Vitamin C kinetic degradation of strawberry juice stored under non-isothermal conditions

Abstract

Strawberries are a good source of nutritional compounds and may be considered among the fruit most rich in ascorbic acid (AA). Strawberry juice is easily damaged in transit due to temperature fluctuations that may significantly reduce shelf life. In this way, the use of “best before” and “use by” dates should be reconsidered in the light of temperature variability during transport or storage. Kinetic degradation of ascorbic acid and shelf life estimation of strawberry juice stored under non-isothermal conditions was performed using a Weibullian-logistic model. A kinetic order of 1.1 was estimated as the best value to fit AA degradation under isothermal conditions and may be considered as the value for this particular medium. Moreover, the Weibullian-logistic model well fitted AA degradation under non isothermal conditions and may be used to predict shelf life under different fluctuation temperature histories. On the basis of temperature profiles considered in this paper, a retention of 46.8% and 42.7%, respectively for experimental and predicted data after 15 days were measured. Furthermore, it was showed a significant decrease of shelf life (about 5 days) for samples exposed to fluctuation temperature in comparison whit samples kept at constant temperature.