# Application of Electrolyzed Water in the Food Industry: A Review
## 2 Application of Electrolyzed Water in the Food Industry
### Types of Electrolyzed Water
Various EW-producing systems are summarized in Table 1. The factors determining the physicochemical properties of EW include current values, electrolysis time, water flow during electrolysis, and sodium chloride concentration [74]. Currently, systems for the production of SAEW are developed that provide the basis for the development of domestic and commercial SAEW generators for household and industrial utilization [75]. The purity levels of the water from different purification sources is discussed below in Table 1.  
EW has antimicrobial properties against food pathogenic microorganisms attached to cutting boards, kitchen surfaces, poultry and meat carcass, cell suspensions, and vegetables [73]. The overall antimicrobial activity and action mechanism is not completely understood, and further research is required. Some researchers consider the chlorine present in EW as the major antimicrobial, while others regard ORP as the major factor responsible [73]. Other factors affecting the sanitization efficiency of EW include the water flow rate, current, salt concentration, electrolytes, hardness of the water, water temperature, and electrode material [73]. The effect of ORP, ACC, and pH on the antimicrobial properties of EW is strong, as pH influences the generation of chlorine species. The ORP and ACC of electrolyzed water decline sharply with the upsurge in pH from acidic (2.5) to alkaline (9.0). At pH 9, the antimicrobial efficiency ceased [77]. AEW, owing to its low pH, increases the vulnerability of bacteria towards chlorine in the form of HOCI and thus decreases bacterial growth. Some researchers have proposed that the increased ORP of AEW determines its antimicrobial efficiency [73]. An increasing ORP facilitates the oxidation of sulfhydryl mixtures in the bacterial cell, destroys metabolic pathways, and facilitates bacterial inactivation [73]. Thus, as per principle, a high ORP and low pH facilitate the inactivation of microorganisms. On the other hand, an increased flow rate of water results in an upsurge in current due to the increased production of salts per unit time [65]. This \"acidic electrolyzed water\" can have its pH increased by mixing in the desired amount of hydroxide ion solution from \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Water** & **Detected Elements** & **C+2 (mg)** & **Mg+2 (mg)** & **K+ (mg)** & **Na+ (mg)** \\ \hline Ordinary tap-water & pH 8.00 & 24.42 & 4.98 & 5.04 & 46.60 \\ Ultrapure water & pH 8.23 & 5.32 & 0.83 & 0.94 & 2.88 \\ Acid electrolyzed water & pH 3.00 & 13.55 & 2.92 & 1.71 & 19.47 \\ SAEW & pH 5–6.5 & 16.53 & 3.41 & 4.96 & 56.03 \\ \hline \hline \end{tabular} Data from [PERSON] et al. [76].  
\end{table} 
Table 1: pH and concentration of different minerals in water from different sources. the cathode compartment, yielding a solution of hypochlorous acid (HOCI) and sodium hydroxide (NaOH). The varying average increase or decrease of the effectiveness of EW is due to its influence on the generation of the chlorine concentration. It has been reported that an increasing average improves the sanitizing efficiency of EW, for example, by increasing the current from 1.15 to 1.45 A, a log reduction between 4.9 and 5.6 CFU/mL for _Listeria monocytogenes_ and _E. Coli_ O157:H7 was found. Moreover, the ORP, ACC, and pH also increased by increasing average [78]. The storage conditions also influence the properties of EW. In open conditions, due to the evaporation of chlorine and the breakdown of HOCI, the sanitizing efficiency of EW is diminished [71]. In closed conditions, chlorine losses occur by self-decomposition, but these losses are lower than in open conditions. The ACC of low concentration electrolyzed water diminishes from 10 to 0 mg/L in 7 and 21 days, respectively, under open and closed conditions. However, the pH increases, the ORP decreases, and the bactericidal activity is better sustained in closed storage conditions (14 days).