Model Systems for Developing Detection Methods for Foods Deriving from Genetic Engineering

✍ Scribed by U. Konietzny; R. Greiner

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 73 KB
• Volume: 10
• Category: Article
• ISSN: 0889-1575
• DOI: 10.1006/jfca.1997.0521

✦ Synopsis

Model systems for investigating the influence of the food matrix and depth of processing on detection limits for foods deriving from genetic engineering were established using the phytaseencoding gene of Escherichia coli ATCC 33965. For detection the polymerase chain reaction was applied directly to DNA extracted from foods based on cereals. E. coli cells and E. coli DNA were added to musli, rolled oats, and rye flour in concentrations of 10 10 to 10 2 CFU and 10 mg to 10 pg per gram, respectively. After soaking of the food samples in water or yoghurt, detection limits were determined to be 10 3 to 10 4 CFU and 10 to 100 pg by specific DNA hybridization. After sourdough fermentation of rye flour a hybridization signal was observed only with rather high E. coli concentrations (ú10 10 CFU), whereas detection was impossible in ready-baked breads.