Dr Daylan Tzompa-Sosa, a researcher at the University of Wageningen in the Netherlands, said the fashion for protein research had blinded the scientific community to an important prospect within edible insects: fats and oil.
Tzompa-Sosa said she had seen the opportunity when her colleagues were working on a protein project funded by the Dutch government. Her fellow researchers were discarding the oil as they isolated the protein.
Insects have fallen into the spotlight in recent years as a possible solution to increasing pressures on global food supplies fueled by a growing global population.
But it’s not just protein sources that put pressure on resources and the environment, oils like soy, sunflower and palm also take up great swathes of land to produce oil.
"It is important to know there are other sources that are just as good," Tzompa-Sosa said. "There are some companies in the Netherlands that are starting to be serious about the extraction of proteins [from insects], so if this happens then the oil will be a by product and then, well, we better use it."
As part of an ongoing spinoff project of the FAO-funded research, she was testing the properties of oils from various insects including the flour maggot, beetle larvae, cockroach and cricket.
But can she envisage consumers choosing cockroach oil over olive oil?
Globally, the most commonly consumed insects are beetles (31%), caterpillars (18%) and bees, wasps and ants (14%).
This was followed by grasshoppers, locusts and crickets (13%), cicadas, leafhoppers, planthoppers, scale insects and true bugs (10%), termites (3%), dragonflies (3%), flies (2%) and others (5%).
Chewing the fat
Not all insects would be suitable for edible oils. Cockroach oil smelt “especially disgusting” and something like vomit, she said.
“This oil would never be intended for human consumption, also because of the perception. It might be easy to market cricket oil, for example, but there is no way you could market a cockroach oil I would say just because of the idea of it.”
Cockroaches are notoriously resistant and breed quickly, which could be harnessed for other purposes. Oils not suitable for food, like cockroach oil, could still be used as an industrial lubricant or in paint.
Meanwhile the grasshopper and the soldier fly was said to have a fruity, pleasant aroma.
Insect fats are already used traditionally in some parts of the world to fry meats and as a hair and skin product.
According to an FAO report, insects are part of the traditional diets of at least two billion people with over 1,900 species reportedly used as food.
Animal, vegetable or mineral?
Insect oil was something like a half-way house between vegetable and animal fat.
It was neither as saturated as animal fat nor cholesterol-free like vegetable oil.
Whilst not comparable to omega-3 levels from fish, Tzompa-Sosa’s research has shown insect oils contained essential fatty acids oleic acid, linoleic acid and linolenic acid.
In the four insect species studied, the average amount of unsaturated fatty acid ranged from 64 g/100 g in beetles (A. diaperinus) and crickets (A. domesticus) to 75 g/100 g in mealworms (T. molitor) and cockroaches (B. dubia).
The lipid content of insects ranged from less than 10% to over 30% of fresh weight basis depending on the insect.