Investigating the Synergistic Effect of Edible Coatings and Modified Atmosphere on the Quality Characteristics and Shelf Life of Pear

In this research, the effects of gas combinations, different edible coatings and storage period on the post- harvest quality of pear were investigated during storage time. The treatments were considered as two treatments of gas combinations including 10%CO2, 15%O2 (1) and 15%CO2, 10%O2 (2), five types of coating including control, propolis, 0.5 and1% chitosan and wax, and three storage time including the first, sixth and eleventh weeks. The effects of above mentioned treatments were investigated on the weight loss, firmness, soluble solids, titratable acidity and pH during 11 weeks' storage using completely randomized design with factorial test in three replicates. Analysis of variance results indicated that the effects of gas combinations, coating type and storage time, and double and triple interactions on the measured factors except pH were significant at the levels of 1 and 0.5%. At the end of the storage period, the fruit weight loss increased, which this weight loss in sample treated by the second gas combination along with wax coating and 1% chitosan coating was lower. Soluble solids and titratable acidity showed a decreasing trend over time. Total soluble solids and titratable acidity were better maintained in the samples treated by coating along with modified atmosphere 1% chitosan concentration along with the second gas combination also had a good effect on maintaining the firmness of pear fruit at 11 weeks of storage 1% chitosan coating and wax coating created a favorable atmosphere and better preserved the pear properties.  The second gas combination (and 15%CO2, 10%O2 was more suitable for pear due to higher CO2 and respiration reduction. Generally, pear coated with 1% chitosan and stored in modified atmosphere with the second gas combination 15%CO2, 10%O2 had better quality parameters than other treatments.