Total anthocyanins content was determined using two samples
containing 0.5 mL wine, 0.5 mL solution of 0.1% HCl in ethanol and
10 mL of 2% HCl aqueous solution. One sample was treated with
4.4 mL distilled water and the second with 4.4 mL of 13% sodium
bisulfite solution and the mixture was diluted (1:1). Sample absorbance
was determined at 520 nm using a blank solution prepared
from 4.9 mL distilled water, 0.5 mL of 0.1% HCl in ethanol and
10 mL of 2% HCl aqueous solution. The differences (DA) between
the absorbance value of sample prepared without sodium bisulfite
and the absorbance value of sample prepared with sodium bisulfite
were calculated. The anthocyanin content was express in mg/L of
wine and was calculated by multiplying the DA value by 875