A group of Bangladesh Agricultural University (BAU) researchers recently discovered edible food colour in a type of soil fungus.
The fungus, Aspergillus niger, is found in red soil that can produce yellowish dye for food.
A research paper titled "Isolation and Identification of Natural Colorant Producing Soil-Borne Aspergillus niger from Bangladesh and Extraction of the Pigment" was recently published in the international journal MDPI, or the Multidisciplinary Digital Publishing Institute.
Led by Dr Md Abdul Alim, professor, Department of Food Technology and Rural Industries of the university, Professor Dr KHM Hussain Nazir and Assistant Professor Maria Afroz Toma were two key conductors of the research, assisted by other faculty members of the same department.
Professor Alim said "We have been trying to extract food grade colour from natural sources for a long time because there are many complaints about the artificial colouring that is currently used in food. There is also a lot of evidence of fabric colour being used in food, which is dangerous to health. That is why we were looking for a secure source of edible colour."
The research took six months to complete. Initially, red soil was collected from several places in Madhupur Upazila. The Aspergillus niger fungus was then isolated from the soil and the genetic characteristics of the fungus were tested.
In the next step, the fungus was used to prepare different foods and a significant change in the food colour was visible. In the last step, the food was fed to laboratory rats in different amounts and the rats were kept under close observation. The research showed that the food did not have any harmful effects on the rats.
Professor Alim hopes that the food dye will be commercialised in the future so that people have access to safe and healthy food colouring.
Another researcher in the project, Dr KHM Nazmul Hussain Nazir, said many other fungi can produce a variety of edible colours.
About the cost of the edible dye extracted from Aspergillus niger, Professor Nazir said the cost can only be determined once the colour is produced on a commercial scale.
More research on the issue is necessary for which funding is essential, he added.