West African Dish Inspires New Corrosion Study
A study examining the presence of metals in fufu, a common meal staple in West Africa, recently led to the investigation of corrosion in cookware and the affects of road salt on metal.
The work was recently conducted by Western University (London, Ontario, Canada) chemistry Ph.D. candidate Robert Addai in the university’s Material Science Additions lab.
Fufu is traditionally made from pounding cassava, a tropical root vegetable. While the process used to take hours, most people reportedly now use a metal “fufu pounding machine,” that offers the repetitive pounding action in a hands-free form.
“It is a delicious food, but it takes a lot of time. The machines also work in the form of friction, by pounding. My research is focused on whether metals are released from the machine into the fufu,” Addai said.
“Our question is, where is the wear and tear in the machine, and is it impacting the fufu? When people eat this, what is the effect? We have to find a way of seeing how much metal is in the food.”
To examine this, Addai measured the chromium, iron, manganese and nickel present in samples of fufu, using a slurry of the food with two types of carefully cleaned stainless steel.
Chemistry PhD candidate Robert Addai started by studying fufu, a staple of his Ghanaian diet.— Western University (@WesternU) May 23, 2023
But his research on corrosion in #WesternU Material Science lab led him to a field of study far from a West African kitchen: an icy Canadian road. https://t.co/niCkKBpV1p @westernuchem
The food was reportedly broken down in a digester before Addai analyzed the final solution for trace amounts of metals with a specialized tool for quantifying ions. After reviewing the results, the university says Addai found the highest concentrations to be iron, followed by manganese, chromium and nickel.
Addai also made fufu in several ways, with one sample made from cassava flower and homemade samples of “traditional fufu” made by machine. The samples were reportedly tested after 30 minutes, 24 hours and one week, due to the various lengths of time fufu can be cooked for.
According to the release, Addai found that the release of metals increased with time and, in some samples, there were potentially harmful levels of nickel and chromium.
“There are a lot of people, not only in Ghana, but all over the world, especially in the diaspora who are suffering from cancer, heart disease and other illness. Scientifically, we don’t always know the cause. So I wanted to study this (food preparation) from the start to check if some of the diseases are coming from this food,” Addai said.
Looking at cookware specifically, stainless steel is the most widely used material and is commonly found as either grades ASTM 201 or ASTM 304. Subsequent light microscopy and scanning electron microscopy (SEM) revealed localized corrosion on the surface of the stainless steel, indicating localized breakdown of the stainless steel’s passive oxide layer.
Western University reports that this initial study led the researcher to look at metal corrosion on icy Canadian roads, using different brands of road salt used for melting and grip on the roadways.
Last winter, Addai began tests by placing the same stainless steel used for the fufu experiment in the parking lot of Western Research Parks. The metal was reportedly left out for a two-month period and monitored while it was sprayed weekly with nine different kinds of road salt.
Addai and other researchers plan to continue this research next winter, including testing road salts used by Western’s facilities management team.
“We hope to recommend the best product, to balance effectiveness with environmental impact,” Addai said, adding that waiting for results of each test can sometimes be a tedious process as there are usually multiple stages and phases.
Addai states that he is travelling home to Ghana soon and said he can’t wait to enjoy the fufu made by his loved ones, instead of the version he makes in Canada using cassava flour. “I told my family, have the fufu ready,” he said. “It’s the first thing I want to do. I miss it so much.”