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GM WHEAT
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GM WHEAT
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 TA01 group 1 Group Leader: Celia Jong
Members: Soon Wanli
Raine Ong
Kimberly Tan
Liu Maopei
Khoo Zhisin
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Wednesday, July 14, 2010 @ 9:27 PMOur reflections for package 1 & 2! :)
Zhisin's Reflection
Food safety project is rather different from other projects that we've been doing for the past few semesters. I find that the introduction of this Food Safety project at this period makes it rather challenging. Each group member is attached to different companies for their SIP and this makes discussion between members more complicated. Due to some members who are attached to overseas companies, discussion between members ought to be online or through emails only. This not only slows down the progress as we have to wait for each other’s reply daily, and also there's misunderstandings here and there. To solve all these problems, I have to be patient with replies and also make my statement clear to others. I’ve also learnt to speak up more if I need help. Nobody will knows what I want if I did not say. For example, in this project, we need to find a product in any of our company and try to get their recipes. At first I was quite scared of my colleagues and dare not ask any of them. Later did I know that actually they’re quite friendly and even corrected my draft that I did for the flow chart. This project not only builds up our communication skills but also increases my knowing on my company’s product knowledge. I've learnt that high treatment like retorting can kill most microorgnism and at the same time enhance the shelf life of products. During this period, I’ve learnt to plan my time more wisely and manage it well. Though the working hours had tired all of us out, but as a team, I felt motivated and do my part well to help the group as much as possible. As a member of the team, I've to do my part on time so I wont affect other's part and add on the burden to others.This improves my team skills and cooperation with my fellow classmates too. Kimberly's Reflection As the packaging of our product is retort pouch, I’ve learnt and understand more about retort pouches through this package. There are only a few products in the market that uses retort pouches as the packaging for products in the market, therefore, through this package, I can understand why the military has been used these retort pouches to package their food. These retort pouches are able to withstand retort temperature and pressure, puncture resistance and able to lengthen the shelf life of the product. Therefore, it is ideal for army men as they may have to rely on these foods during harsh conditions. Moreover, retort pouches are also very convenient when it comes to heating it up. Through this package, I’ve also learnt how to identify hazards, critical control points and how to suggest preventive measures. I’ve also learnt more about products recall which is very important in the food industries. When the product contains harmful substances that would harm the health of the consumer, we should follow the standard procedure of product recall to try to recall the products as soon as possible to reduce the damage and to protect the safety of the consumer. Thus, this is something new and interesting that I’ve learnt. As everyone was busy with their work, I felt that we still made an effort to check the messages in the blackboard discussion forum and do up the allocated job within the deadline. As 2 of my group members are not in Singapore for their internship, I greatly appreciated their enthusiastic towards the project. All members were very proactive in contributing their help in finishing the project together. All our group members were very corporative and supporting of each other and we shall work hard together for the next package! All in all, I’ve learnt a lot from my group members and from this package. Package 2 is more research based. I was very excited to cover GM products as I have heard a lot on GM food. After researching on GM wheat, I've learnt that there were many constraints on GM wheat. There were also many disputes on the GM food too. I can feel that GM food is going to be more common in the market in the future years.This is due to the increase number of drought, floods and weather conditions that affects the growth of normal crops. Therefore, the need for GM seedlings is important as their genes are modified to withstand these harsh conditions in order to provide sufficient food for the people. All these GM food can only be excepted only if they are proven harmless to the human body. Therefore, more research should be done to prove this. I'm task to research on the toxins that wheat produces. Upon researching, I've learn many things. Things like the type of fungus that affect the wheat and the different type of toxin that they will produce. Moreover, I also get to learn the procedure to detect such toxin. I also learnt the dangers of such toxins. I've learnt some of the toxin in some subjects but not the dangers of these toxins. I got to understand the importance of detecting these toxins to prevent it being sold in the market. This time round, there wasn't much discussion between our members as the work is divided equally to them. Therefore, they are expected to research on their part. As the deadline of the report is nearing the end of our internship, there were quite a number of struggles. The workload of our job increases as we are expected to finish up our intern projects and this project. Luckily, we managed to finish it in time with the help of all the members, finishing the report in time. Celia’s Reflection The whole working together as a team when 2 of our group members are overseas were initially difficult to organize, plus the fact that it is hard to get everyone to meet as a group online together. But I manage to divide the work accordingly and everyone worked really well with their task at hand with the help of the blackboard and discussion forums. Package 1 has made me learn more about the process steps for retort pouch. The different ways the pouches could be heated up other than using water immersion, and they include steam with pressure, or water spray of pouches with hot water. But the most conventional way and most effective would probably be water immersion. At the same time, I was able to learn about product recall, and its processes, what is it for, why is it done and how it is done. We found out that defected goods have to be indeed taken off the shelves to protect the consumer safety. And it involves a series or process to recall the batch of goods. It was an interesting learning experience as we are all learning together. We also touched on good Manufacturing Practices, and found out what it is as well. That we have to ensure the good practices standards or the hazard could get to an unacceptable limits. After the induction package, it is much easier to get into the flow to fill up the HACCP form and to identify the CCPs, as initially, during the induction package, I totally forgot how this HACCP table flows and how to fill up. But thankfully after the induction package, my memory was freshened up and we were able to get the HACCP done as quickly for package 1. Overall this package has not only freshened all of our memories for HACCP and CCPs, at the same time learn more new things about Retort packaging, GMP and Product recall. In Package 2, it was a 100% self-learning process because i only know a little here and there about the GM products. Thus i not only need to rely on internet resources to find out about the ingredients that we are doing. I had to also look into TP Sparks resources, as well as the library books to read up on the process of GM crops, why it is done and how, its advantages as well as disadvantages. This is also to ensure that what i am reading is reliable and correct. GM products is now so readily available as well as improving daily, and it has its benefits and shortcomings, but it was definitely a breakthrough in food science that this kind of transgenic plants can be produced. Luckily, with each of us doing major research of one area, we are able to distribute the work evenly and learn with each other's research. I did more research on the DNA probe and Enzyme ImmunoAssays as well as other detection techniques available. I have learnt that today's technology has improved so much on the detection techniques and many people are focusing more on the issue of food safety. Because the current detection techniques can be done so quickly and more accurate with DNA probe...etc As a whole, i think we worked well as a group with a lot of cooperativeness, and although there were times that we debated over different research materials, we were able to resolved it without much issues. Overall i think we have worked very well within the team and as a team. Because there were a lot of factors that could have contributed to many mis-communications, but we managed to avoid all these. =) Maopei’s Reflection Through package 1, I am able to learn more about food safety regarding the HACCP process. What I had learnt previously during FPQA was to identify CCPs and stuff, not so much about the decision tree and all. Now, I am able to have a clearer picture of how does the HACCP system works. Furthermore, I am exposed another type of food packaging which is the retort pouch that I have no idea what is it about before this package. I got to learn more about product recall, preventive measures and etc through the info that my group mates have research on. On the other hand, as this module requires us to communicate online, I find it rather hard for all to come online at the same time and discuss it as a group together. This could be due to each of us are busy with our SIP/OSIP. Therefore I think that it is everyone’s responsibility in making an effort to check the discussion board at blackboard more often and reply accordingly. Although there might be times that communication breakdown occurred among us, I believe that if one is patience in explaining slowly, then the problem would be solved easily! Through package 2, I have a better understanding on what is GM food and other crops. What are the available GM crops that I can find in the market and stuff. This package enhances my learning on GM wheat and other crops as well. I think that the difficulties that i encounter was that mainly the websites/links that i found only talks about GM crops in general and not about GM wheat itself. Luckily after researching for a longer time and when i got a clearer view pf what is wanted for my part, I was able to overcome the difficulties. Not forgetting some helps from my teammates as well. :) Another difficultes that me and my teammates face was the blog. As all of us are not really experts in blog, standardising all the fonts and stuff really give us a big problem at a certain point of time. Fortunately, we are able to resolve it.Additionally, through this module, I have develop the habit of checking bb regularly. I think is every group member's responsibility to do so so that we will be updated on the latest process of the project. Raine's Reflection Through this package 1, I’ve learnt more about product recall, retort pouching and the procedures used in an actual food company. Not only that, it also requires me to use the knowledge that was learnt from FPQA and FPQAP examples such has the HACCP principles and table as well as the CCP decision tree. As that was done during FPQA, I actually forgotten some parts of how to do it but through Food safety it helps me to recall and apply in this package. Through package 2, I’ve learnt more about GM food in general as well as GM wheat in detail. As I was tasked to research about the history of GM food and who discovered it, I’ve learnt the history and the people that was involved in the discovery process of GM food. In the past, I had never known anything about GM food. However, through this package, it made me realized how GM food had been playing a part in our daily life, till the fact that I might have ate GM food before without realizing it. Not only that, through reading of my other group members’ research, it allows me to have better understanding with regards to the process, advantages, disadvantages, toxins involved as well as the microbiological problems with GM wheat. A difficulty I had faced through researching at the earlier stages was trying to find out the reason of the countries rejecting GM wheat and the countries that actually allow the growth of GM wheat. GM wheat, I must admit, has lesser information and harder to research since it is a product that has yet to be approved by consumers. Despite the challenges faced, I was still able to find out certain information through the internet. Not only that, since food safety is an online problem based learning therefore; communication would be the major problem for all of us since we had to communicate through the discussion board. As I am on OSIP, my only form of communication would be through the blackboard discussion board. At the initial stage it was slightly hard for us to get our message across for everybody but as the time goes by this problem has been reduced and I felt that our team dynamics was pretty strong and that we were able to work together and submit our work on time. Working with my team members makes it much more easier since all of us makes an effort to constantly add in ideas and discuss under the discussion board provided for us. Wan li’s Reflection Attempting Package 1 allows me to refresh on my memory and concept learnt during FPQA and FPQAP, regarding safety limits, HACCP, CCP, CCP decision tree as well as GMP. This time round, I am able to learn on product recall as well and more regarding GMP. Initially, my impression of GMP was more on cleaning and having hygiene practices during the manufacturing of food. Through the package, I was refreshed with the concept of GMP and learnt that it actually covers 5 areas; Building, Transport & storage, Equipment, Personnel & Training. I learnt that some of the processing steps were not taken as a CCP due to the GMP in place to control. As for product recall, I get to learn that there are actually proper procedures needed to be done, in order to conduct a product recall and under what kind of situation will product recall be executed. The product that my group chose was not something that I have done before or is familiar with. It was a great opportunity for me to learn more about retorting, the different methods and their strength and weaknesses. As well as regarding the retort pouch itself and process of making a retort pouch food. As I am based overseas over my internship, the only mean I have to communicate with my members was through online messenger or the use of blackboard’s group discussion message board. I must say that this is really a very good learning experience for me to work in a new way that I am not familiar with. To function in a situation where I cannot directly contact my members as and when I like. It allows me to have the experience to take care of work between two countries. Also, as I am the only member in my group based here, I really did not have any other people to discuss with. Thus, it pushes me to be accountable to update as much as possible and I also have to learn to manage my schedule well so that I can leave ample time for my members to reply to me and not squeeze everything till the very last minutes as the use of blackboard’s group discussion board is not something that we are always logged on on to get or give instant replies. On the hindsight, my group is cooperative and helpful and I can see the effort put in to get the work done. We will help each other after our own parts were completed and I also received help from my members in Singapore to contact another member to pass a message or instruction for me. I can see that teamwork, communication and understanding are very essential for a group to function well. Additionally, every member got to be responsible for their own task and at the same time, be willing to render help to those in needs. For package 2, genetic engineering was a topic that I thought I was rather familiar with but when I got started on doing it, I realized that actually, I do not know it very well at all. For example, I have known of the existence of GM wheat, which the product that my group selected, but I did not know that it was actually not used and sold in the market yet. Being an unavailable product in the market, made it harder for us to do our research as there is not as much information available compared to the other common GM crops. As most of us got busier with our own internship and other work, we could hardly meet online to discuss. Therefore, communication was also made harder, as we could only use emails and the blackboard group discussion board to converse and this usually takes time before a reply comes in, slowing down the progress. However, even though time is tight and communication was not that smooth, my group still managed to pull through and everyone put in their efforts to contribute towards the project. Also, I am given the task to find out how the GM processes was done and the categories of GM food available. Therefore, I have to research into online books to read up and one limitation about this is that, not the full content of the books can be view online. Therefore, I have to try and combined the information I have obtained and put them together to see if they actually match and flow or not. In additional, I did not really enjoy the process of reading those material as molecular and genetic biology is something that I find it hard for me to imagine and I had to re-read the information so many times to understand the process as they are rather technical and a number of biotechnology jargons was used. Nonetheless, through this project, I have definitely gained a lot of new knowledge and I have learnt to push myself into doing things that I do not enjoy but have to. This helped to train my level of discipline, patience and concentration in getting things done. back to top? |
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Tuesday, July 13, 2010 @ 10:09 AM Toxin
Wheat: First the fungi, and then the mycotoxinsWheat plants infested with fusaria fungi produce small, shrivelledgrains in their ears. Some fusaria species can also produce various fungal toxins (mycotoxins). These can contaminate food when the cereal is processed. Mycotoxins can cause chronic and acute symptoms of poisoning, depending on the type and quantity.
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Fusaria can normally be contained by selecting less susceptible varieties and using appropriate cultivation methods and chemical fungicides, thus reducing mycotoxin contamination. However, during severe infestations, particularly when the weather is hot and humid, these measures provided insufficient protection. Some new approaches have now been developed for producing fungus-resistant plants. They draw on molecular-genetic methods and findings. *The wheat developed by Syngenta contains a new gene from specific fusaria, which is responsible for "detoxifying“ the mycotoxins. *Specific bacterial genes that trigger the production of substances like chitinase or glucanase, which destroy fungal cell walls, have also been inserted into plants. This approach is being tested with fungus-resistant grapevines, which have been released in the Franken and Pfalz winegrowing regions of Germany since 1999. *Another concept exploits a natural defence mechanism which infected plants use to protect themselves and to prevent the spread of the fungal infection („hypersensitive reaction“). This method was used with potatoes to make them less susceptible to the pathogen which causes the infamous late potato blight (Phytophthora infestans). Mycotoxins  Fields affected with significant amounts of ear rot should be harvested and handled separately. Grain should be harvested as early as possible and dried to 15% moisture or lower. Usually, specific environmental conditions are required for mycotoxin production in pre-harvest grain. Being aware of these conditions and the amount of disease in the preharvest crop should help in judging the likelihood of a mycotoxin problem. Mycotoxins can be produced in storage; however, this situation is almost always associated with improper drying and/or storage conditions. Aflatoxin  Aflatoxin is a potent liver toxin and known to cause cancer in animals. In swine, aflatoxin can cause reduced weight gain, reduced ability to resist diseases, hepatitis. and death. The Food and Drug Administration (FDA) has established action levels of 20 parts per billion (ppb) for grain and feed products, and 0.5 ppb for milk. Grain, feed, or milk containing aflatoxin at or above these levels cannot be sold for food or feed in interstate sales. Mixing aflatoxin contaminated grain with sound grain for sale is illegal. Corn and other grain with less than 20 ppb aflatoxin can be sold as normal grain. Recommended limits in feed are: 20 ppb for dairy animals; 100 ppb for breeding cattle, breeding swine, and mature poultry; and 300 ppb for finishing cattle and swine.Aflatoxins are produced by the fungus Aspergillus flavus. This fungus causes a disease in preharvest corn known as Aspergillus ear rot. Aspergillus ear rot and aflatoxin are a concern mainly in drought years and are more commonly found in the southeastern and southwestern portions of the United States. Although Aspergillus flavus is a common fungus growing as a saprophyte on dead plant debris, infection and aflatoxin production in preharvest corn occur almost exclusively in years when plants are severely stressed by drought. Aflatoxin production in the field is favored by high grain moisture, temperatures in the range of 80-100 F, severe drought stress, nitrogen deficiency, and significant insect damage. Except in hot, dry years, aflatoxin in the Midwest is almost exclusively associated with improper storage of grain or feed. Aflatoxin production in stored grain should not occur if grain is sufficiently dried to 13-14% moisture and maintained at that level. Aspergillus ear rot Many times, grain is initially screened for aflatoxin by using a black light to detect kernels or portions of kernels that glow with a bright green yellow fluorescence (BGYF). This is strictly a presumptive test and indicates only that the causal fungus, Aspergillus flavus, was growing on the living kernel and does not indicate the presence of aflatoxin or other mycotoxins. BGYF is best observed in cracked corn rather than whole kernels. When examining corn for BGYF, one should have a color standard or an authentic BGYF for comparison. The causal fungus occasionally may be observed growing on kernels, but its presence does not guarantee that aflatoxin is present. Therefore, a chemical test is necessary for the actual detection of aflatoxin. Deoxynivalenol Deoxynivalenol is also known as vomitoxin or DON. This mycotoxin causes reduced animal feeding and weight gain (especially swine) at levels as low as 1-3 parts per million (ppm). Vomiting and total feed refusal does not occur until DON concentrations are much higher (> 10 ppm). The FDA has recommended that DON levels not exceed 1 ppm for human food. The following limits have been recommended: *10 ppm for ruminating beef, feedlot cattle and chickens, not to exceed 50% of the diet; *5 ppm for swine, not to exceed 20% of the diet; and *5 ppm for all other animals, not to exceed 40% of the diet. Gibberella ear rot  Deoxynivalenol is produced by the fungus Gibberella zeae, also known as Fusarium graminearum. This fungus causes Gibberella ear rot on corn and head scab on wheat. Gibberella ear rot is enhanced by cool, wet weather during the period just after silking. The disease is often more severe in fields where corn follows corn, or corn follows wheat, especially if the previous crop was affected with Gibberella ear rot, stalk rot, or head scab, and the infected residues were left on the soil surface. Prior to harvest, Gibberella ear rot is readily identified by examining the intact ears. The disease is visible as a pink or reddish mold at the tip of the ears when the husk is peeled back. If the disease is severe, the silk will adhere to the ear and may be reddish in color. Once the grain is shelled, it is difficult to determine by visual examination if the grain is infected. After harvest, production of DON is favored by grain moisture of 20.5% or more, and temperatures of 70-85 F. Grain containing DON also may contain smaller amounts of the mycotoxin zearalenone. Once the grain is harvested, growth of the fungus that produces DON is effectively halted if the grain is dried to 15% moisture or lower. Zearalenone Zearalenone is an estrogenic mycotoxin, and can cause infertility, abortion or other breeding problems when fed to swine. As little as 0.1 to 5 ppm zearalenone in a feed ration may produce estrogenic syndrome in swine. Also, uterine prolapse can occur in young pigs with concentrations as low as 1 ppm zearalenone. There have been no limits or recommended levels placed on grain used for human consumption. Zearalenone can be produced in preharvest corn or wheat by strains of Gibberallazeae (Fusarium graminearum), however it is usually produced in low concentrations. Often, both DON and zearalenone occur together. In stored grain, production is favored by grain moisture in excess of 20.5% and 70-85 F temperatures. As with DON, the growth of the fungus that produces zearalenone is effectively halted if the grain is dried to 15% moisture or lower. Fumonisin Fumonisin is a recently discovered mycotoxin that may be the cause of equine leukoencephalomalacia (blind staggers) in horses, donkeys and mules, and pulmonary edema in swine. There is also evidence linking fumonisin to cancer in humans. No restrictions are currently placed on food because little is known about the effects of fumonisin on humans. Fumonisin levels in feed are recommended to be no higher than 5 ppm for horses, 10 ppm for swine, and 50 ppm for cattle. The fungus that produces fumonisin, Fusarium moniliforme, causes Fusarium ear rot of corn, the most common and widespread ear rot in the Midwest: affecting as much as 90% of the corn fields. Diseased ears will have signs of the fungus growing on and between individual kernels or groups of kernels. The fungus will appear cottony white or light grey. Diseased kernels will become grey to brown. Fusarium ear rot  The conditions under which fumonisin is produced are not known. Fusarium moniliforme can grow over a wide range of temperatures and moistures, and some strains of the fungus are more efficient producers of fumonisin than others. The severity of Fusarium ear rot is greatest in dry years. Kernels that are infected with Fusarium moniliforme are more brittle than healthy kernels. As a result, these infected kernels break during harvest and drying, and end up in the screenings. For this reason horses and swine should not be fed corn screenings.Unlike the other mycotoxins associated with corn, high fumonisin concentrations have also been found in seemingly healthy corn kernels. Examination of such corn reveals that Fusarium moniliforme is present in these kernels, even though there are no visible symptoms or signs of disease. Because of this risk, horse owners would be advised to check for fumonisin using one of the commercial test kits. Sampling The first step in mycotoxin determination is the sampling of the grain. Particular attention should be given to the sampling procedure because sampling error will be the greatest source of variance in the analytical procedure. This variance is primarily due to the uneven distribution of the mycotoxin contaminated kernels within a lot of grain or feed. The ideal sampling procedure should assure the highest probability of detecting mycotoxins even when contamination is low. One method of sampling grain is to use a probe sampler. Since mold growth usually occurs in spots in the grain lot, best sampling is done on recently blended lots of grain. Another method of sampling is to collect small samples from the stream of grain as it is moved in or out of the bins. With both sampling methods, the collected grain is pooled into a large aggregate sample that represents the lot. For shelled corn, it is recommended that the aggregate sample be about 10 pounds. The aggregate sample should be coarsely ground. Most analytical procedures need only about 25 grams (0.9 ounces) of ground corn, so it is important that the aggregate sample be thoroughly mixed after grinding. A one or two pound subsample is then taken and it is ground to the texture of instant coffee. From this subsample, a final sample is taken for analysis. Mycotoxin Analysis Kits The most accurate and reliable method of analyzing mycotoxin levels is to send test samples to professional laboratories for analysis. This. however, is often not practical because of the cost or the time required for analysis. Because of the need for fast determination of mycotoxin levels, a variety of mycotoxin test kits are sold that are easy to use and relatively inexpensive. Before purchasing a mycotoxin test kit, it is important that one determine what type of information is required. Even though the technology in the analysis of mycotoxin kits is constantly improving, the information derived from the kits is basically of two types; quantification or threshold levels. A test kit that determines the exact amount of mycotoxin is needed by industrial grain handlers who must document the quality of their starting materials or finished product. Special equipment must be purchased that measures the mycotoxins levels. In contrast, livestock handlers often need to know only that the level of mycotoxin in their feed is below the threshold levels for their animals. This information can be obtained from kits that provide a quick yes or no answer at a specific threshold level of mycotoxin without the use of special equipment. Mycotoxin test kits work by one of two methods: thin layer chromatography (TLC) or immunochemistry. While the TLC method has been around for a long time, it has both advantages and disadvantages compared to the immunochemical methods. One advantage of the TLC method is that more than one mycotoxin can be tested for with a single kit. With the immunochemical kits, a separate kit must be purchased for each mycotoxin. A second advantage of the TLC method is that the mycotoxin is actually visualized. The immunochemical kits detect the mycotoxin indirectly and thus are more prone to error. Error can be reduced by purchasing test kits from reputable companies and carefully following the instructions.  The advantages of the immunochemical methods are their ease of use and the short time required for the analysis. For those who only wish to know that the toxin concentration in a sample is above or below the toxic levels recommended in animal feed, the immunochemical test kits are probably the method of choice.The following is a summary of mycotoxin kits from three commercial sources. These detection kits illustrate the different technologies being used. One should realize that these technologies are constantly being improved and that these companies are striving to make the detection kits more accurate, sensitive, easier to use, less expensive, and more rapid. Romer's "MYCOTEST" uses TLC technology. Corn samples are ground and extracted. The extracts are then spotted onto a TLC plate. One TLC plate can be spotted with extracts from several corn samples. The TLC plate is developed, dipped into an aluminum chloride solution and heated. The mycotoxins are then visualized by viewing the plate under long-wave ultraviolet irradiation (black light). Mycotoxin standards are also available making it possible to visually estimate the quantity of the mycotoxins present. The corn sample illustrated below contains aflatoxin at approximately three times the standard. Neogen's "AGRI-SCREEN" and "VERATOX" use ELISA technology. Antibodies specific for a mycotoxin are adhered to the wall of a microwell (1). A solution of mycotoxin, chemically conjugated to an enzyme, is provided with the kit (2). A corn sample to be tested for mycotoxin is ground and extracted. The extract is then mixed with a fixed amount of the mycotoxin-enzyme solution and placed into the microwell (2). The mycotoxin from the extracted corn sample and mycotoxin-enzyme conjugate then compete for binding to the antibodies in the microwell. As the mycotoxin in the corn sample increases, it competes with the mycotoxin-enzyme conjugate (3). The assay procedure measures how much of the conjugate actually binds to the antibodies by first thoroughly washing the microwell and adding a colorless substrate to it (4).The enzyme present in the microwell converts the substrate to a blue colored product; the more mycotoxin-enzyme conjugate in the microwell, the more intense the blue color. Because corn samples with high mycotoxin will result in less binding of the mycotoxin-enzyme conjugate, positive samples will be lighter blue (5). Determination of the mycotoxin is done by visual comparison of the corn sample with positive and negative controls. Quantitative measurements can be obtained if a spectrophotometer is available. Vicam Vicam's columns use immuno-affinity chromatography technology. The columns contain beads chemically fused to antibodies specific for the mycotoxins (1). A corn sample is ground and extracted with a methanol: water solution. The extract is then run through the affinity column and the mycotoxin sticks by binding to the antibody beads (2). Other materials in the extract do not stick and are washed off the column. The mycotoxin is then removed from the column using methanol (3). To visualize and measure the levelof mycotoxin, a derivative of the mycotoxin must be made and measured with a fluorometer. What to do if mycotoxins are present? Once mycotoxins are present in grain, there are no practical methods for decontamination. The grain should be stored separate from uncontaminated grain. Getting an accurate measurement of the mycotoxin concentration will help in determining how the grain can be used. If the toxin levels are not excessively high, on-farm blending of the contaminated grain with uncontaminated grain is an option. The contaminated grain also can be fed to animals that are less sensitive to the mycotoxin. Charles P. Woloshuk. Mycotoxins and Mycotoxin Test Kits. Retrieved June 21 2010, from: http://www.ces.purdue.edu/extmedia/BP/BP-47.html GMO Compass. (2008). Wheat. Retrieved June 21 2010, from: http://www.gmocompass.org/eng/grocery_shopping/crops/22.genetically_modified_wheat.html Federal Ministry of Education and Research. (2004). Fungal resistance: An attractive, but difficult objective. Retrieved June 7 2010, from: http://www.gmo-safety.eu/archive/180.fungal-resistance-attractive-difficult-objective.html |
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Monday, June 28, 2010 @ 6:13 AM Usefulness of GM Crops
Genetically Modified Wheat
Reasons why some of the countries reject GM Wheat
Uses of GM Wheat
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@ 1:53 AM Microbiological problems with GM wheat
 But those that could possibly be linked to wheat, this is it: (Research data are taken from GMO Compass website: http://www.gmo-compass.org/eng/grocery_shopping/crops/22.genetically_modified_wheat.html) Poisonous Fusarium infestations: New solutions with genetic engineering? Septoria, Fusarium, and common bunt are fungal diseases that often cause problems for wheat growers. These fungal diseases can spread rapidly when conditions are mild and moist. One disease that poses particularly serious problems is Fusarium. Infected ears will either fail to produce grains or will produce grains that are small and stunted. Problems with Fusarium, however, don’t end there. A crop affected by Fusarium infection can also contain dangerous substances that can impact the health of humans and livestock. Certain strains of Fusarium produce mycotoxins. Mycotoxins is a general term for poisonous compounds produced by fungi, which are thought to protect germinating spores from microbial infection. Mycotoxins remain in food during processing and can lead to chronic and acute diseases. In high concentrations, they can cause nausea and vomiting. Certain Fusarium toxins are implicated in cancer and have been known to affect hormonal balances. Right now, there is no efficient way of stopping Fusarium infection. Although management strategies using resistant cultivars, crop rotation, and chemical fungicides are helpful, they are still not enough to stop the disease when conditions are conducive to infection. Fusarium is responsible for yield losses and mycotoxin contamination in wheat grown around the world. Genetic engineering opens the door to new strategies for managing Fusarium and other fungal diseases. Scientists are currently developing genetic approaches to conferring resistance to fungal diseases and are testing their effectiveness on wheat. Field trials are underway in many countries, including countries in Europe, to find out if experimental GM wheat plants are actually resistant to fungal infection and thereby produce grains won’t be laden with dangerous mycotoxins. GM wheat has resistance against pathogens • fungal resistance, in particular against infections with fusarium or mildew. Infestation of plants with these fungi can lead to contamination of the wheat products with strong toxins ( mycotoxins). Resistance against smut fungi (Ustilaginomycetes; loose smut, stinking smut). Fungal Resistance Fungi are responsible for causing many plant diseases. Genetic engineering is being used to create fungus resistant crops. For some plant species (potatoes, maize, cereals, grapes) fungal infestations - e.g. blight, grey mould, or Phytophthora - can lead to significant yield losses. Fungal diseases are usually combatted with chemical fungicides or heavy metal compounds (e.g. copper vitriol). For some crops, fungus resistant cultivars have been developed using conventional breeding methods. Intensive work is underway to develop transgenic plants with acquired fungal resistance. So far, none of these efforts have resulted in commercially viable varieties. Several approaches are under investigation: • Transfering bacterial genes encoding anti-fungal enzymes, e.g. chitinase or glucanase. • Transferring genes for anti-fungal substances already produced by some plants. • Augmenting the hypersensitive reaction: Many plants cause individual, infected plant cells to die at the site of fungal infection, effectively stopping the infection in its tracks. This mechanism can be recruitred or enhanced by genetic engineering. Virus resistance Viruses cause many plant diseases and are often responsible for extensive crop losses. This makes virus resistance an important goal for crop improvement. Although chemicals can be used to manage most plant pest and diseases, there are no practical ways of eliminating plant viral infections. In some cases, pesticides can be use to manage insects that spread viruses. Virus resistant varieties of some plants have been developed by conventional breeding techniques. Various strategies can be used to achieve virus resistance with the aid of genetic engineering: • Viruses are enclosed by a protein coat composed of what are known as capsid proteins. If a plant is genetically transformed with a virus' capsid protein, it can be made resistant to the respective virus. All virus resistant plants commercially grown today are based on this concept. • Other concepts target cell to cell virus movement or virus reproduction. • Genes taken from plants that are known to produce antiviral proteins may be transferred to crops. Glucanase Enzymes that break down glucanase Glucans are important structural compounds in the cell walls of plants and fungi. Chemically, glucans are a type of carbohydrate. They consist of the same basic building blocks (monosaccharides) as starches, but the units are arranged differently. Many microorganisms produce glucanases, which enable them to digest glucans and use them as a source of nutrients. Industrially, bacteria are used to produce glucanases on a large scale for use in applications such as beer brewing. Glucanase supplements help beer yeasts break down glucans in barley, which can often block filters. (In Germany, glucanase additives are not permitted because they do not conform to the German Beer Purity Act.) Genes for certain glucanases (usually b-1,3-glucanases) have been transferred to plants to enable them to degrade the glucans in disease-causing fungi. Researchers are developing grapes, wheat, and barley with glucanase-conferred fungus resistance. Genetically modified barley with a novel gene for glucanase can help improve the quality of animal feed. Some animals lack the glucanases needed to break down long chain glucanes present in barley cell walls. Therefore, poultry raised with barley without added glucanase remain small. back to top? |
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Saturday, June 26, 2010 @ 9:18 PM GM Wheat Modification Process
Once the desired genes are inserted into the selected organism, the new genetically engineered organism is reproduced to obtain a generation of individuals that possess the desired trait. These individuals in turn are raised and utilized with the desired gene actively functioning. Some examples are the S-adenosylmethionine hydrolase gene from a bacterium which was added to cantaloupe to control ripening, the Phosphinothricin acetyltransferase gene from another bacterium which confers Glufosinate (Roundup©- an herbicide) tolerance, and the potato that is insect resistant with the cryIIIA gene from Bacillus thuringiensis (Bt) sp. tenebrionis (another bacterium) (U.S.FDA, 2000). There are many other GMOs that have been produced and are being used for crop production at this time. There are 50 examples of genetic engineering reported by the U.S.FDA (2000). These GMOs confer resistance to pesticides, more uniform ripening, resistance to insects and viruses and improved protein content of several food crops. So why are there so many protests to genetic engineering? http://www.yale.edu/ynhti/curriculum/units/2000/7/00.07.02.x.html back to top? |
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@ 8:32 PM Disadvantages of GM wheat
  GM Food(Dis.): • Safety o Potential human health impacts, including allergens, transfer of antibiotic resistance markers, unknown effects o Potential environmental impacts, including: unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity • Access and Intellectual Property o Domination of world food production by a few companies o Increasing dependence on industrialized nations by developing countries o Biopiracy, or foreign exploitation of natural resources • Ethics o Violation of natural organisms' intrinsic values o Tampering with nature by mixing genes among species o Objections to consuming animal genes in plants and vice versa o Stress for animal • Labeling o Not mandatory in some countries (e.g., United States) o Mixing GM crops with non-GM products confounds labeling attempts • Society o New advances may be skewed to interests of rich countries GM Wheat (Dis.):
Environmental Risks of GM Wheat Like conventional wheat, GM wheat can cross-pollinate with conventional wheat and some weeds—creating, in the case of Roundup Ready wheat—a superweed that cannot be destroyed with herbicide. GM wheat can also contaminate neighboring fields by traveling through the air or with small animals and birds. Conventional and organic wheat can also cross-pollinate or become mixed with GM wheat in the environment or in grain handling system. Once wheat is contaminated, it would be virtually impossible to reclaim.
Agricultural Risks of GM Wheat A farmer who decides to plant genetically modified seeds must pay a fee and enter into a technology use agreement with the owner of the seeds, giving the farmer license to use the patented technology. Monsanto’s technology use agreement prohibits farmers from saving seeds to replant the next year or selling the seeds to another farmer to plant. The agreement also requires farmers to use specific herbicides in a company directed weed management plan. If the terms of this agreement are violated, Monsanto can impose fines as much as 120 times the technology fee paid by the farmer. This agreement releases Monsanto from liability for damages caused by the crops—leaving farmers liable if their crops contaminate a neighboring field. Monsanto has sued farmers when GM seeds were found in their crops, if the farmer did not plant or buy the seeds.
Health Risks of GM Wheat For the most part, health risks of GM wheat are uuknown. Since no GM wheat has been released, extensive studies on the affects on human health cannot be completed. Few independant studies of the safety of any GM foods have been done. Unlike other GM grains, such as corn and soybeans, wheat is grown primarily for direct human consumption—not processed into oils or used as livestock feed. Scientists warn that the consumption of GM foods in general might result in new allergies, resistance to antibiotics, inability for the body to absorb vitamins or minerals, and other health problems. Results of studies on animals fed GM foods include: cancerous cell growth, damaged immune systems, atrophy of the liver, inhibited development of their brains and livers, inhibited growth of blood cells, false pregnancies, sterility and mysterious deaths. The only human health study conducted found that a GM gene inserted into soybeans randomly transferred out of the soybeans and into the DNA of bacteria found in the digestive system. If this gene is allergenic or toxic to the human body its effects could last a lifetime. WORC. (2004, September). The Problem With Genetically Modified Wheat. Retrieved June 27 2010, from: http://www.worc.org/userfiles/file/Genetically%20Modified%20Wheat.pdf back to top? |
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@ 8:24 PM Advantages of GM wheat
Benefits of GM foods
GM advocates argue that genetically modified foods are potentially better for the environment. By using genetically engineered crops that are resistant to attack by pests or disease (insect resistant or IR), farmers and primary producers do not have to apply large amounts of pesticides and chemicals to the surrounding environment. Developing crops that are tolerant to particular herbicides (herbicide tolerant or HT) and pesticides may reduce the amount of pesticides used in food production and the residual pesticide levels in the environment. Benefits
Better Health Channel. (2010). Genetically modified foods
U.S. Department of Energy Office of Science, Office of Biological and Environmental Research, Human Genome Program. (2009). Genetically Modified Foods and Organisms Retrieve June 6, 2010, from
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