TITLE:
Effect of Light on Stability of Anthocyanins in Ethanolic Extracts of Rubus fruticosus
AUTHORS:
Elizabeth Contreras-Lopez, Araceli Castañeda-Ovando, Luis Guillermo González-Olivares, Javier Añorve-Morga, Judith Jaimez-Ordaz
KEYWORDS:
Blackberry; Light; Anthocyanins Stability; Ethanolic Extracts
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.5 No.6,
March
7,
2014
ABSTRACT: 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 in
combination with pomegranate, blueberry and grape. One of the main problems
with these pigments is their poor stability in solution, mainly in beverages as
liqueur and juices, which depends on 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 rates and
browning of two blackberry ethanolic extracts is to establish the conditions
for storage of liqueur without adding artificial food coloring. The initial
content of anthocyanins on extract without storage was 106 mg?l-1. The study
assessed the light irradiation effect on the anthocyanins of blackberry
ethanolic extract. The anthocyanins degradation followed the second order
reaction kinetics with respect to illuminance of the light source. The t1/2 value at high illuminance (3968.30
lx) was 28.20 hours.