Development of nucleic acid isolation by non-silica-based nanoparticles and real-time PCR kit for edible vegetable oil traceability.

For efficient extraction of amplifiable DNA from edible vegetable oils, we developed a novel DNA extraction approach based on the non-silica-based dipolar nanocomposites. The nanoparticle comprises a hydrophilic polymethyl methacrylate core with abundant capillaries, hydrophilic vesicles decorated with molecules having DNA affinity and a coating hydrophobic polystyrene layer. The nanoparticles are soluble in oil, adsorb the DNA from the aqueous phase and gave a high DNA recovery ratio. All DNA extracts from fully refined vegetable oil soybean, peanut, rapeseed, and cottonseed oils, including their blends, were sufficiently pure to be amplified by real-time PCR targeting the chloroplast ribulose-1,5-bisphosphate gene (rbcL), therefore, the species of origin and their ratios in mixed vegetable oils blended from two or three oil-species could be determined. These results indicate that the novel DNA isolation and real-time PCR kit is a simple, sensitive and efficient tool for the species identification and traceability in refined vegetable oils.