Can you get red, blue and yellow from fungi? Researchers are developing environmentally friendly natural colourants

Natural dyes and pigments, or biocolourants, can be derived from plants, bacteria and industrial by-products, but this process is more expensive and difficult than producing artificial colourants. Researchers in the BioColour project are investigating how biocolourants could be produced to meet the needs of industry and consumers.

Up to the 19th century, everything from textiles to paints were dyed with biocolourants, but artificial colourants introduced by industrialisation replaced natural colourants derived from, among other things, plants or fungi. But in today’s world, could biocolourants compete with synthetic colourants, or even substitute for them to a certain degree? This is the topic investigated by the BioColour project, which was awarded a significant six-year funding grant by the Strategic Research Council of the Academy of Finland in summer 2019.

“We are looking into opportunities to produce large quantities of safe and ecologically sound biocolourants for industrial and consumer use. We are interested not only in plants, but also yeasts, algae and bacteria. Furthermore, colourants can be extracted from industrial by-products, such as the waste resulting from berry pressing,” says University Researcher Riikka Räisänen.

Räisänen, who is both a chemist and craft teacher by education, is heading the project at the Faculty of Educational Sciences, University of Helsinki.

Full palette

The researchers aim to utilise nature in producing the entire colour palette: blue, red, yellow, green, brown and black. Among other things, they are investigating which fungi would be suited to producing specific colours.

Even though very little research on biocolourants has been conducted in Finland, the work does not have to start from scratch, thanks to the variety of experiments underway elsewhere in the world. One of the outcomes of the project will be an open biocolourant database into which both the existing data and the data produced over the course of the project will be collected.

“For instance, we know that dyer’s woad (Isatis tinctoria), a rare plant in Finland, is effective for producing the colour blue,” Räisänen notes.

The project is guided by friendliness to the environment, which is evidenced in all its activities. New colourants are meticulously examined.

“The toxicity of colourants for both humans and the environment is determined without animal testing. Only the colourants found to be harmless will be investigated further. This work will be carried out at the University of Campinas, Brazil, and the University of Eastern Finland in Kuopio.”

Consumer attitudes to colourants derived from nature will also be surveyed.

“We will investigate how consumers accept and adopt biocolourants. For the time being, consumers’ knowledge of biocolourants is limited, but their environmentally friendly nature is sure to have an appeal in today’s world,” Räisänen states.

“We have a channel at our disposal through which we can influence future generations: craft and home economics teachers, both of whom are trained at this Faculty. This way, knowledge related to biocolourants can be disseminated to school classes and, further on, to consumers.”

Commercial use

Among the goals of the project is to produce colourants for packaging materials that are biodegradable and attractive to consumers.

“We have as partners businesses whose needs and expectations we are closely listening to,” Räisänen says.

So far, there are not many businesses in Finland that use biocolourants in their products. There are no mass producers, and only a handful of small businesses in the cosmetics industry and food industry utilise such colourants.

“The range of uses is endless. At the moment, producing biocolourants is more expensive than synthetic colourants, but we aim to innovate inexpensive ways of producing large quantities of safe and environmentally friendly colourants,” says Räisänen.

Also participating in the project is Aalto University’s textile design programme where ranges of clothes are designed, including clothing and accessories of varying colours dyed with dyer’s woad, among other colourants. The goal is to have a product series based on biocolourants available on the consumer market in six years.