Globally, approximately 2 billion individuals experience iron deficiency, which can result in anemia, hindered brain development in children, and elevated infant mortality rates.
To address this issue, researchers at MIT have devised an innovative method to enrich foods and drinks with iron, utilizing tiny crystalline particles. These particles, referred to as metal-organic frameworks, could be sprinkled on dishes, added to staple foods like bread, or included in beverages such as coffee and tea.
“We are developing a solution that can be effortlessly integrated into staple foods across various regions,” states Ana Jaklenec, a primary investigator at MIT’s Koch Institute for Integrative Cancer Research. “What is considered a staple in Senegal differs from that in India or the U.S., so our objective was to create something that does not interact with the food itself. Consequently, we avoid the need to reformulate for every locale — it can be blended into a broad spectrum of foods and drinks without compromise.”
The particles formulated in this research can also transport iodine, another essential nutrient. Additionally, the particles can be modified to carry vital minerals such as zinc, calcium, or magnesium.
“We are incredibly enthusiastic about this new strategy and what we believe to be a pioneering application of metal-organic frameworks to potentially enhance nutrition, especially in developing regions,” remarks Robert Langer, the David H. Koch Institute Professor at MIT and a member of the Koch Institute.
Jaklenec and Langer are the senior authors of the research, which appears today in the journal Matter. MIT postdoctoral fellow Xin Yang and Linzixuan (Rhoda) Zhang PhD ’24 are the lead authors.
Iron Stabilization
Food fortification can effectively address nutrient shortages, but this method is often complicated because many nutrients are delicate and can decompose during storage or cooking. When iron is integrated into foods, it may interact with other substances in the food, imparting a metallic flavor.
In prior research, Jaklenec’s lab demonstrated that enclosing nutrients in polymers can shield them from degradation or interaction with other compounds. In a small clinical trial, the researchers discovered that women who consumed bread fortified with encapsulated iron were able to absorb the iron from the food.
However, a limitation to this approach is that the polymer contributes substantial bulk to the material, restricting the quantity of iron or additional nutrients that can be incorporated into the food.
“Encasing iron in polymers significantly boosts its stability and reactivity, facilitating its addition to food,” Jaklenec states. “However, for efficiency, it necessitates a considerable amount of polymer. This constrains the amount of iron you can deliver in a standard serving, complicating the achievement of daily nutritional objectives solely through fortified foods.”
In response to this challenge, Yang proposed a novel idea: Rather than enclosing iron in a polymer, they could utilize iron itself as a fundamental component for a crystalline particle known as a metal-organic framework, or MOF (pronounced “moff”).
MOFs comprise metal atoms connected by organic compounds known as ligands to form a rigid, cage-like framework. Depending on the selected metals and ligands, they can be utilized for an extensive range of applications.
“We considered the possibility of synthesizing a metal-organic framework with food-grade ligands and food-grade micronutrients,” Yang explains. “Metal-organic frameworks possess very high porosity, allowing them to carry substantial amounts of cargo. That’s why we believed we could leverage this structure to create a novel metal-organic framework for the food sector.”
In this instance, the researchers designed a MOF consisting of iron bonded to a ligand called fumaric acid, frequently utilized as a food additive to enhance flavor or aid in food preservation.
This configuration prevents iron from reacting with polyphenols — compounds typically found in foods such as whole grains and nuts, as well as in coffee and tea. When iron reacts with these compounds, it generates a metal polyphenol complex that cannot be absorbed by the organism.
The MOFs’ structure also enables them to remain stable until they encounter an acidic environment, such as in the stomach, where they decompose and release their iron load.
Double-Fortified Salts
The researchers also chose to incorporate iodine into their MOF particle, dubbed NuMOF. Iodized salt has been extremely effective at thwarting iodine deficiency, and many initiatives are currently in progress to create “double-fortified salts” that would also include iron.
Simultaneously delivering these nutrients has proven challenging because iron and iodine can react with one another, reducing the likelihood of each being absorbed by the body. In this study, the MIT team demonstrated that once they formed their iron-containing MOF particles, they could infuse them with iodine in a manner that prevents interaction between iron and iodine.
In stability assessments of the particles, the researchers found that the NuMOFs could endure long-term storage, high temperatures and humidity, as well as boiling water.
Throughout these assessments, the particles preserved their structure. When the researchers subsequently administered the particles to mice, they determined that both iron and iodine became accessible in the bloodstream within several hours following NuMOF consumption.
The researchers are currently working on establishing a company focused on developing coffee and other beverages enhanced with iron and iodine. They also aspire to continue advancing toward a double-fortified salt that could be consumed independently or integrated into staple food products.
The research received partial support from J-WAFS Fellowships for Water and Food Solutions.
Other contributors to the paper include Fangzheng Chen, Wenhao Gao, Zhiling Zheng, Tian Wang, Erika Yan Wang, Behnaz Eshaghi, and Sydney MacDonald.