Monitoring and analysis of chlorine dioxide in the food industry

Currently, one of the most dynamically developing market segments in Russia and the CIS is the food industry. Every year, more and more new types of food products, both imported and domestic, appear on store shelves. It is known that the production and sale of food products is associated with an increased risk of microbial contamination, and, as a consequence, with the likelihood of food toxicoinfections for the final consumer. One of the most dangerous food categories in terms of microbiological risks realization is fresh vegetables (including salad crops) and fruits.

With the growing demand for healthier lifestyles, the market for freshly cut vegetables with minimal processing is growing all over the world. Therefore, manufacturers of such products are increasingly concerned about cleaning technologies that allow them to produce safe and quality products. In addition to desinfection, equipment used to process these products must be desinfected frequently enough during the manufacturing process to prevent biofilm formation that can contaminate subsequent product batches.

When processing fruits, fresh salads, herbs and vegetables, it is not possible to carry out a heat treatment stage to fight microorganisms.

The fresh cut fruit and vegetable industry is significantly different from ready-to-eat prepared foods; with salads, fruits and vegetables, it is not possible to carry out a heat treatment stage to combat microorganisms. It has been shown that both pathogenic and non-pathogenic microorganisms form biofilms on the surfaces of fruits and vegetables, as well as on surfaces which are in contact with food, on processing equipment. Such interactions allow microorganisms to effectively resist the antimicrobial activity of the disinfectants used and, therefore, are a source of further product contamination.

Some European countries are promoting the use of drinking water instead of water containing chemical disinfectants for washing fresh cut vegetables. This water, if recycled, will soon be heavily contaminated with microorganisms. Options: use fresh water only once and then drain it; or treat with a disinfectant to control the level of microorganisms in the circulating water. While the disinfectant is primarily intended to control the germ levels in the water, it looks like it also affects the germ levels in the washed product.

Chlorine-based disinfectants

The use of disinfectants in the food industry is an important tool in killing microorganisms and ensuring food quality for preservation, extending shelf life, sterilizing equipment, and eliminating unwanted odors produced by bacteria during storage and transportation of food.

The production of freshly cut vegetables and fruits usually involves peeling, pruning, core removal, slicing, chopping, washing, centrifugal drying and packaging. Cutting increases the area of damaged tissue available for microbes to multiply, which contributes to the rapid destruction of the fruit. Microorganisms can also settle in inequality on the surface of vegetables, adhere firmly and form biofilms. Their shelf life is also significantly reduced when processed. For these reasons, halogenated disinfectants such as chlorine are used to disinfect water, food and processing equipment.

A very popular disinfectant is chlorine dioxide, which can be safely used to wash fruits and vegetables, seafood, meat, mushrooms and many other foods. The decisive factor is the ability to kill bacteria, including potentially harmful pathogens such as E. coli, as well as kill spores, viruses and fungi, reducing the risk to the consumer and increasing the shelf life of the product. ClO2 does not affect the taste, smell or appearance of food.

From the above, it's easy to conclude that chlorine dioxide is an ideal disinfectant and decontamination agent in the production, processing and final preparation of food products. However, there is a desire to minimize the use of chlorine in food processing due to the potential health effects of consumers, while ensuring product safety and quality. Chlorine dioxide is safe to use and meets the requirements of the food industry, but only at the correct concentration.

The ClO2 concentration is highly dependent on the type of product and the corresponding microbiological contamination level, and ranges from 2 ppm (to keep residual chlorine dioxide around 0.5 ppm) to 5 ppm. At a definitely higher dosage, chlorine dioxide can also be used to treat water used for washing, transporting, handling and sorting fresh produce before sale and for pre-cooling, which is intended to slow down the maturation / overripe processes and the development of pathogens (especially fungi).

Chlorine dioxide monitoring

If the process is properly controlled, your end result will be a safe food product with a longer shelf life.

The use of chlorinated water in the food industry has limitations that include loss of product quality if levels are excessive, metal corrosion at low pH or excessive concentrations, and the formation of chlorine gas at low pH. Most factories have control means to ensure that chlorine dioxide concentrations are within normal limits and are controlled without compromising product quality, worker safety and equipment surfaces. The effect of high levels of chlorine on food properties is manifested by discoloration or unacceptable taste or odor.

Since the chlorine content of process water is considered a critical control parameter in manufacturing, the ability to control the process is critical to maintaining its integrity.

Chlorine dioxide analyzer Hach 9187 sc

Chlorine dioxide disinfection of water is becoming more common as businesses seek to reduce the formation of disinfection by-products in the finished product, but the process of monitoring it is not as simple as it seems at first glance.

Accurate measurement of ClO2 as a control parameter can be difficult due to changes in the pH of the sample, the influence of chlorine and juices from product slices that enter the water.

Practice and research have proven the impossibility of using classical photometric methods for measuring the chlorine content in water used for disinfection of freshly cut salad crops, vegetables and fruits due to the influence of juices, which are mixed with water. As a result, when using photometry, you will get unreliable results.

Advanced non-reagent monitoring technology, combined with continuous real-time analysis directly in the line, helps fresh fruit and vegetable growers accurately detect and analyze chlorine dioxide (ClO2) even at concentrations as low as 0.01 mg / L.

The Hach 9187 sc Chlorine Dioxide Analyzer is an industrial, one-channel, online instrument that measures ClO2 in factories where parts per billion (ppb) and parts per million (ppm) ClO2 monitoring is required. The amperometric method of measuring the concentration of ClO2 is used.

The selective membrane prevents the interference of any compounds in the water, providing reliable chlorine dioxide analysis results.

Desinfection technologies to produce safe and quality products

• The use of chlorine dioxide when washing fresh vegetables and fruits allows you to minimize the number of harmful microorganisms that can harm the health of the consumer, as well as form biofilms on process equipment.
• A critical element of disinfection is accurate dosing and monitoring of the ClO2 level in the water. Adding chlorine dioxide in the right concentration saves material, protects the environment and the health of the end user of your product.
• The Hach 9187 sc Chlorine Dioxide Monitoring System has demonstrated that it is the “brain” of qualitative analysis and can selectively measure the ClO2 level, regardless of the interference that may arise from juices produced by vegetables, fruits and freshly cut salad crops. Thus, proving the inapplicability of classical photometric methods in the analysis of water used for disinfection of fresh agricultural products.

AquaAnalytics®️ is the official representative of Hach Lange in Russia and the CIS countries. Contact us and our specialists will select laboratory and industrial equipment for monitoring chlorine dioxide in your production.

Representative office in Russia: +7 (495) 201-53-02 info@aquaanalytics.ru

Representative office in Uzbekistan: +998 (90) 174-57-84 info@aquaanalytics-tekhnika.ru