The reason for the improvement could be due to better
leaching of natural dye material from plant cell membranes and
mass transfer to solvent assisted by acoustic cavitation provided
by ultrasound. The results indicate that there is about 12–100%
improvement in % yield of extract obtained due to the use of
ultrasound as compared to magnetic stirring at 45 ◦C. Various process
parameters such as solvent system, temperature, ultrasound
power, amount of dye material etc. are interesting for our study as
future work. One would expect better extraction efficiency with
solvents like n-hexane for those dye materials better soluble in
organic solvents. But, our objective is to develop sustainable effective
process with aqueous system without using organic solvents.
Extraction efficiency may decrease if temperature is lowered than
45 ◦C; however, higher temperatures could affect plant material
itself as they are sensitive to the same. This novel technique can
be employed effectively for the extraction of coloring matter from
various plant resources even dispensing with conventional heating
requirements. This process provides effective utilization of natural
resources as eco-friendly method in current situation of global
environmental concern.