Development of a prototype of a colourimetric temperature indicator for monitoring food quality

Temperature greatly affects the food quality and safety. Temperature control is an important condition during distribution and storage. An intelligent and biodegradable temperature indicator packaging material was developed based on a natural and heat-sensitive pigment (anthocyanin - ATH). Different concentrations of ATH were incorporated into chitosan matrix films (2.00%, w/w) that were applied as a surface coating on card paper, forming the chitosan card paper system (CH-Sys). The novelty of this work is an alternative packaging material that is biodegradable, simple manufacturing and indicates temperature variations in a specific range by irreversible visual colour changes. The CH-Sys changed irreversibly the colour from light violet to light yellow in response to different temperature exposition (40 degrees C until 70 degrees C), independently of luminosity (0 or 1000 lx). The results indicated that the CH-Sys has a great potential for use as a temperature indicator prototype in the specific temperature range studied in this work. (c) 2012 Elsevier Ltd. All rights reserved.