Frying potato rings rather than straight strips produces fries with less oil, lower levels of acrylamide, less salt, and better taste, says a new study from the US.
“Our findings provide justification for a partial replacement of French fries with ring fries. Not only are ring fries healthier and tastier than conventional French fries, but they also have a new and unexpected shape that may be perceived as desirable,” wrote the researchers.
“By carefully sorting and processing optimally sized tubers, the production cost for ring fries can approach that of French fries.”
The study was performed by scientists from US food manufacturer the J. R. Simplot Company. The company is one of the largest privately held firms in the US, with annual sales reportedly of about $4.5 billion.
Led by Caius Rommens, the researchers also note that there would be an added economic incentive for food manufacturers.
“It can be most effective to produce ring fries in a processing plant that is also designed to make French fries,” they stated. “For example, a conventional sorting system can be used to segregate the 20 per cent of tubers that have an optimal diameter of 7.6 cm for ring fry production in an independent production line. In that case, recovery rates would be up to 70 per cent.”From the abstract
Linear strips from the inner core of tubers were compared to those from outer tissues, both before and after processing, and strips from either specific tissues or whole peeled tubers were also evaluated against ring-shaped cuts. Both strips and rings had 0.7 cm sides and, in most cases, a volume of 4.9 cm3.
They were analyzed for moisture content, antioxidants, asparagine, and reducing sugars. The material was then blanched, dipped in 0.5% disodium acid pyrophosphate and 0.3% glucose, dried at 77 °C, par-fried in soybean oil at 191 °C, and finish-fried at 168 °C.
The fried product was analyzed for sensory characteristics and oil, salt, and acrylamide content.
Results showed that strips from the inner core absorbed 28% more oil and exhibited inferior sensory characteristics compared to strips from the outer parts.
The extended drying and frying times needed to match the crispness and flavor of inner strips to those of regularly fried outer strips resulted in a further increased absorption of oil and, importantly, triggered a 163% increase in levels of the toxic Maillard reaction product acrylamide.
Potato rings consisted of higher dry matter material, contained more antioxidants, and had a lower surface-to-volume ratio than the conventional linear strips. Upon processing, they also absorbed 22% less oil, contained 26% less salt, and displayed superior sensory properties.
Thus, ring fries may represent an attractive alternative to French fries as processed staple food.Link to abstract and publication in Journal of Food Science