Sorghum: Health food, sweetener, now clothing dye

Sorghum has long been a staple food in many parts of the world, but in the United States, it is best known as a sweetener and livestock feed.

As demand for the grain soars, so does the amount of waste husks. To reduce this waste, scientists from the University of Nebraska-Lincoln, and Drs. Yiqi Yang, Xiuliang Hou, and colleagues from Jiangnan University-China, wanted to see if they could develop a practical clothing dye out of sorghum husks. Their research was reported in the journal American Chemical Society or ACS Sustainable Chemistry and Engineering as a new use for the husks: A wool dye that can add ultraviolet or UV protection and fluorescence properties to clothing.

Sorghum, which looks like couscous, is a hardy, drought-tolerant crop that is gaining popularity as a health food, livestock feed and source of bioethanol. Scientists are also working on transforming the crop’s waste for a range of applications, including food coloring and waste water purification. Building further on the colorant possibilities, the researchers at Jiangnan University wanted to see if they could develop a practical clothing dye out of sorghum husks.

The researchers tested extracts of husks on wool materials, which turned varying shades of brown. The dyes showed good colorfastness even when the wool was washed, rubbed, and ironed. They also added UV protection and fluorescence properties to the materials, which withstood 30 cycles of laundering.

This project is funded by the Special Fund for the Transformation of Scientific and Technological Achievements in Jiangsu Province, the Science and Technology Guidance Project by China Textile Industry Association, the Fundamental Research Funds for the Central Universities,

The project was funded in part by the NIFA’s Multistate Research Fund and the Agricultural Research Division at the University of Nebraska-Lincoln.