Fect of packaging materials and storage on local orange juice by using models systems

الملخص EN

model system of local orange juice 13% packaged in glass and plastic bottles and stored at 20,30 and 40 °C for four months in light and without light.Results showed that increasing temperature and period storage caused decreasing in ascorbic acid content and increasing nonenzymatic browning,The stability of ascorbic acid and reduced of nonenzymatic browning was better in the paked in glass bottles.The results of ascorbic acid degradation kinetic parameter showed that the order of the reaction is First and there was an increasing in rate constant(K)in the case of increasing of the storage temperature and in the samples of glass bottles,but the rate constant was decreased in the stored dark.The activation energy(Ea) of samples stored in the light,and decrease in plastic bottles.It was found that the shelf life of samples decreased with increasing the storage temperature .We got in this study the predication equation to get the amount of ascorbic acid at any time of storage.