Phycocyanin Thermo-photostability: an Accelerated Life-test Analysis

Phycocyanin is a natural blue colorant with antioxidant activity which can be safely used in food, however its rapid degradation is still a concern for food manufacturing. Phycocyanin is easily degraded when exposed to mid-temperatures and/or light. Several studies have been stablished the degradation kinetics of aqueous solutions evaluating temperature or light as accelerating factors using a first order kinetic model and, both factors have been studied by separate or fixing one of them to evaluate the combined effect. The aim of this work was to develop an empirical model able to predict the effect of temperature and light combined in the degradation ratio of this pigment at selected storage conditions. We have tested five correlation models to fit temperature, light and time data to the degradation ratio of the phycocyanin; these were statistically tested to select the more appropriate. This is a novelty in the study of accelerated life-test analysis of phycocyanin, since most of the models are based on one accelerating variable at the time and the relationship between accelerating variables has not been explored before. We were able to develop a methodology to evaluate the effect of two accelerating life factors at once using CPC as model which is highly precise and easy to apply. Resumen. La ficocianina es un pigmento natural color azul con actividad antioxidante que puede utilizarse de manera segura en alimentos, sin embargo, su rápida degradación sigue siendo un problema para su uso en alimentos. La ficocianina se degrada fácilmente cuando se expone a temperaturas medias o a la luz. Algunos estudios han establecido la cinética de degradación de las soluciones evaluando la temperatura o la luz como factores de aceleración usando modelos cinéticos de primer orden. Además, ambos factores han sido estudiados por separado o fijando uno de ellos para evaluar el efecto combinado. El objetivo de este trabajo fue desarrollar un modelo empírico capaz de predecir el efecto de la temperatura y la iluminación en forma combinada sobre la velocidad de degradación de la ficocianina a las condiciones de almacenamiento seleccionadas. Se probaron cinco modelos de correlación para ajustar los datos de temperatura, luz y tiempo a la velocidad de degradación de la ficocianina; dichos modelos fueron probados estadísticamente para determinar el más adecuado. Esta es una novedad en el estudio de los análisis de pruebas de vida acelerada de la ficocianina, dado que la mayorí