In an attempt to study how the internal structures of foods change when they’re dunked in hot oil, researchers at University of Illinois have been using X-ray technology.
Using a new imaging technology called X-ray micro-computed tomography, also known as micro-CT, food scientist Pawan Takhar and his colleagues have been taking three-dimensional images of potato slices, fried for various lengths of time.
Takar explained that although conventional lab techniques allow us to see the amount of oil in a food, we “didn’t know how it gets distributed throughout the material.”
Regular X-rays can be taken as fast as 30 frames per second, and micro-CT scans are just as effective at capturing images. Takhar stated that 986 two-dimensional images of the potato samples were collected and combined to produce the 3D images.
Ultimately, researchers found that the longer the frying time, the larger the pore size in the types of food, which allowed for a greater intake of oil.
A correlation between oil content and the network of pathways between pores suggested that oil penetration into the food would be easier the longer it fried.
The oil content and the air pockets found in the pore structure provide the much desired crispy texture found in fried foods like chicken nuggets and potato chips, said the researchers.
One possible application of this study would be to make traditionally fried food healthier, so they have the same texture and taste but a lower fat content.
Takhar and his team still have a lot to learn about the frying process and its effect on food. Takhar and his lab have been studying the frying process for 10 years, but he said that “We still only understand about 10% of what is taking place during frying.”
