The humble cockroach could provide the superfood of the future.
An international group of scientists has discovered that the “milk” produced by a species of cockroach has great nutritional value and could become a food supplement for human consumption.
"It is quite niche," said Maria O'Sullivan, associate professor in human nutrition at the Trinity Centre for Health Science.
“The source alone would be interesting, even in marketing a synthetic version.”
The substance produced by the cockroach is not strictly milk as we know it, but it is provided for offspring developing inside the insect.
It is produced as a liquid, but becomes a crystal inside the developing cockroach’s gut.
Cockroach “milk” crystals have four times the amount of energy as an equal amount of cow’s milk.
"The crystals are like a complete food - they have proteins, fats and sugars," said Dr Sanchari Banerjee, the leading author of the study, in an interview with the Times of India.
The crystals are also loaded with essential amino acids and release nutrients gradually as they are being digested.
"It's time-released food," said Prof Subramanian Ramaswamy, professor of biochemistry at the University of Iowa and senior author of the work.
“If you need food that is calorifically high, that is time-released and . . . complete, this is it.”
The practicalities of milking cockroaches could hamper the potential value of the crystals.
However, researchers hope that now that they know what the crystals are made of, they will be able to produce them synthetically.
Development
Most cockroaches lay eggs, but the Diploptera punctata species carries its young inside the mother.
Here, the infants are fed by the mother with a liquid formed in the cockroach equivalent of a womb.
Once inside the developing cockroach’s gut, the “milk” develops into crystals.
Substances in the guise of crystals are not unusual in nature, as compounds such as insulin can be generated in a crystalline form.
This makes them more stable and facilitates their longer-term storage.
The cockroach milk crystals have this desirable property.
“They’re very stable. They can be a fantastic protein supplement,” said Mr Ramaswamy.
Vanesa Martinez is on placement at The Irish Times under the BSA/SFI media fellowship programme