Food scientists from the National University of Singapore (NUS) developed a rapid and highly sensitive screening technique capable of detecting minute amounts of pesticides in vegetables.
The innovative strategy reduces the screening process to under two hours, according to a press release by NUS on Feb 20, 2018.
Synthetic pesticides such as pyrethorids are widely used in vegetable farming to control agricultural pests. While the use of these pesticides improves crop yield, long-term ingestion of excessive pesticide residues through the consumption of fruits and vegetables could lead to adverse health effects.
Current methods to screen crops for pyrethorid residues require time consuming and costly procedures, and can take up to six hours to process and analyse a sample.
To simplify the procedures, developed polystyrene coated magnetic nanoparticles which can effectively extract pyrethorid residue from vegetable crops for analysis via simple magnetic separation. The nanoparticles are first added into a liquid sample obtained from vegetables, serving as “micro magnets” to attract pyrethroid molecules. Pyrethroids bound on the nanoparticles are then washed off by a small amount of organic solvent and collected for analysis.
This innovation is led by Assistant Professor Yang Hongshun and his PhD student, Miss Yu Xi, both from the Food Science and Technology Programme at the NUS Faculty of Science.
“Existing screening methods require long processing time and hence it could be challenging to apply such methods to detect pesticide residue in a large batch of samples, which is vital to ensuring food safety. Our method therefore offers a faster and more effective alternative,” said Asst Prof Yang.
This novel screening technique can also be modified for different purposes and holds immense potential for the safety of the food industry. “With small modifications to the extraction process, this method can be used to detect pyrethroids in other food products such as nuts, fruits and vegetable oils. Modifications can also be made to the coating of the nanoparticles to detect other types of pesticides and chemicals including mycotoxins and antibiotics,” said Miss Yu.