Screening of P-35S, P-FMV, and T-NOS genetic elements in microwave-treated genetically modified cereal flours.

BACKGROUND: Reliable and efficient methods for detecting genetically modified organisms (GMOs) in unprocessed and processed food will be essential for establishing an effective system for traceability all along the supply chain. It is important to understand the detection of GMOs following microwave treatment, which is a common processing method used in various food products such as flours. Therefore, this study aimed to detect the presence of Cauliflower mosaic virus (CaMV) 35S promoter (P-35S), Figwort mosaic virus (FMV) promoter (P-FMV), and T-NOS (nopaline synthase terminator) genetic elements in DNA samples from untreated and microwave-treated genetically modified (GM) cereal flour samples using the qualitative polymerase chain reaction (PCR) based screening method. METHODS AND RESULTS: DNA was extracted from all samples, and the efficiency of the qualitative PCR screening technique was tested by the verification studies. We performed an inhibition study with plant-specific actin (ACT) gene to the effectiveness of confirming the DNA extraction method. Then, we made the confirming of the qualitative PCR system by method performance testing criteria. The high quality and quantity of the DNA extracts from untreated and microwave-treated flour samples indicated the applicability of qualitative PCR screening assays. The results showed that microwave radiation does not significantly impact the genetic element screening in flour materials. CONCLUSION: Untreated and microwave-treated flour samples had amplifiable DNA for the simultaneous screening of three genetic elements. The qualitative screening tests conducted in this study produced dependable outcomes, thus, can be successfully used for monitoring in control laboratories.

Development of a peptide substrate for detection of sunn pest damage in wheat flour.

BACKGROUND: Since the common protease substrates did not give satisfactory results for the determination of Sunn pest protease activity in damaged wheat, different peptide substrates derived from the repeated sequences of high molecular weight glutenin subunits were synthesized. RESULTS: Hydrolysis of peptides by pest protease was determined by high-performance liquid chromatography. Among three peptides having the same consensus motifs, peptide1 (PGQGQQGYYPTSPQQ) showed the best catalytic efficiency. A novel assay was described for monitoring the enzymatic activity of protease extracted from damaged wheat flour. The selected peptide was labeled with a fluorophore (EDANS) and quencher (Dabcyl) to display fluorescence resonance energy transfer. The proteolytic activity was measured by the change in fluorescence intensity that occurred when the protease cleaved the peptide substrate. Furthermore, the assay developed was modified for rapid and easy detection of bug damage in flour. Flour samples were suspended in water and mixed with fluorescence peptide substrate. After centrifugation, the fluorescence intensities of the supernatants, which are proportional to the protease content of the flour, were determined. CONCLUSION: The total analysis time for the assay developed is estimated as 15 min. The assay developed permits a significant decrease in time and labor, offering sensitive detection of Sunn pest damage in wheat flour. © 2018 Society of Chemical Industry.