“Slimy,” he reluctantly agrees, “yet satisfying.” He smiles.
Bugs are an increasingly common food source outside the cartoon jungle. Cricket flour has become particularly popular, with several companies using it to boost the nutritional content of pasta and protein bars, for example.
Now Dutch researchers are studying how another bug, the mealworm, can be turned into a source of solid and liquid fats to replace margarine or vegetable oils. Mealworms could make a good fat source because they’re relatively sustainable and easy to cultivate. These mealworm fats might make an appearance in European supermarket in the next few years, although it’s unlikely you’ll see them as shortening in your Oreos anytime soon. But let’s get the first question out of the way: What does mealworm oil taste like?
“We're not allowed to eat it because it's made in a lab,” said Daylan Tzompa-Sosa, a researcher at Wageningen University and Research Center. But the liquid product is a pleasant yellow, not unlike olive oil. “It smells very mild ... grassy. It's not bad," she said.
The team members created edible fats and oils through fractionation, meaning they heated a fat mixture and cooled it at a controlled rate in vats of 0, 2 and 4 degrees celsius water for a day. The temperature change allowed fat crystals to grow in the mixture, which the researchers separated into solids (or “stearin”) and liquids (or “olein”). They described their results in INFORM, the magazine of the American Oil Chemists’ Society, this past summer.
The solids and liquids have no trans fats, according to Tzompa-Sosa's research, and the solid mealworm fat is low in saturated fats – which is something consumers want, even if they'd rather leave insects out of it.
Alejandro Marangoni of the University of Guelph, who wasn't involved in the research, isn't quite convinced that mealworm margarine is the answer to our butter woes. Generally, saturated fats are solid, while unsaturated fats are liquid. “Structure is important,” he said. Tzompa-Sosa’s mealworm fats had about the same percentage of saturated and unsaturated fatty acid molecules whether they were solid or liquid, implying that the solid structure might come from the way the single chainlike fatty acids arrange themselves into triglycerides, a three-pronged molecule. “They really need a triglyceride analysis before we can judge this properly to figure out what is happening during fractionation,” he said.
Tzompa-Sosa agreed. “The fatty acid profile,” or the kinds of fat molecules in each “of our liquid and solid fats were very similar. That doesn't explain completely why we saw the differences. We need a chemical and physical analysis to explain why.”
Marangoni also noted that there weren’t a lot of the healthy omega-3 fatty acids in the mealworm mix. He thought the composition of the mealworm oil looked about the same as a 50 percent canola, 50 percent soybean oil mixture.
Plus, he wondered whether producers could scale mealworm oil to the levels of other oils. Malaysia exported 25 million tons of palm oil this year, according to the U.S. Department of Agriculture; just imagine how many mealworms it would take to make that much oil. “That’s a lot of worms,” he said.
Still, mealworms aren’t the first insect used as edible fat. European companies such as Protix use insect oil in animal feed, and Tzompa-Sosa’s team experimented with black soldier fly fat to make cupcakes. “We gave the cupcakes to 100 students and they couldn't tell a difference” between fly fat cupcakes and butterfat cupcakes, she said. She thinks environmentally conscious Europeans could start buying bug-based fats in the next few years. Whether consumer insect oil would fly depends on the country, though, and North and Latin America are different markets. Marangoni and I agreed that large vats of wriggling mealworms was an icky thought, no matter how you feel about consuming the benign-looking end product.
But, hey, I’d eat almost anything. Hakuna matata.