Effect of Gaseous Ozone and Heat Treatment on Quality and Shelf Life of Fresh Strawberries during Cold Storage

Ozone is a powerful oxidant agent which is used in foods preservation on account of its ability of killing microorganisms. In the present study, the combined effects of ozone gas treatment and heat treatment on the physicochemical and sensory characteristics and shelf-life of strawberries kept under refrigeration were investigated. Strawberries were heat treated, ozonated at concentrations of 0.5, 1.0, and 1.5 ppm for 40 min and ozonated at the above-mentioned conditions in combination with heat treatment. Ozone and heat treatment affected significantly (p < .05) weight loss percentage and titratable acidity. Total soluble solids (TSS) content was affected significantly by heat treatment, ozone treatment at concentrations of 0.5 and 1.0 ppm and by the ozone treatments at all concentrations plus heat treatment. Color parameters L*, a*, b*, and pH were affected significantly by ozonation at concentration of 1.5 ppm plus heat treatment. Firmness, pH, and color parameter L* were affected significantly by ozonation at 1.0 ppm. Heat treatment and ozonation at 1.0 ppm plus heat treatment also affected firmness. In conclusion, strawberries treated with ozone at a concentration of 0.5 ppm and at 0.5 ppm plus heat treatment recorded a higher score in sensory analysis and slightly longer storage time.