Effects of Polyethylene Thickness, Gas Combination and Temperature on Shelf Life and Quality of Strawberry

In this research, the effect of modified atmosphere packaging on the quality and shelf life of strawberries was investigated. For packing strawberries 3 gas compositions (air, N275%+CO215%+O210% and N275%+CO210%+O215%), polyethylene lining in 3 thickness of 30, 50 and 90 mm and 2 storage temperatures 4±1 and 8±1 °C were used. The effect of treatments on weight loss, firmness, soluble solids, titratable acidity and pH in strawberries at 20 days after storage was studied in a completely randomized design with factorial experiment in 3 replications. Results showed that the effects of gas composition and temperature on all of the mentioned factors are significant (P≤0.01), but the effect of the thickness of the polyethylene (PE) lining is only significant on the percentage of weight loss, soluble solids and titratable acidity (P≤0.01). The quality and quantity characteristics of strawberries were maintained better at temperature of 4 °C due to reduced breathing, evaporation and transpiration. The polyethylene lining at thickness of 90 mm, maintained the qualitative and quantitative qualities of the product due to low permeability and maintaining the moisture around the product within the package. The first gas composition (N275%+CO215%+O210%) was more suitable for keeping the qualitative and quantitative characteristics of strawberries due to more CO2 and reduced respiration. As a result, strawberries packed in a 90 mm thick polyethylene lining and a gas mixture (N275%+CO210%+O215%) at 4 °C had the best quality and highest durability.