Four years ago, a team of MIT Sloan professors won $600,000 in grants to support their research projects on global food and water security. The team — which includes Retsef Levi, Tauhid Zaman, Yasheng Huang, Stacy Springs, and Karen Zheng — has received significant funding to further support their research. They've also started a collaboration with the Walmart Foundation in China to study global food supply chains and the regulatory landscape.
The team’s research paper on supply chain dispersion and its relationship to the risks of food manufacturers has been accepted for publication at Management Science. They are also actively collaborating with public and private organizations in the field to research ways of improving farmer and consumer welfare in agricultural supply chains and markets in developing countries.
Agricultural supply chains and their associated risks are a broad topic, and one that can be confusing if you’re working in that space. We asked Zheng, an MIT Sloan associate professor of operations management, to lay out the basics.
Zheng said there are no strict boundaries for food adulteration — generally defined as when a food item’s quality is lowered by accident or on purpose. It’s a sliding scale depending on the motivation and what’s been added or substituted or what corner has been cut. Except, Zheng said, in the case of terrorism, when intentional human harm is the main reason for tainting a food supply.
Zheng said unintentional adulteration is the result of "negligence, ignorance, or lack of knowledge."
For example, someplace doesn't know they have to keep raw fish below a certain temperature to avoid bacterial growth. It’s not for economic gain — it won’t help your bottom line if no one wants to buy your rotten fish — but more a result of carelessness when handling food, or from something in the surrounding environment.
Remember the romaine lettuce recall of the 2018 holiday season? Santa Maria, California-based Adam Bros. Family Farms issued a warning to customers to throw out lettuce and cauliflower after the company discovered dirt from a nearby reservoir tested positive for E. coli. More than 50 people across the country got sick from eating the vegetables.
Similarly, there was another E. coli outbreak in Yuma, Arizona in the spring of 2018, which sickened 200 people and killed 5. In that case, federal officials pointed to a nearby cattle feed yard as the potential culprit for contaminated water used on the crops.
This kind of adulteration is done for economic gains. Someone along the food supply chain wants to increase their income, and so they cut corners or add or substitute something to their product so they can make more money.
“Our focus is on economically motivated adulterations that can cause harm to human health because these pose the greatest threats to the society,” Zheng said. “There are also intentional adulterations with limited health implications."
Replacing honey with high-fructose corn syrup, for example, or using donkey or horse meat in lieu of beef will not necessarily hurt anyone, Zheng said.
Zheng’s focus is on economically motivated adulteration like overusing antibiotics on livestock, or in the case of the 2008 Chinese baby formula scandal, farmers or milking stations added melamine [a chemical used for making plastic] to milk to falsely boost protein levels.
“That’s why there’s blurred boundaries,” Zheng said. “They were not adding melamine in to kill people [although it resulted in 6 infant deaths and tens of thousands of babies and children sickened], they were adding it in to increase the protein content so they could sell the milk at a better price. They were trying to raise their income.”