Question

Why does maximum absorbance occur for Anthocyanins at the 500 ~ 600nm range. Additionally how can one explain the high absorbance at lower pH for anthocyanins compared to higher pH values ?

Answer 1

Anthocyanins have maximum absorbance at the 500-600nm range due to the extended system of conjugated pi bonds. The high absorbance at lower pH compared to higher pH values is due to changes in the molecular structure.

Step-by-step explanation:

The maximum absorbance range of anthocyanins at 500-600nm is due to the extended system of conjugated pi bonds in the molecule, which causes it to absorb light in the visible range. The compound appears red to our eyes because the peak absorbance at 524 nm falls within the green region of the spectrum.

Regarding the high absorbance at lower pH values compared to higher pH values for anthocyanins, the color changes are due to changes in the molecular structure. At lower pH, the anthocyanin molecule takes on a more stable structure, which allows it to absorb light more efficiently, resulting in higher absorbance. At higher pH, the structure of the molecule changes, leading to a decrease in absorbance.