Efficient Extraction of Natural Dyes from Selected Plant Species

Eco-efficient and cost effective methods for extraction of natural dyes from plant sources is still challenging to the industry. Sodium bicarbonate solution previously identified as an efficient extractive substance has been extensively studied for a decoction of natural dyes. Critical decoction variables have been optimized namely; boiling time, material to liquor ratio (M:L), concentration of bicarbonate solution and particle size. Additionally, comparison of dye yields between the traditional maceration with bicarbonate solution and the optimized decoction was done. UV-Vis spectrometry was extensively used for quantification of dyes in the extracts during the study. The study determined that optimized decoction variables are unique to each plant and therefore practitioners in the industry have to optimize extraction for each plant species. Secondly, the optimization of decoction using sodium bicarbonate solution markedly improves on dye extraction output from each plant sample. Particle size of samples is critical to both dye yield and filterability of dye mixture it is important to use particle size range of 0.5-0.7 mm with good dye yield and moderate filterability. In addition, maceration method with bicarbonate solution gives a good dye output and can be conveniently used in place of decoction and the technique also has a net saving on cost of heating.

Automated summary

The study found that optimized decoction variables using sodium bicarbonate solution are unique to each plant species, and practitioners in the industry need to optimize extraction accordingly. Particle size of samples plays a crucial role in dye yield and filterability, with the recommended range being 0.5-0.7 mm for optimal results. Additionally, maceration method with bicarbonate solution can provide good dye output and cost savings compared to decoction.