Combined effect of electrolyzed water (EW) and sonication with equilibrium modified atmosphere packaging for prolonging storage stability of fresh strawberry

This research focuses on the effectiveness of electrolyzed water (50 and 100 ppm for 3 min), ultrasonication (80 W for 3 min), and their combinations on fresh strawberries, which are then packaged using microperforated film to enhance their storage stability. The gas composition in the headspace, pH, soluble solids, color (L*, a*, b*, and ΔE* values), anthocyanins, total phenolics, and texture profile was evaluated for the 35 days of storage at +4 °C. The lowest weight loss was measured at about 100 ppm electrolyzed water (EW; 0.47%), and the highest one was in the control group (0.57%) after storage. At the end of the storage, O₂ in the headspace decreased from 20.90% to 10.50–8.10% and CO₂ was accumulated from 0.03% to 16.4–14.34%. The results showed that soluble solids decreased (9.95 to 8.48–7.85 °Bx) and pH values increased (3.34 to 3.79–3.91) during storage. At the end of the storage, the total phenolics in the control group decreased by the most during storage (from 1209.09 ppm to 808.00 ppm), whereas the 50 ppm EW group had the highest (931.66 ppm). Further, the significantly highest anthocyanin amount was found to be 143.86 ppm in the 100 ppm EW group at the end of 28 days of storage. The EW can significantly delay the degradation of anthocyanin over the storage period. The sonication at 100 ppm EW damages strawberry tissues, reducing their hardness. The lowest decay rate was found in fruits treated with 100 ppm EW (41.67%), followed by 50 ppm EW (58.33%), compared to the control (75.00%). This study reveals that applications of the 50 ppm EW and also 50 pm EW combined with ultrasonication have great potential in the extending storage stability of the fresh strawberries.