Research points to new ‘greener’ plant extraction method for red dye
The extract from red capsicum is being increasingly used as a colorant in a range of personal care products and color cosmetics to enhance their appearance, in place of synthetic red colorants that have been linked to cancer.
Until now the conventional method of extraction for the capsicum has relied on a solvent called hexane – a chemical process that can permeate the extract and has been linked to toxicity in some studies.
The chemical extraction industry has been looking at alternative methods of extraction for some years now, which is why scientists at New Mexico State University have been looking into alternative methods.
Green chemical extraction method
The research team, which is part of the university’s Department of Plant and Environmental Sciences, developed a ‘green chemical’ method of extraction that generates an oleoresin from dried Capsicum fruit.
Likewise, the method incorporates a process that separates the pigments from the capsaicinoids, which the researches say is an important step towards making the processing more flexible for pigment production.
The researchers claim that the resulting extraction has virtually the same carotene and xanthophyll composition as the extraction derived using the conventional method, based on hexane.
Increased production efficiencies
The method is also claimed to recover in excess of 85 percent of the pigmented carotenoids – a more efficient extraction method that helps to cut down on waste as well as the environmental risks that concern the conventional method.
In a report published in the American Society for Horticultural Science journal, HortScience, corresponding author for the study, Mary O’Connell stated:
“If alternative and environmentally sound ‘green’ extraction protocols could be developed to replace the use of hexane as a solvent for oleoresin production, this would improve the environment risks for the isolation of red pigments from Capsicum fruit.”
