Effect of UV treatment: Appropriate amount of MFR extract was diluted with prepared ethanol at pH 5.0 and the total pigments before UV treatment was determined at 458 nm. For UV stability, 10 mL of the extract were placed in each of the three valcon test tubes and placed under UV light for 0, 1, 2, 3, 4 and 5 hours.
The degradation of all pigment treatments was followed by measurements of colouring power of the samples at 458 nm.