Impacts of alkaline-electrolyzed water treatment on physicochemical, phytochemical, antioxidant properties and natural microbial load on ‘Granny Smith’ apples during storage

Abstract

Providing consumers with fresh and safe fruit can greatly increase their access to recommended daily intake of phytonutrients. Thus, this study investigated the impact of dipping in alkaline electrolyzed water (AEW) and dipping duration on the physicochemical, phytonutrients and microbial load on ‘Granny Smith’ apples. Apples treated with AEW (200 and 300 mg L−1) were compared to sodium hypochlorite (NaOCl, 200 mg L−1) and to non-treated (control) under dipping durations of 10 and 15 min. Apples treated with AEW maintained titratable acidity (TA) and total soluble solids (TSS) compared to other treatments (P > 0.05). Interaction of treatments and storage duration had a significant impact (P ≤ 0.05) on total phenolics and flavonoids contents. Apples treated with AEW better maintained antioxidant capacity compared to control. Treatments with AEW resulted in ≈2 Log reduction in total aerobic mesophilic bacteria (4.1 Log CFU cm−2 to 2.2 Log CFU cm−2) and < 1 Log reduction for yeasts and moulds (3.9 Log CFU cm−2 to 2.7 Log CFU cm−2). This study demonstrated the efficacy of electrolyzed water treatment as an alternative to conventional pack-house practices for apple fruit.