Accelerated shelf-life testing of natural colors in model food systems Application note

By Ina Kanngiesser

Abstract

A significant part of the UK food industry is moving from artificial colors towards natural alternatives. However, natural colors are less stable and more expensive. The lack of stability can be a problem when natural colors are added to food products with a long ambient shelflife. 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 (ΔH) 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 color changes within shorter time scales.