The researchers from the Institute of Stem Cell Biology and Regenerative Medicine, (InStem) in Bengaluru, India, believe the milk, produced by the Pacific beetle cockroach, could be used as a protein supplement in the future and are trying to find a way to produce the protein crystals in their lab.
More than three times the energy of buffalo milk
The discovery came after the team was looking at the structure of milk protein crystals in the gut of a roach species called Diploptera punctata, the only known viviparous cockroach (which gives birth to live young).
Subramanian Ramaswamy, co-author of the study, ‘Structure of a heterogeneous, glycosylated, lipid-bound, in vivo-grown protein crystal at atomic resolution from the viviparous cockroach Diploptera punctata’, InStem, said a single crystal contains approximately more than three times the energy of an equivalent mass of dairy (buffalo) milk.
“The cockroach secretes a type of milk that contains protein crystals to feed its embryos before they are born. These crystals, in turn, contain protein and essential fats, sugars and amino acids,” he said.
“The protein also has other benefits, like the fact that it releases energy slowly over a long period of time. It's time-released food.”
“If you need food that is calorifically high, that is time released and food that is complete. This is it.”
Not ready to sell in the market
Ramaswamy told DairyReporter it was an accidental observation of cockroach embryos that later turned out to be crystals.
“Investigating this out of curiosity revealed that these crystals are made of highly nutritious proteins,” he said.
However, researchers did not set out to find food substitutes.
“I do not see cockroach milk being isolated from cockroach and being sold [as a commodity]. They will be made using modern biotech tools in a fermenter,” he added.
Moving forward with the research, Ramaswamy said the team will see if they can first duplicate those protein crystals in yeast using biotechnology, and understand how it crystallizes readily.
“Once we can make them in significant quantities, we’ll test them for safety,” he said.
The study findings are found in the International Union of Crystallography Journal this month.
The other scientists involved in the project are affiliated to the National Centre for Advancing Translational Sciences, National Institutes of Health in the US, Structural Biology Research Centre, High Energy Accelerator Research Organisation in Japan, Centre for Cellular and Molecular Platforms (C-CAMP) in India, Department of Cell and Systems Biology, University of Toronto in Canada, University of Iowa in the US and Experimental Division, Synchrotron SOLEIL in France.