Effect of Light on Stability of Anthocyanins in Ethanolic Extracts of Rubus fruticosus.

Blackberry (Rubus fructicosus) is one of the fruit with the highest concentration of anthocyanins;however, its use is limited for making jams, jellies and liqueur, and recently, fruit concentrates incombination with pomegranate, blueberry and grape. One of the main problems with these pigmentsis their poor stability in solution, mainly in beverages as liqueur and juices, which dependson factors such as chemical structure, pH, temperature, light, water activity, and presence of oxygen.The effect of light on total monomeric anthocyanins content as well as the degradation ratesand browning of two blackberry ethanolic extracts is to establish the conditions for storage of liqueurwithout adding artificial food coloring. The initial content of anthocyanins on extract withoutstorage was 106 mg?l?1. The study assessed the light irradiation effect on the anthocyanins ofblackberry ethanolic extract. The anthocyanins degradation followed the second order reactionkinetics with respect to illuminance of the light source. The t1/2 value at high illuminance (3968.30lx) was 28.20 hours