Determination of ascorbic acid in natural fruit juices using digital image colorimetry

This work proposes a procedure using digital image colorimetry for the determination of ascorbic acid in natural fruit juices. The method was established by measuring the color of the iron(II)-1,2 ortho-phenanthroline complex. The digital images obtained during the experiments were stored in JPEG format, and the region of interest (ROI) was submitted to decomposition in color values according to the RGB additive color model. However, the analytical procedure recommended the employment of the blue channel because it presented higher sensitivity than the red and green channels.