Comparative Studies of the Quantification of Genetically Modified Organisms in Foods Processed from Maize and Soy Using Trial Producing

Abstract

Seven types of processed foods, namely, cornstarch, cornmeal, corn puffs, corn chips, tofu, soy milk, and boiled beans, were trial produced from 1 and 5% (w/w) genetically modified (GM) mixed raw materials. In this report, insect resistant maize (MON810) and herbicide tolerant soy (Roundup Ready soy, 40-3-2) were used as representatives of GM maize and soy, respectively. Deoxyribonucleic acid (DNA) was extracted from the raw materials and the trial-produced processed food using two types of methods, i.e., the silica membrane method and the anion exchange method. The GM% values of these samples were quantified, and the significant differences between the raw materials and the trial-produced processed foods were statistically confirmed. There were some significant differences in the comparisons of all processed foods. However, our quantitative methods could be applied as a screening assay to tofu and soy milk because the differences in GM% between the trial-produced processed foods and their raw materials were lower than 13 and 23%, respectively. In addition, when quantitating with two primer pairs (SSIIb 3, 114 bp; SSIIb 4, 83 bp for maize and Le1n02, 118 bp; Le1n03, 89 bp for soy), which were targeted within the same taxon specific DNA sequence with different amplicon sizes, the ratios of the copy numbers of the two primer pairs (SSIIb 3/4 and Le1n02/03) decreased with time in a heat-treated processing model using an autoclave. In this report, we suggest that the degradation level of DNA in processed foods could be estimated from these ratios, and the probability of GM quantification could be experimentally predicted from the results of the trial producing.

Investigation of Residual DNAs in Sugar from Sugar Beet (Beta vulgaris L.)

“…Yield and quality of extracted DNA from in-process samples and beet sugar products DNA was extracted from 1 g of each in-process or beet sugar product sample with the anion exchange column, Genomic-tip 20/G (QIAGEN), which we have been using for the DNA extraction of highly processed foods 3) . The yield and quality of the extracted DNA solution was estimated from the UV absorption spectrum.…”

“…In Japan, the mandatory GM labeling is not required for processed foods that do not contain a su$cient amount and/or quality of marker DNAs or proteins, e.g. cooking oil and soy sauce῍ 3 . Based on the result of this investigation, the Japanese government has decided that the mandatory GM labeling is not applicable the sugar products.…”

Semiquantitative analysis of genetically modified maize and soybean in food

“…5´-ACCATCAACAGCCGCTACAACGACC-35´-TGGGGAACAGGCTCACGATGTCCAG-3´C ryIA(b) 71ºC 184 bp Transgene specific At present, quantitative detection in food has been performed only in some model systems (Yoshimura et al 2005a;Yoshimura et al 2005b). The aim of this work was to set up a protocol to semi quantify GMO in foods with different composition and processing degree.…”

Opinion of the Scientific Panel on genetically modified organisms [GMO] related to the safeguard clause invoked by Greece according to Article 23 of Directive 2001/18/EC and to Article 18 of Directive 2002/53/EC

“…Hernández et al (2003) describes a specific real-time quantitative PCR detection system for identifying the MON810 maize event. Subsequently, other event specific detection methods have been proposed by, for example, Germini et al (2004Germini et al ( , 2005, Huang and Pan (2004), Bordoni et al (2005), Onishi et al (2005), Yoshimura et al (2005), and Hernández et al (2005). Issues related to specific molecular detection methodologies as well as on their validation are not within the scope of the GMO Panel.…”