Disinfection Efficacy of Slightly Acidic Electrolyzed Water Combined with Chemical Treatments on Fresh Fruits at the Industrial Scale

Abstract

The objective of this study was to investigate the efficacy of slightly acidic electrolyzed water (SAEW) combined with fumaric acid (FA) and calcium oxide (CaO) treatment on the microbial disinfection of fresh fruits including apple, mandarin, and tomato at the industrial scale. The combined treatments can significantly (p < 0.05) reduce the population of natural microbiota from the fruit surfaces and the treated samples showed good sensory qualities during refrigeration storage. In addition, decontamination of inoculated foodborne pathogens (Escherichia coli O157:H7 and Listeria monocytogenes) was carried out in the laboratory, and the combined treatments resulted in a reduction ranging from 2.85 to 5.35 log CFU/fruit, CaO followed by SAEW+FA treatment that resulted in significantly higher reduction than for SAEW+FA treatment. The technology developed by this study has been used in a fresh fruit industry and has greatly improved the quality of the products. These findings suggest that the synergistic properties of the combination of SAEW, FA, and CaO could be used in the fresh fruit industry as an effective sanitizer.

Application of electrolysed water in post-harvest treatment of fruits and vegetables

“…For instance, Tango et al 43 studied the influence of different physical and chemical treatments in combination with slightly acidic electrolysed water against E. coli and Listeria monocytogenes in apples and tomatoes, respectively and reported that while significant reductions were observed by individual applications, a combination of fumaric acid, calcium oxide and ultrasonic treatment resulted in higher decontamination. A similar conclusion was also drawn by Ding et al 44 in their work on cherry tomatoes and strawberries; and Chen et al 45 on apple, mandarin, and tomato at the industrial scale. In another study by Koide et al , 46 mildly heated electrolysed water (pH: 5.5, ACC: 23 ppm) successfully caused >2.2 log reduction in total aerobic bacteria and >1.9 log reduction in molds and yeasts in comparison with tap water treatment.…”

Combined Hurdle Technologies Using UVC Waterproof LED for Inactivating Foodborne Pathogens on Fresh-Cut Fruits

“…The population of L. monocytogenes continued to increase rapidly in the control group, while they were maintained or increased slowly in samples treated with SAEW + FA and UVC W-LED (Figure 5). Changes in behaviors of bacteria during storage after disinfection have been reported previously [32,34,36]. Total aerobic bacteria (TAB) on untreated mandarin increased faster than those on FA + SAEW treated mandarin.…”

“…Total aerobic bacteria (TAB) on untreated mandarin increased faster than those on FA + SAEW treated mandarin. After storage at 4 • C for 14 days, the final population of TAB was observed at significantly lower levels in treated mandarins than in untreated samples (p < 0.05) [36]. According to Jiang et al [32], the total number of Salmonella and E. coli in coriander treated with SAEW (60 ppm, for 5 min) and UV-LED (240 µW/cm 2 , for 30 min) and stored at 4 • C for 6 days showed a slow growth trend.…”

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

“…Postharvest application of EW on whole and fresh‐cut apples has been extensively focused on managing microbial load or reducing fungal pathogens (Kim et al ., 2000; Chen et al ., 2019; Graça et al ., 2020), impact of sensory quality (Nimitkeatkai & Kim, 2009) and reduction in pesticide residues on ‘Cripps Pink’ apples (Ferri et al ., 2016). Higher flavonoid contents was reported for sprout treated with EW compared to NaOCl and tap water treated samples at 4 °C for 7 days (Zhang et al ., 2019).…”