November 10, 2022

Nigerian scientist fortifies ‘Zobo’ to address iron deficiency in Africa

Nigerian scientist fortifies ‘Zobo’ to address iron deficiency in Africa

By Sola Ogundipe

A Nigerian scientist, Folake Oyewole, is developing an iron-fortified hibiscus-based drink popularly known as Zobo in Nigeria, which could help women with iron deficiency in Sub-Saharan Africa.

Oyewole, a chemical engineering PhD candidate in the University of Toronto’s Faculty of Applied Science & Engineering, is conducting research as her doctoral thesis project inspired, in part, by the potential health benefits of a refreshing drink.

According to the University of Toronto, Canada, the pioneering research, supported by the Schlumberger Foundation’s Faculty for the Future Fellowship, is targeted at addressing the menace of iron deficiency, the leading cause of anemia worldwide.

The new iron-fortified beverage is expected to make use of hibiscus sourced from Nigeria. 

 In women of reproductive age, iron-deficiency anemia can lead to poor health outcomes and pregnancy complications such as preeclampsia, postpartum infection and low infant birth weight.

In Nigeria, the World Health Organisation estimates that 55 per cent of women of reproductive age are anemic.

“People consume Zobo as a cold beverage in Nigeria because it’s refreshing and claimed to provide many health benefits.

“I wanted to ascertain whether these drinks actually add micronutrients to the body, and if they didn’t, whether we could make it so that they did in a way that could be absorbed and used by the body,” Oyewole explained.

The researcher has always been interested in the value-added processing of food and beverages, particularly ones with ingredients sourced from Nigeria.

Her passion led her to join the lab of Levente Diosady, a professor emeritus in the department of chemical engineering and applied chemistry, who specializes in food engineering. 

Diosady’s lab group is developing a new way to fortify beverages like Zobo with iron – a mineral that many across Sub-Saharan Africa, particularly women, are lacking in sufficient quantities. The new iron-fortified beverage will make use of hibiscus sourced from Nigeria. 

Fortifying foods with iron has been a key focus of Diosady’s Food Engineering Laboratory for years. Past projects have included a double-fortified salt, which in trials of 60 million consumers in India was found to significantly improve the iron status of women. 

 Diosady says, “Folake’s work continues our goal of improving the iron status of women and infants by providing a natural fortification of a locally produced beverage. If properly marketed, this fortified beverage could improve the iron status of women of reproductive age, without medical infrastructure or any change in dietary habits.”

Creating an iron-fortified beverage isn’t as simple as adding some mineral salts into the recipe. Oyewole’s new product needs to account for the unique challenges associated with the dietary habits of the population she is working with. 

The human body absorbs iron from well-rounded diets that include meats, eggs and leafy greens, as well as foods fortified with iron. But in Sub-Saharan Africa, many households are limited to eating mostly plant-based diets with very little variation due to the prohibitive cost of iron-rich meat. 

On top of this, many plants have an abundance of polyphenols. This family of naturally occurring molecules – which includes flavonoids, phenolic acids, and resveratrol – has many disease-fighting properties, including inhibiting cancerous tumor generation and growth. But polyphenols also bind to iron in a way that prevents the latter from being absorbed by the body.

Oyewole’s fortified hibiscus beverage needs to address both the inadequate dietary iron intake, as well as the reduced iron uptake that results from a diet rich in polyphenols.

“The most at-risk groups who are dependent on plant-based diets often don’t realize that they can’t absorb iron efficiently.

“This is why when addressing micronutrient deficiencies at the population level through food fortification, it’s really important to choose the right food vehicle.

“We want to reach this population with something they are familiar with, something they already produce and consume widely so we can predict the consumption pattern of the population,” Oyewole notes. 

She argues that it’s also important to choose a food that can be centrally processed so that the iron dosage can be controlled. And the fortification process shouldn’t be so expensive that it significantly raises the cost of the food. 

Oyewole began her research by analyzing the iron content of the hibiscus calyces – the part of the plant that protects the bud and supports blooming petals – used to make Zobo.

While Oyewole found it to be relatively rich in iron, 70 per cent is lost during the extraction process since most of the iron is bound to the residue that is not transferred into the beverage. She also found that calyces contain 25 times more polyphenols than they do iron. 

She then fortified the beverage by adding ferrous sulphate heptahydrate, an iron salt, to top up the iron already present. Her goal was to provide a total of six milligrams of iron per 250 milligrams – 30 per cent of the target recommended daily allowance for women of childbearing age. 

To prevent the iron-polyphenol interaction, she introduced disodium EDTA into the beverage. Previous results in the lab suggest that this substance can release iron from the iron-polyphenol complex and make it available to be absorbed by the body. 

Oyewole is also working on ensuring that her iron fortification method will preserve the organoleptic properties of the original beverage – that is, the flavour, texture, and colour. 

“Iron has a very distinct, metallic taste, so another layer of my work is to make sure that the sensory properties of the fortified beverage – the taste, mouthfeel, aftertaste, and colour – match the original. Otherwise, we risk formulating a fortified beverage that will be rejected by the consumer.” 

Once this is achieved, the next step will be to form partnerships with stakeholders, including government agencies in Sub-Saharan Africa, to make the fortified beverage accessible for the target population. 

Further, she notes, “Working in the Food Engineering Laboratory has been a great privilege.  From an outside perspective, it may seem like we just add micronutrients to food and that’s it. But there are a lot of complexities with the materials we are dealing with, including preventing unwanted interactions between the food vehicle and the added micronutrients.

“Our research outcome has the potential for significant impact globally. Invariably it challenges poverty, increases productivity, and promotes health – it is all intertwined.”