Studying the efficiency of treatments of ozone gas, chitosan edible coating and temperature during palm date storage and optimizing storage conditions by the method of response surface

In this research, the treatment of ozone gas and chitosan edible coating in different treatments were used during palm date storage in order to evaluate the palm date shelf life and decrease it's microbial load. In doing so, the studied dates were treated by ozone in three levels(0,2.5,5ppm) for 1 hours, then they were coated by chitosan in three levels (1,2%) in the form of response surface design .afterwards the packaging was performed by available commercial methods and until the end of experiment, they were kept in three temperatures (5,15,25oc).the results of growth of yeast, molds and coliform and total number of bacteria showed that their number is inversely related to increasing the concentration of ozone gas and used chitosan percentage and it is directly related to temperature and storage time with due attention to economic problems, there is tendency to use less concentrations of ozone gas and chitosan edible coating and also palm date storage in room temperature for long periods and based on this ,the data were optimized and the values of ozone, chitosan, temperature and time were suggested for 29% humidity date in order 2.01ppm,0.84%,22.4oc, and 33.99 days .