Accelerated Shelf-life Testing of Natural Colours in Model Food

A significant part of the UK food industry is moving from artificial colours towards natural alternatives.
However, natural colours are less stable and more expensive. The lack of stability can be a problem
when natural colours are added to food products with a long ambient shelf-life. Normal shelf-life tests
are time-consuming. To investigate and identify accelerated tests for predicting the stability of natural
colors (anthocyanin, lycopene, chlorophyll and Cu-chlorophyllin) used singly as an ingredient in three
different food matrices (high-boiled sweets, gelatine jellies, juice-based drinks). Samples were stored
in a constant climate chamber at 20°C, 30°C and 40°C and exposed to high-intensity light at 4.000 Lux
with UV at 1.4 W/m2 and in dark. Loss of color was monitored in terms of change in Hue (?H) over
time (7 months at 20°C and 8 weeks at 30°C and 40°C.
Results showed that the rate of acceleration of colour degradation was affected by the food matrix and
the type of colour being used. In addition the results show that the use of elevated temperatures in
combination with light allows samples to be screened for colour changes within shorter time scales.