Objective: To understand the disinfection effect of electrolyzed oxidizing water disinfectant on kitchenware, guide practical application, and reduce the incidence of intestinal infectious diseases. Method: Referring to the national hygiene standard for disinfection of tableware (GB14934-1994), two hygiene indicators, total bacterial count and coliform group, were detected. Before disinfection, various kitchen utensils were tested, and the qualified rate of bacteriological indicators was 47.92%. The tableware was soaked and disinfected with 40mg/L electrolyzed water disinfectant for 2 minutes, and the qualified rate of bacteriological indicators reached 100%. The table surface needs to be wiped and disinfected with 80mg/L electrolyzed water disinfectant solution for 2 minutes. Conclusion: When disinfecting by wiping, it is necessary to increase the concentration of disinfectant or extend the disinfection time appropriately.

The large cafeteria has multiple functional rooms, a humid environment, and high operating temperatures, which can easily breed flies, mice, cockroaches, and other pests. In addition, with a large number of diners, a wide variety of food options, and busy operations, cross contamination can easily occur. Public tableware can be contaminated with various pathogenic microorganisms such as hepatitis virus, dysentery bacillus, typhoid bacillus, etc. if not properly disinfected and reused. Regularly disinfecting tableware, drinking utensils, kitchen utensils, containers, surfaces of objects, and cafeteria environment is an effective means of reducing the occurrence of intestinal infectious diseases. This experiment observed the disinfection effect of electrolyzed oxidizing water disinfectant on kitchen utensils in large canteens. The results are reported as follows.

1. Materials and Methods

1.1 Sampling

Soak a 2.0cm × 2.5cm sterilized filter paper evenly in sterile eluent, apply it to the surface of the sampling item, and apply 10 filter papers to bowls, plates, cups, cutting plates, cutting tools, etc. After 5 minutes, remove them and combine them into one sample (equivalent to a sampling area of 50cm2, special samples such as sampling plates, spoons, and wine glasses, apply 2 filter papers on the surface, and combine every 5 pieces into one sample). Put them into a triangular flask containing 50ml sterilized physiological saline (chopsticks: take the lower part of each pair at 12cm (12cm × 2cm × 2cm), place them in a 50ml sterilized saline test tube, shake thoroughly 20 times, and make the original solution), and test within 4 hours. Two hygiene indicators, total bacterial count and coliform group, were sampled and tested before and after disinfection.

1.2 Disinfection

The oxidation potential disinfectant is produced by Xiamen Penglong Technology Development Co., Ltd. It is prepared into a disinfectant according to the instructions and the concentration of the disinfectant is determined by iodometric method. Tableware is disinfected by soaking, and the surface of the dining table is disinfected by wiping.

1.3 Result judgment

Refer to the national hygiene standards for disinfection of tableware (GB14934-1994). (1) Detection of total bacterial count: Shake the sampling tube on the mixer for 20 seconds or vigorously shake it 80 times. Use a sterile pipette to draw 1.0cm of the sample to be tested and inoculate it into sterile petri dishes. Inoculate 2 petri dishes for each sample, and count the viable bacteria using the pouring method. Total bacterial count (cfu/cm2)=(number of colonies on the plate x dilution factor)/sampling area (cm2). (2) Detection of coliform bacteria: Take 1.0cm of the sample solution to be tested, add it to the corresponding single or double lactose bile salt fermentation tube, and incubate at 37 ℃ for 24 hours. If the lactose bile salt fermentation tube does not produce acid or gas, it can be reported as negative for coliform bacteria. If there are doubts, separate and cultivate them.

Qualification criteria: The total number of bacteria should be less than 30/cm2, and the coliform group should be less than 3/100cm2.

2. Result

2.1 Before disinfection, tableware, kitchenware, dining table surfaces, etc. were tested, and the qualified rate of bacteriological indicators was 47.92%. Among them, chopsticks, cutting boards, knives, and the surface of the dining table are the most severely contaminated, with a bacterial index exceeding the standard rate of 100%.

2.2 Disinfect tableware and kitchen utensils soaked in 40mg/L of oxidizing water disinfectant for 2 minutes, sample and test for bacteriological indicators, and the pass rate is 100%. Wiping and disinfecting the desktop with 40mg/L for 2 minutes is still not qualified. Disinfect with 80mg/L electrolyzed water disinfectant for 2 minutes, and the qualification rate of tableware, kitchenware, and tabletops is 100%.

3. Discussion

With the arrival of summer and the rise in temperature, it has become a high-risk period for intestinal infectious diseases, and outbreaks of foodborne infectious diseases and collective food poisoning incidents occur from time to time.

Disinfection of kitchen utensils is of great significance in controlling the spread and prevalence of intestinal infectious diseases and ensuring the health of diners. There is no experience in using oxidative potential disinfectants for disinfecting tableware in large canteens, nor is there sufficient laboratory evidence.

The observation results of this experiment show that when bowls, chopsticks, cutting boards, knives, etc. are soaked and disinfected with 40mg/L electrolyzed water disinfectant for 2 minutes, the qualified rate of coliform bacteria and total bacterial count reaches 100%. Desktop wiping and disinfection require the use of 80mg/L electrolyzed water disinfectant solution for 2 minutes. When disinfecting by wiping, it is necessary to increase the concentration of disinfectant or extend the disinfection time appropriately.

Pre disinfection testing showed that the failure rate of tabletops, chopsticks, cutting boards, and knives reached 100%, and most of the samples had bacterial indicators exceeding the standard by more than 10 times, making them the key disinfection targets.

Author affiliation: Disease Prevention and Control Center of Shenyang Military Region, 100031.