Detection and quantification of genetically modified soybean in tempe | |
| Author | Budi Prakoso |
| Call Number | AIT Diss. no.BP-03-2 |
| Subject(s) | Soybean--Genetic aspects Transgenic plants |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. BP-03-02 |
| Abstract | Genetically modified crops (GM crops) have been developed by application of advanced techniques of genetic engineering in plants. GM crops offer distinctive advantages like insect-, weed-, disease-, and drought-resistance, better nutritional value and higher yield. However in a considerable part of the world, non-governmental organizations and/or the general public are hesitating or opposing the cultivation and application of GM crops. There are many opinions about GM crops. Some reject, for various reasons, any use of genetic engineering for crop improvement. Others accept the GM crops and their products without questioning. In a more balanced opinion, genetic engineering for crop improvement is accepted conditionally, the gene inserted and its products should be carefully assessed both for human and environmental safety before release into nature and to the public market. Since GM seeds and food containing GM products cannot be distinguish by appearance from non-GM materials, the consumer has to be informed about GM containing products. Methods for detecting GM crops and quantification of GM products in food have to be developed in order to guarantee that correct information is passed to the consumer. Accurate detection of GM material is also required to enforce the law in countries that do not allow GM crop products or have set a threshold for GM crop content in food. Nowadays, Roundup Ready (RUR) soybean is one of the most widely grown GM crops in the world. Many papers have been published on the detection and quantification of RUR soybean components in fresh or processed commodities based on specific protein and DNA detection. However, the detection and quantification of the RUR soybean component in Tempe has not been investigated so far. Tempe is a traditional Indonesian food made from fermented soybean that is consumed widely as well in other countries including USA, Europe and Japan, The processing to prepare Tempe consists of several pretreatment steps and a fermentation step. The pretreatment steps are soaking, dehulling and boiling. The fermentation is started by adding an inoculum of the fungus Rhizopus sp. During fermentation for 36 to 48 hours, the soybean seeds become inter connected and covered by mycelia of the fungus that gradually form a solid white cake of Tempe. The main objective of the research presented in this dissertation is to evaluate the protein and DNA based methods to detect and quantify the RUR soybean material in Tempe. The protein based methods used are Lateral Flow Strip test kits and an Enzyme Linked Immunosorbent Assay (ELISA) plate test kit design to detect RUR antigen in the material to be tested. The DNA based method used is a polymerase chain reaction (PCR) technique design to detect the presence of RUR-DNA. The international GMO standard for soybean consists of 6 samples of ground soybean which contain different percentages of RUR soybean. These materials have been used in this research for a positive control of known percentage (0, 0.1, 0.5, 1, 2, and 5%) of RUR soybean, Tempe was prepared from 100% of RUR soybean and from 100% of natural non-RUR soybean separately. Then mixtures of the two Tempe preparations were made. Both the Lateral Flow Strip and PCR test system did detect the presence of RUR soybean in local soybean sold by six out of seven companies in Bangkok. The Lateral Flow Strip test failed to detect RUR soybean in boiled soybean and Tempe produced from RUR soybean. In contrast, the PCR could still amplify and detect the RUR soybean DNA in boiled soybean and fresh Tempe. The ELISA plate test kit has been used to detect and quantify the RUR soybean antigen. The ELISA plate test kit can be used to quantify the percentage of RUR soybean in ground soybean and boiled soybean. But the ELISA plate test kit can not be used to quantify the percentage of RUR soybean in Tempe since the Tempe made from natural non-RUR soybean surprisingly give a false positive signal of RUR soybean. Apparently, the RUR antigenic material is produced during fermentation of natural soybean. PCR ELISA (DIG detection) can be used to detect RUR soybean in ground, boiled and Tempe. This technique can also be used to determine semi-quantitatively the percentage of the RUR soybean in ground soybean, boiled soybean and Tempe. However the calibrating values of each type of product differ significantly. In summary, this dissertation focused on the detection of GMO in ground and Tempe using protein and DNA based methods. GMO can be detected (and quantified) depending on the specific features of the test used. The knowledge and observation will contribute to the right interpretation of GMO test results. Based on this study, it is recommended to base GMO food labeling on PCR methods. All GMO quantification systems for processed food have to be calibrated using appropriate standard materials. The protein based test systems have proven to be very valuable in the field, but have less impact. For ground soybean and corn, a series of international standard is available to be used in various phases of the processing. Further research will be needed to design protocols for GMO quantification that can be interpreted directly. PCR based methods are in this respect the best candidate. The false positive detection of GMO material in Tempe by the ELISA Plate test is a strong signal to agencies responsible for GMO detection to verify the data on GMO by independent tests. At the same time it shows to people concerned about long term effects of GMO production and processing, that GMO features including new antigenic sites can be generated spontaneously and can be a fact life in unstirred Nature. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. BP-03-02 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Stevens, Willem F.; |
| Examination Committee(s) | Suwalee Chandkrachang;Sunee Nitisinprasert;Mair, Graham;Yi, Yang;Zimmermann, Willi;Hock, Bertold; |
| Scholarship Donor(s) | LPIU-DUE Batch II, Soedirman University, Indonesia; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2003 |