Beetle larvae, like mealybugs, are often considered creepy, crawly pests. But these insects are edible and can be a healthy alternative to traditional meat protein sources. Today, researchers report that they have created a “meat-like” flavor by cooking insects with sugar. It may someday be used in convenience foods as a tasty source of additional protein.
The researchers will present their results today at the fall meeting of the American Chemical Society (ACS).
“Recently, eating insects has become a topic of interest due to the rising cost of animal protein as well as the associated environmental issues,” says In Hae Cho, Ph.D., the project’s principal investigator.
According to the United Nations, the world’s population is estimated to reach 9.7 billion by 2050 and 11 billion by 2100. And all of them require large amounts of food, water and land resources to feed animal meat – especially cows, pigs and sheep. Additionally, cows are a substantial contributor to climate change, releasing copious amounts of methane in their burps. Therefore, a more sustainable source of protein is needed.
“Insects are a nutritious and healthy food source with high amounts of fatty acids, vitamins, minerals, fiber and high-quality protein, similar to meat,” says Cho, whose team is based at Wonkwang University (South Korea).
But edible insects suffer from an image problem, she says.
In many parts of the world, eating insects is not common, and people may complain about eating them. Some companies are trying to change people’s minds by selling cooked whole mealworms as chewy, salty snacks, but consumer acceptance is not widespread. Cho says that for more people to eat insects on a regular basis, a sneakier approach may be in order — hiding the insects as seasonings in easily cooked and other convenience products.
The research team’s first step was to understand the flavor profile of this insect. They compared the smell of food throughout its life cycle, from egg to larva to pupa to adult. While there were some differences in individual compounds, all phases consisted primarily of volatile hydrocarbons, which evaporate and give off aroma. For example, raw larvae smelled like wet mud, shrimp-like, and sweet corn.
Then Hojun Seo, a graduate student on Cho’s team, compared the flavors of the larvae that had developed as they were cooked in different ways. Steamed mealworms developed a stronger sweet corn-like aroma, while roasted and deep-fried versions had shrimp-like and fried oil-like qualities. According to Seo, the flavor compounds from roasting and frying included pyrazines, alcohols and aldehydes and were similar to compounds produced by cooking meat and seafood.
Based on these results, the team hypothesized that heating the protein-rich mealworms with sugar could produce more reactive flavors. Reaction flavors, sometimes called process flavors, are produced when proteins and sugars are heated together and interact, for example, through Maillard, Strecker and caramelization reactions and through fatty acid oxidation, Cho says. The result is usually a suite of “meat-like” and delicious flavors.
Hyeong Park, a graduate student in Cho’s lab and a presenter at the meeting, tested different production conditions and ratios of powdered mealworms and sugar, producing multiple versions of the reaction flavors. He identified a total of 98 volatile compounds in the samples. The team then took the samples to a panel of volunteers to respond to the most favorable “meat-like” smell. “As a result of this study, 10 feedback flavors were customized based on consumer preferences,” says Park.
To the best of the researchers’ knowledge, this is the first time that edible insects have been used to produce desirable response flavors. They hope these results will contribute to the commercial development of meat-like and savory flavors and seasonings, and encourage the convenience food industry to include edible insects in their products, Cho says. The team’s next step is to further optimize the cooking processes to reduce any potentially undesirable or off-flavors in the final flavor material made from cooking worms.
The researchers acknowledge support from the Rural Development Administration (South Korea) and Wonkwang University (South Korea).