Why cooking a stir fry could be bad for health, according to scientists

A stir fry of pork and Chinese greens.

It may seem like a healthy option, but cooking a stir fry could be bad for health because it shoots microscopic particles of fat into the air, which could be hazardous if inhaled, scientists have warned.

Researchers at Texas Tech University and Utah State University heated up oil in a frying pan and then recorded what happened when droplets of water were added.

They found the results were "dramatic" with the water causing the fat to explode, sending tiny oil droplets into the air, which are "inhalable and potentially hazardous".

The scientists say foods like chicken, or Chinese stir fry, may be the worst culprits for spraying oil into the air because poultry and vegetables contain large quantities of water.

Dr Jeremy Marston, assistant professor at Texas Tech University, said: "We've discovered that a very large number of small oil droplets are released when even a single, small droplet of water comes into contact with hot oil.

"The resulting phenomena is dramatic - you can see the explosive release when the water, trapped under the oil, vaporises all of a sudden. This causes the oil film to rupture and sends oil droplets flying.

"Our research may be particularly relevant to Chinese cooking methods in which water is added to hot woks."

The scientists are now using high-speed video to record and calculate the size and distribution of oil droplets released and to see how far they can reach in a kitchen with, or without, ventilation.

"It's known that millions of deaths worldwide occur due to indoor air pollution, but we don't know yet how much cooking in poorly ventilated kitchens contributes to it," added Marston.

"We're planning to conduct a detailed study to quantify how much impact kitchen-based aerosols have on indoor air pollution.

"Ultimately, we hope that our research can guide designs for improved ventilation systems to remove these ultrafine aerosols."

The findings of the research were presented during the 70th annual meeting of the American Physical Society's Division of Fluid Dynamics in Denver, Colorado.