Development of a method to recovery and amplification DNA by real-time PCR from commercial vegetable oils

•High-quality DNA is essential for DNA-based food safety and traceability methods.•A CTAB-based method was optimized and amplifiable DNA yield was improved.•qPCR was used in the development and optimization of a DNA extraction method.•A rapid and economic DNA extraction method was successfully developed.•The method applicability was assayed in commercial vegetable oils and margarines. This study describes the design of a suitable DNA isolation method from commercial vegetable oils for the application of DNA markers for food safety and traceability. Firstly, a comparative study was made of eight methods for the recovery of high quality DNA from olive, sunflower and palm oils, and a CTAB-based method was selected. In order to optimize this method, the effect of the organic compounds and several components in the lysis buffer and the lysis and precipitation time were evaluated. For the purpose of overcoming the limitations detected in spectrophotometric and PCR DNA yield evaluations, the performance of the extraction protocols during the optimization processes was evaluated using qPCR. The suggested DNA extraction optimized is less time consuming than other conventional DNA extraction methods, uses a reduced oil volume and is cheaper than available commercial kits. Additionally, the applicability of this method has been successfully assayed in ten commercial vegetable oils and derivatives.