cooking oil can lead to human health problem. Free radicals are generated and vitamins and antioxidants levels are reduced when this oil is heated repeatedly which lead to oxidative stress ( Jaarin et al.,2011)
Vegetable oils that used for cooking contain excellent source of vitamin E at the concentration of between 15 and 49 mg a-tocopherol equivalents/100g. The process of oxidation of unsaturated of unsaturated fatty acids lead to the lost of vitamin E during heating. The food is absorbing the frying oil. The amount of the oil absorbed by the food based on the quality of the oil used for cooking process and this affect the amount of vitamin E’s net intake. (Ghidurus et al.,2010)
Total polar Compounds and Acid Values of Repeatedly Used Frying Oils Measured by Standard and Rapid Methods. (Wei-An Chen et al, 2013)
Deep frying is commonly utilized for food preparations such as frozen per-fried foods, snack foods, and fast foods. Fried foods are more popular today in many country especially among kids and teenagers. We can be observed from the rapidly increasing number of fast foods restaurants and vendors in the last few decades. Deep frying of foods at high temperature creates the special flavor, golden brown colour and crispy texture. It is fact that frying causes oil to undergo hydrolysis, oxidation and thermal reaction and consequently numerous byproducts such as fatty acids, alcohols, cyclic compounds, dimmers and polymers can be produced. Some products of decomposition in used oil have been identified to have adverse effects on human health, as they may have a higher chance of absorption into the fried foods. Therefore, it is important to understand and know the factors affecting the deterioration of frying oil and to monitor the quantity of products of decomposition for ensuring the quality of fried foods.
The mechanism of thermal degradation of frying oil is complicated. Variables involved in the process include frying condition, replenishment of fresh oil, original ol quality, food materials, and fryer type. Cooking oil with more saturated fatty acids such as palm oil are usually more stable for frying. On the other hand, soybean oil with more unsaturated fatty acids is less stable, and decomposes easily at high frying temperature. In Taiwan, soybean oil is one of the most commonly used cooking oils at household and is also used by many small vendors for frying. Palm oil is mostly used commercially to prepare fried potato foods. Among frying oils, those with high oleic acid content such as sunflower oil and palm olein have better healt profile and heat stability. Moisture in foods induces and accelerates oxidation with the hydrolytic compounds. Food with high water content like potato and foods with breading or battering materials cause faster hydrolysis of frying oil.
The content of total polar compound and acid value are the most predominant indicators for oil quality and are widely used in many international regulations. For public health concerns, the content of total polar compounds in frying oil are regulated at no more than 25% and 2.0 mg KOH/g, respectively in Taiwan. Determination of total polar compounds in frying oil provides a more robust measurement on the extent of deterioration in most situations due to its higher accuracy and reproducibility (Fritch, 1981). The contents of free fatty acid (FFA) and total polar compounds were commonly used for initial oil quality assurance and after-use frying oil quality assessment respectively. However, the standard analytical procedure for oil quality evaluation needs to be done in a laboratory with proper equipment by skilled technicians. It is not suitable for a small restaurant, cafeteria or small food business sector (Bansal, 2010)
(Food and Environmental Hygiene Department, 2011)
How can the hazards of used cooking oil can be controlled
In food business sectors, this hazard can be controlled by implement of Good Manufacturing Practice (GMP). The purpose of GMP are to optimize the life of cooking oil for maintain food acceptability and wholesomeness, to avoid extensive oxidative decomposition and formation of polymeric compounds.
The characteristic of Good Manufacturing Practices (GMP) includes the choosing cooking oil of good quality and consistent stability, using the properly equipment, selecting the lowest possible frying temperature, filtering cooking oil frequently to remove food particle, cleansing equipment frequently and must replacing cooking oil as needed to maintain quality. This GMP practices is important especially for food business operators. Its their responsibilities on the general health of the Malaysian population.
Moreover, the Food and Environmental Hygiene Department (FEHD) monitors the quality of cooking oil through its food surveillance programme. The samples of cooking oil for analysis will take by health Inspectors to ensure they are suitable for cooking and safe for human consumption. The public Health and Municipal Service Ordinance (Cap 132) stipulates that sale of food not fit for human consumption is an offence. Offenders shall be liable to a maximum fine $50.000 and imprisonment of six months.
Good practice of frying (Kurt, 2005)
The author of this journal said that the cooking of food was one of the first steps to create new flavor and textures to make food not only nutritious but also enjoyable. Frying involves close contact between the oil used and the raw food being cooked. Oil is absorbed by the food and contributes significantly to its flavor and nutritional properties, and becomes a major component of the final product consumed. The author also recommended some data about different temperatures are required for various foods.
At frying temperature, complex chemical changes take place. Initially, these changes create desirable flavor cause the gelatinization of starch, the denaturation of proteins, and some changes in the oil. Finally, the food becomes cooked. However, if the temperature or cooking time is not controlled, too much “chemistry” occurs and the food is spoilt. So the author focused on three main methods of frying such as shallow pan frying, deep frying in batch fryers, and deep frying in continuous fryers.
Shallow Pan Frying
Shallow pan frying suitable for some foods such as fried egg, it is easy to see when it sufficiently cooked. At the end of cooking, most of the oil would be absorbed into the food, the residue is discarded and poured into bottle to sell and the pan is washed.
Continuous fryers
The production of fried snack food and convenience food on a manufacturing large scale requires continuous fryers. The size of fryers is chosen depending on the production volume and the cooking time required. Special design features are incorporated for specific product: for example, a turnover system for doughnuts and a submerged belt to hold down products and ensure complete cooking.
The author also does researched from university canteens regarding the proper management of good practice frying oil. After training of staff and implementation of an HACCP system, a second survey found no results higher than 23% total polar materials. The training was based on the good personal hygiene, adequately done of frying, oil must be filtered, the rate of frying and turnover rate of oil must be done correctly, The important thing was fresh oil should never added to used cooking oil. This attitude is very bad.
Waste Vegetable Oil Survey Report, 2008
Starting in August 2008, members of private enterprise, local government and non-profit economic development collaborated to create a survey with goals to quantifying the waste vegetable oils (WVO) resources in the Algoma District. These range from volume of oil consumed in one week, or one month of operation timeframe, to more depth issues surrounding ann establishment’s interest in supporting local initiatives that would use the waste oil. The table below showed the results from various of business type in Algoma District.
This table shows the average volumes of waste oil generated by respondents and also projected waste oil generated per month for each type of restaurant in Algoma District. Steak House, Fast Food and Italian food generated the largest portion of WVO among the survey. Another issue involves franchise restaurants. The author stated that this survey provides a profile of total used cooking oil that produced in Algoma. It also identified a generall positive public response to the idea of a local biodiesel initiative. To ensure better data collection, this research should be continuing with larger staff and food business restaurant operators. The author end the writing with word there is always room for improvement. In my opinion, this review paper provide good basis for future study of this resource. (Macleod, 2009)
M. Martin, R.Claudia, (2004). Biodiesel Book
10.1 Recycled or waste oils
Recycled or waste oils have evolved as very popular raw materials for the production of biodiesel, as they are inexpensive and offer the potential environment benefits of using substances which would have to be discarded of. The first references to the utilization of waste oils was made by Nye et al(1981), who reported on successful engine tests for methyl-ethyl-, and1-butylesters produced from used cooking oils. At the same time, recycled cookng oils was also studied as raw material for biodiesel production by M. Mittlebach, who later developed a commercial process for converting waste oil from households and restaurants as well as fatty (Mittlebach and Junek, 1988).
In Austria, recycled frying oil is now an established alternative source of fatty material for the production of biofuels. A large number of articles published on the use of waste oils as raw materials for biodiesel production impressively illustrate the growing importance of the feedstock world-wide.
Some research was conducted by Hossain and Boyce 2009 related the biodiesel production from waste sunflower cooking oil as an environmental recycling process and renewable energy (Hossain, Boyce, 2009). The current feedstock of production of biodiesel are vegetable oil, animal fat, and micro algal oil. Vegetable oil is currently being used as a sustainable commercial feedstock.
Unfortunately, only sunflower, palm oil, soybean, rapeseed, and peanut oils are preferred as potential alternative fuels for diesel engines among more than 350 identified oil-bearing crops. (Demirbas, 2006).
10.2 Waste Cooking Oil as Raw Material for Biofuel Production
The increase of virgin vegetable oil price has lead the problems to the biofuel manufacturing industry. An option with great potential such as used cooking oil recycling, which includes a variety of processes like pyrolysis and catalytic cracking, designed to transform used cooking oil into hydrocarbon products for use in the preparation for refined chemicals or fuels. From this review, this author aims to determine some properties of used cooking for the production of biofuel.
Preliminary analysis of used cooking oil properties via GCMS using capillary column shows n-Hexadecanoic acid and Oleic acid as the major compounds present in the used frying oil. The analysis for determination of volatile and moisture content with 3 replicates show an average of 0.02% moisture and volatile content, which the experimental procedure was based on MPOB Test Methods. (Fukuda, 2001)
10.3 Options relating recycling of cooking oils
Cooking oil recycling or purification companies also play a significant role in ensures the quality and also origin of the oils they use. They also only can process cooking oils supplied by certificated collection/transport companies. Cooking oil purification or recycling companies should be obliged to establish a quality control system which necessary for traceability of the end product to obtained. They must have legal license and appropriate certification.
In addition, the companies must analyses all the potential risks involved in their operations such as storage of cooking oils, purification treatments, handling, storage and transport of the recycled oil, as well as the operations process include collectors and transporters to ensuring the quality and safety of the purified products they will be delivering. The companies must register of all their activities, with quantity data relating to the total flow of fatty materials. They must have a suitable system for making tanks, drums and other containers to ensure the type of product contained can be identified at any time and errors avoided that could lead to break in tracing the end product. Any variations observed must be recorded with as much information as possible, the batches must set aside and the relevant authorities must always be informed.
Besides that, the fatty waste generated in the process of purification or cleaning tanks and containers must be disposed in an appropriate manner, bearing in mind its contamination level. For example, waste from tank cleaning, if it is good quality, may be used in feed provided its safety and quality is strictly controlled. Any waste generated must also be recorded and used for a purpose suited to its level of contamination. (Jose, 2000)
Biodiesel Production from Waste Sunflower Oil as an environmental recycling process and renewable energy (Hossain, 2009)
Sunflower (Helianthus annus) is one of the leading oilseed crops cultivated for the production of oil mainly used for human consumptions and can also been considered as an important crop for biodiesel production (Niatou et al, 2008)
This article journal focus on comparison the optimum conditions of fatty acids methyl ester (FAME) or biodiesel production from pure and waste sunflower oil through transesterification process using alkaline catalyst. In this research, the quality of biodiesel from used edible palm oil has been also analyzed and compared. The pure sunflower cooking oil (PSCO) was purchased from local grocery shop while the used cooking sunflower oil (WSCO) was obtained from restaurants next to University of Malaya campus by the author. The WSCOs were filtered under the vacuum pressure (11 bar) Potassium hydroxide, sodium hydroxide, magnesium sulphate anhydrous, methanol, ethanol to remove impurities.
The author compiled two important properties of PSCO and WSCO in table. The acid values expose the low amount of free fatty acids (FFA) in both types of oils. In contrast, WSCO has significantly high viscosity than PSCO. Both oils can be utilized as fuel in diesel engines, but the main obstacle to employ the oil as fuel is its high viscosity which creates troubles in atomization of the fuel spray and function of the fuel injectors.
In two case studies (Turkan and Kalay, 2006), it has been found that almost 90% of the total fatty acids of commercial sunflower oil are composed of two double bonds containing oleic acids. It has reported that the percentages of these two free fatty acids in sunflower oil are 23.9% and 66.1% consecutively.
From this review, we can conclude that the optimum conditions for biodiesel production from WSCO and PSCO have been studied. The author has proved evidence that waste cooking sunflower oil may be employed as a substantial source of biodiesel as fuel in diesel engines. Moreover, this author research represented that the production from PSCO and WSCO has no significant differences. Biodiesel from used cooking oil could be used as diesel fuels which considered as renewable energy and environmental recycling processes from waste oil after frying (Hossain, 2009)
Transesterification of Biodiesel from waste cooking oil using ultrasonic technique (Darwin Sebayang et al, 2010)
The goals of the author of this research aim to explore a new transesterification process from waste cooking oil to biodiesel using ultrasonic technique. The local disposal of cooking oil becomes hot issues because of the large volume production of cooking oil. Malaysia have hundreds of these food business operators in Malaysia including fast food business outlets. Waste cooking oil is one of alternative source for biodiesel production.
Biodiesel from waste cooking oil (WCO) can reduce the cost of biodiesel production since the feedstock costs constitutes approximately 70-95% of the overall cost biodiesel production. (Chhetri, 2008). Biodiesel can be produced by the transesterification of triglycerides with alcohol usually methanol in the presence of a base or acid catalyst into fatty acid methyl esters (FAME). Conversion of triglycerides (TG) to FAME using ultrasonic obtained 95.6929% with the methanol to oil molar ratio of 6.1 and 1% sodium hydroxide catalyst.
Local Repeatedly-Used Deep Frying Oils Are Generally Safe (Tony Ng, 2007)
A review of this journal paper indicates that food scientists and health authorities in Europe are really concerned about the health hazards of oxidized products and lipid polymers formed in repeatedly-used deep frying oils. Promotion of Hazard Analysis and Critical Control Points (HACCP) certification and getting of food regulations to limit the polar compounds (PC) content in frying oils have been introduced in these countries to protect the health of citizen. Meanwhile, simple gadgets/test kit are available to monitor the quality of the frying oil.
Are repeatedly–used deep fryng oils safe?
This is the curious questions which are largely unanswered by the global scientific community. Nowadays, interest on the health impact of use of repeatedly-fried oils was begin to aware by public and features writers of the local pres-quiried the fate of such used fried oils from local franchised fast-food business. It is well-established that the frying oil used deteriorates in quality with frying time, accelerated by the formation of oxidized and polymerized lipid in the frying medium. Frying fast-food business or industry, a batch of frying oil is discarded anyway from 1 to 4 days depending on the operation hours is reported in the literature. In Japan, it has been reported that restaurant frying oil used for about 3 hours daily at 180°C . None information is available for the local scenario and this should form food for thought for our local food business operators.
In the early research, the author also refer case study from another scientist that do experiment on laboratory rat. This rat was fed with high concentrations of heated fats and oil. The result is obtained and the rats showed retarded growth, diarrhea, enlarged livers and kidney, and elevated metabolic enzymes (Crampton, 1951).
Another author also do the experimental work on white rat model. The result was shown that the long-term consumption of vegetable oils which contain 25% polar compounds induced adverse effect similar to those observed in earlier studies using severely heated fats.
What changes occur in the oil during the frying process?
During deep-frying of food at temperatures in the region of 170°-200°C, the oil used come under a heavy three-prong attack, namely :
Hydrolysis – Moisture from the food being fried vaporizes and hydrolyses triglycerides ( TGs) in the frying oil to glycerol, free fatty acids ( FFAs), monoglycerides (MGs) and diglycerides ( DGs)
Oxidation – Triglyceride molecules in the frying oil undergo primary oxidation to unstable lipid called “hydroperoxides” which cleave to form secondary oxidation products which comprise non-volatile and volatile compounds. Some of these secondary products polymerize (tertiary oxidation), increasing the oil viscocity cause browning on the surface, and darken the oil.
Thermal Polymerisation – High tempearatures of the frying operation produce high molecular cyclic fatty acid (FA) monomers, and TG dimmers and oligomers.
Several chemical and physical processes flow begin with the food being fried absorbs oil as well as releases some of its own lipid content sometimes coloured into the frying medium. After that, food particles and lipid cause browning darkens the oil. The immediate environment of the kitchen areas gets unpleasant smell especially when the smoke point of the frying medium is exceeded.
What happens to these discarded oils?
Elsewhere abroad, especially in Japan there is a market for such oils which can be recycled as biofuel or heating fuel. When there is no market or collection system for recycling of this waste vegetable oil (WVO), the staff of the establishment would probably take them home for further edible use.
Available from the data recommend that frying oils used in the preparations of fast-foods in local night markets and restaurants should contain polar compounds (PC) levels within safe-limits; below the UL of 25%. The stringent rule need for high quality fried products to meet customer expectations about their human health. The data in this review also suggests that a batch of frying oil used to prepare fast foods at around 180°C , with no top-up with fresh oil, should be discarded at or before the end of 3rd day. Overall, the evidence proved did not give reasons to refute that local repeatedly-used deep frying oils may be regarded as generally safe to human health.
How long does it take frying oil to attain 25% PC content?
The time that take frying oil to attain 25% PC content depends on the frying temperatures used, the content of moisture in the food being fried and whether there is topping up of the used frying medium. In the reports of Ng, it took 9 to 10n daily five-hour cycle of frying at 180°C n a commercial type fryer with a specific surface of 0.064cm/g oil and with no food added nor topping-up with fresh oil to reach a PC content of 25% (Ng, 1987).
Meanwhile, in the study conducted by Razali and Badri, it only took 3 days for the frying media used (palm oil, soybean oil) to reach a polar compounds (PC) content of 25% when frozen French Fries were intermittently fried at 180°C for 4 minutes per batch for a total frying period of 8 hours a day over 5 consecutive days. It also reported that polar compounds content in the fried food resembled that of the frying medium. The continuous use of the fryer at 180°C for 15 batches of fries an hour or 120 batches of fast food over 8 hours a day showed that the rate of formation of polar compounds in the frying oils used was much faster in the presence of moist food compared with the situation in the absence of food reported by Ng.
Besides that, in the study of Fauziah, the polar compounds content in palm olein and high oleic sunflower oil was lower at about 15% after 5 consecutive days of intermittent frying with raw potato slices at 180°C equivalent to 8 hours frying time per day. It is related that at the end of the cumulative 40 hours of frying at 180°C , the repatedly used frying oil is still safe for re-use asi its polar compounds content is still far away below upper limit of 25% to 27%. The corresponding polymer content of both used frying oils approximately a low 1.0 % (Fauziah, 2000).
Meanwhile, a case study in Japan, Totani reported that the polar compound content in campus-restaurant samples of frying oils which have been used at 180°C for 3 hours a day for 5 consecutive (total 15 hours frying time) was in the range 4% to 14% within in safe limits. In the same report, the polar compounds content in the batter coatings of 50 samples of commercially deep fried purchased randomly in Kobe, Japan ranged from 3.3% to 27.0% with 2 samples exceeding the upper limit of 25% polar compounds (Totani, 2006)
Oil degradation compounds (Jose, 2000)
This paper is review paper about oil degradation compounds in perspective of the health, International and the administration have issued recommendations and legal provisions which regulate the use and maximum life of oils and fats subjected to frying. The most commonly system for control is the parameter called Total polar compounds should be < 25% in Spain, Belgium, France and Italy, while <27% in Switzerland, Austria and Germany and <30% in Hungary.
However, the legislations of some countries also requires other parameters to be met such as acidity index should be <2.5 in Austria, Belgium and Japan. The determination of dimmers and polymers of tris acyl glycerols must be <10% in Belgium and Czech republic and < 16% in Holland. Furthermore, the author also found some case studies on actual samples from market corresponding to different types of cooking oil. Provide useful information in these studies might be found normal values in different degradation compounding discarded cooking oil. All these samples were taken by the inspection services of the administrations.
The final results from these case studies, used cooking oil has reached around 25% polar compounds with average values of 15.8% of polymers, 6.3% of oxidized triglycerides, 2% diglycerides and 0.9% free acids. Finally the conclusions of the author of these studies conclude that there is general lack of knowledge of the frying process, incorrect procedures for discarding oil also lack of frying temperatures and selection of conditions regarding the oil used.
Heated vegetable oils and cardiovascular disease risk factors (Chun-Yi et al, 2014)
Cardiovascular disease (CVD) is one of the leading cause of morbidity and mortality in the world. The example of CVD is heart attack, high blood pressure and stroke. It may result from many factors including lifestyle and dietary habits. Vegetable oil is one of the essential dietary components in daily food consumption. However, the benefits of vegetable oil can be deteriorated by repeated heating that leads to lipid oxidation. Thermal oxidation yields new functional product which may potentially hazardous to cardiovascular health.
Consumption of repeatedly heated oil has been shown to increase blood pressure and total cholesterol cause vascular inflammation as well as vascular changes which predispose to atherosclerosis. The harmful effect of heated oil oils is due to lipid oxidation during heating process. Oxidation of oil occurs when frying process is done in an open air. The free oxygen molecules react with unsaturated fatty acids via typical free radical mechanisms. Then, hydroperoxides as the primary products are formed due to oxygen attack that produces many other compounds with conjugated diene groups. The alkoxyl radical, which is formed via scission of O-O bond on of the hydroperoxides, further produces aldehydes, hydrocarbons, semi-aldehydes and acids. In excess oxygen, alkoxy and peroxy radicals form dimeric and oligomeric compounds (Nawar, 1984). Most of these by-products are carcinogenic. It was reported that Europe banned the consumption of re-used waste cooking oil as animal feedstock due to carcinogenic compounds (Cvengros and Cvengrosova, 2004).
Chapter 3
Result and discussion
The upper raw table showed the 20 chosen cafeterias from 39 cafeterias in University of Malaya including café that are located in student’s residential areas, faculties and students lounge areas. The data were collected, evaluated, analyzed and depicted in the form of pie charts. We can see that 9 of cafeteria consumed 21-30L cooking oil per day.
For residential college, mostly they start their operation time on evening from 5p.m until midnight meanwhile Perdana Siswa Complex and faculty, their run their business from morning only until 5 p.m. on Food Court Village, there are many of food stalls. Some of them only opened morning and closed on evening while some of them open on evening and close on midnight.
The answer of the questionnaire is depicted in pie chart. 20 respondents from 20 cafeterias that willing give their cooperation to do this survey. The age of respondents ranged from 24 to 55. Mostly of them are from the owner of cafeterias and some of them are worker. Most of cafeteria owner are Malays. Mostly of them claimed to use palm oil or corn oil for frying food.
The first pie chart is about result percentage of cooking oil consumed per day per volume by 20 chosen cafeterias. While the second questions is about percentages of frequencies cooking oil used repeatedly followed by questions percentages of method disposal of used cooking oil and the last questions from this survey is about the level of knowledge of repeated usage of cooking oil towards human health.
The figure displays the percentages of waste cooking oil consumed per day by 20 cafeterias in University of Malaya. The highest percentage was 45% by 9 cafeteria that answered they consumed 21- 30L of waste cooking oil per day. Mostly the respondents cannot estimated the real value of waste cooking oil while 30% consumed more than 40L and only 25% of them consumed 10-20L per day. There are 90% of the respondents preferred utilized the cooking oil in plastic bag pack because it more economically and they can save budget.
This figure shows the frequencies of the oil being used repeatedly. There are 75% of the respondents from 20 cafeteria admitted that they re-used the waste cooking oil for 2 times. 15% of the respondents re-used for 3 times and only 10% from respondents consume all cooking oil or used only one. This indirectly shows that not many of them really aware regarding the toxicity of the waste cooking oil. Some of them admitted that they re-used cooking oil repeatedly for deep frying food and some of them give respond because they want save and not waste the oil.
Frequent repeated usage of waste cooking oil could be due to lack of knowledge and information regarding the danger and health issues. Due to repeated heating, the quality, smell, color and taste of cooking oil changed due to the formation of polymers and polar compounds. The process will oxidize the lipid content to potentially toxic lipid peroxidations products. The resulting lipid hydroperoxides decomposes to highly cytotoxic products. Cooking oil may also has contaminants such as Polycyclic Aromatic Hydrocarbons (PAHs). These contaminants, if present in cooking oil, may be concentrated upon heating. Some PAHs have been found to be potentially carcinogenic to humans.
This figure shows the results of method disposal of waste cooking oils by cafeterias operators. 50% of respondents admitted they discarded the waste cooking oil directly into sink or drainage. They give excuse that the amount of oil is little. 35% of them answered they will collect, poured the waste cooking oil into bottle and thrown with normal waste if the amount of waste cooking oil stills half. One of cafeterias admitted that sometimes they will throw into river behind their cafeterias but not always. 15% of cafeterias operators sell their waste cooking oil to some recycling or waste treatment companies with price RM1 per 5 kg.
The cold temperature of water causes the oil to solidified and finally clog the drainage system, which indirectly pollutes the water-bodies (Kulkarni and Dalai, 2006). The disposal of waste cooking oil onto the soil could change the color of the soil, convert the pH of the soil to alkaline and deplete the nutrients such as carbon and nitrogen (Marjadi and Dharaiya, 2010).
The collected used cooking oil should sell to recycling companies or wastewater treatment. University of Malaya need to encourage the cafeteria operators to sell their used cooking oil to the recycler. The government also need to supports recycling of used cooking oil as it reduces the dependency on landfill sites and the use for biodiesel production.
Usually, the recycler will collect the used cooking oil and sold it to biodiesel companies. Some of researcher also will purchased cooking oil from the cafeteria to use for their project. In Japan, waste oils and fats were discarded from various site such as households, restaurant, cafeteria including food manufacturing industry. In Malaysia, there are many recyclers of cooking oil but in food commercial industry not from household. On 2011, Petaling jaya, Selangor has initiated campaign to encourage the recycling of used cooking oil into biodiesel also campaign “say no to polystyrene”.
Some of the recycler of used cooking oil will sell the oil into Sime Darby Plantation. Sime Darby is one of the top companies in Malaysia also in global. Sime Darby is responsible leading for the production of palm biodiesel in Malaysia and exported to overseas. In the non-food sector, Sime Darby Plantation is involved in the manufacturing of oleochemicals and biodiesel.
Sime Darby Plantations has two biodiesel plants located in Selangor, Malaysia. They are in Teluk Panglima Garang with annual capacity of 30,000 tonnes and also in Carey Island with capacity of 60,000 tonnes. Emery Oleochemicals is jointly –owned by Sime Darby Plantations Sdn Bhd and PTT Chemical International Pte. Ltd. Of Thailand.
Recycling of waste cooking oil is appreciated because it not only reduces environmental problems but also develop process economy by reducing the cost of raw material for biodiesel production. It should be promoted more on Malaysia and worldwide.
This pie chart displays the percentage of level of knowledge regarding the usage of repeated used cooking oil towards human health among the respondents. 50% of the respondents acknowledge that they not sure the effects of repeated usage of cooking oil is malicious to human health. 30% of the respondents said no while 20% of the respondents said yes. Mostly the respondents from Faculty of Science said yes, they know that repeated used cooking oil will cause negative effect to human health even though they don’t exactly know why it is. Process of repeated heating will oxidize the lipid content to potentially toxic lipid peroxidation products (Kubow, 1992). High awareness of this issue is important because it had been proved that effect of degradation of re-use of vegetable oils is an independent risk factor for hypertension (Soriguer, 2003). Since majority University of Malaya mostly students, their human health impact depend on the way cafeteria operators handle cooking oil.
Almost of the cafeteria operators interviewed not followed any official or unofficial guidelines, directives and instructions regarding the proper management of usage cooking oil. None of the also never go any training or proggramme involved proper management of used cooking oil. But some cafeteria such as cafeteria in Faculty of Science, they know about that from newspaper regarding the dangers of using repeatedly cooking oil also some lecture told them to practice proper management of used cooking oil and they also sell their recycling oil to some recycling companies.
There is also lack of knowledge on the proper frying techniques among the cafeteria in University of Malaya. The respondents were asked whether they followed any guidelines when deep frying food using cooking oil. All of them replied that they did not follow any guidelines at all. This show the negative attitude of cafeteria operators regarding to the usage of repeatedly heated oil, since they think that as long as the color of the oil looks acceptable, it is alright to use the oil continuously, even to be kept for the next day for frying another batch of food. Of course, it is very bad practice.
Recommended optimal frying temperatures are around 180-185°C. Frying at lower temperatures will result in longer frying times and lack of crust formation on fried food surface, which would increase the total absorption of fat into the fried food (Ufheil, 1996). Standardized frying temperature should be implemented to and adhered by all food operators. By ensuring every food operators possesses and makes use of a frying thermometer and providing a guideline an training on frying temperature that has to be complied by food operators could potentially improve the health of the general public.
Another important issue that we can discussed is about the practice of replenishing cooking oil with partial fresh oil is associated with significantly elevated levels of oil degradation products which can be carcinogenic (Morley, 2002). There is currently no standard guideline to measure the quality of cooking oil also how long and how many times the cooking oil is used before being discarded it. This is a good idea why a standard regulation on food frying techniques should be imposed on food operators in Malaysia.
In other to solve these issues, it had been suggested that several criteria can be observed in order to measure the quality of cooking oil. The criteria include observations regarding the crude color of oil, foaming, appearance of smoke, odor of frying oil, length of time used and taste evaluation of the restaurant especially fried food restaurant (Stevenson, 2006).
The Peroxide Value (PV) is a useful measure of oil quality. The PV is one of the most frequently determined quality parameters. It is an index to quantify the amount of hydroperoxide in fats and oil. Hydroperoxide is present when the oxidation of fats and oils occur during frying (Gotoh, 2006). When cooking oil is heated, the PV is increase. However, peroxides also rapidly decomposed at high temperatures. It has been reported that weakly oxidized fats and oils at levels of only 100mEqO/kg of PV can be neurotoxic. It is important to make sure the quantity of hydroperoxides in cooking oil remains low to ensure the safety of fried food.
In addition, PV values can be differ widely according to the type of food that is deep fried. PV values of oils can be very low after deep frying fruits, vegetables and other plant-based products such as potato chips. Meanwhile PV values of oils can be very high after deep frying meat-based products such as fried chicken, ‘keropok lekor’, fish cakes and sausages. The different brands of oils used by different cafeteria, the types of oil used and the types of utensils used for frying also have a great impact on the PV of cooking oils after frying food. These various factors contribute to the huge difference in the PV of cooking oil that were used for deep frying (Choe, 2007).
In this research, they are none of laboratory work, so they are no data about the measuring of used cooking oil PV. Further survey should be done to get significant data of peroxide value of used cooking oil.
During this survey also, the cafeteria operators were asked whether they would like to obtain more information and training practice on this subject, which include proper management of used cooking oil also detrimental effect of using repeatedly cooking oil, more than half respondents said they like to. It is shows a good attitude of cafeteria operators in University of Malaya to have improving their knowledge in healthy lifestyle.
Therefore, apart from lack of awareness campaign in the mass media, which might not reach the uneducated cafeteria operators, health officials and personnel should go to the field and educate them. Because not of them interested to read newspaper or follow mass media. In order to improve knowledge, more awareness campaign about this matter should be highlighted in the mass media. In order to change practice, voluntary training on the proper techniques of deep frying should be provided. Government also can provide funded vocational schools that provide catering course. It can be the basic steps towards proper management in food operators industry.
There are some options relating to food safety and quality control suggesting by (Jose, 2000). At begin of control is requirement for all agents in the chain organization (from waste oil collector to manufactures of fats for feeds to have quality control system such as HCCP or similar. This will ensure traceability and minimum variability in obtaining standard quality and safety for fats intended for feeds.
Furthermore, tools must be used for quality control to assessing the level of quality of each product. The analytical of such oils and fats will thus be directed differently. The control of used cooking oils will be based on the parameters established for the control of the products and the characteristics of the oils collected will assessed to their state of degradation. Also the percentage of water incorporated, particles or foreign impurities from the fried food and possibly the presence of harmful contaminants. Meanwhile, the control of recycled oil and their blends will be based on parameters established for the control of the products. These parameters will need to be stricter in order to be able to assess.
Chapter 4
Conclusion
For the conclusion, 45% average of 20 cafeteria operators throughout University of Malaya consumed 21-30L cooking oil per day. In terms of disposal method of used cooking oil, half of them were directly poured into the sink while only 15% of them take environmental alternative by sell used cooking oil to recycling companies. The respondents also admitted that they usually use cooking oil more than one time because of budget constraints. From this survey also, it proved that there is severe lack of knowledge and awareness about proper used cooking oil management among the cafeteria operators in University of Malaya. The level of knowledge of cafeteria operators including staffs, students in University of Malaya especially regarding awareness of repeated usage of cooking oil towards human health need to be improved. The author has some recommend how to overcome this problem.
For sake of Malaysian health, the media played the main role to more publicity and exposure about health issue and improper used cooking oil management that has become common among community. Research regarding food business operators awareness on the dangers of consuming repeatedly heated cooking oil are lacking. Further survey should be done in order to achieve more significant result of the questionnaire survey. More strict policy and inspection towards food business operators should be done by authority government to make sure they practiced proper management to their customers. The food inspectors should also should prohibited food operators from replenishing cooking oil by partial replacement of fresh oil. Oil should be filtered regularly using filter aids during daily frying in order to maintain the good quality of frying oil. The cafeteria operators need to changes to positive attitude and practice regarding usage of repeatedly heated cooking oil.
Besides that, many of the customers not aware of the danger of using the repeatedly heated cooking oil. Only small among of them are aware about this situation. This small portion needs to be bigger who well aware of this situation. This can be achieved in many ways such as by doing campaign related to health and negative impact of repeatedly used cooking oil. They also can spread of words regarding this consequences issue to relative, friends and family members to improve the awareness between Malaysian people.
Recommendation
More than half of respondents admitted that they usually use cooking oil more than two times because of budget constraints. Proactive action must take by the university to make sure the students health. Below is some recommendation to change toward proper management of used cooking oil including attitude of food business operators to make sure they served the best for the students.
-Do the collaboration with Department of Development and Estate maintenance of University Malaya (JPPHB) to do more inspection towards cafeterias in University of Malaya.
-More programme regarding the proper management of used cooking oil are needed to increase their knowledge and awareness such as talk, workship for food business operators.
-Educate with organizing talk or poster presentation from respective company or lecturer about the negative effect of repeated usage of cooking oil towards human health are importantly needed for all include food business operators, their worker staff and also students.
-Contract signed with some of recycling companies or wastewater treatment companies to collect the used cooking oil in cafeteria throughout University of Malaya. So it can encourage the food business operators to keep their used cooking oil in bottle and not thrown directly into sink or drain.
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