Peracetic acid disinfection in the food industry

Ensuring proper disinfection of surfaces in contact with food to avoid microbiological contamination is one of the main concerns of the food industry. To achieve this, and as an essential part of the implementation of a HACCP system, we must establish cleaning and disinfection protocols that are adapted to the specific needs of each facility, using detergents and disinfectants appropriate to the type of surfaces and residues present. This is achieved by maintaining the safety of the food produced, avoiding cases of food poisoning, extending the shelf life of food and avoiding organoleptic changes.

After the cleaning procedure of a food surface we must carry out proper disinfection. Within the wide range of biocidal active ingredients currently available (chlorine, quaternary ammoniums, alcohols, glutarladehyde, peroxides and peracids, amines, etc.), the main characteristics required of a disinfectant product are: broad spectrum of action, effectiveness at low doses and low environmental impact. Therefore, the choice of the disinfectant to be used will be a key point to ensure maximum food safety and security.

Characteristics of peracetic acid disinfection

Peracetic acid, formed from the equilibrium reaction between acetic acid and hydrogen peroxide, is a compound that meets the above requirements perfectly.

Broad spectrum of action at low doses

The mechanism of action of peracetic acid is based on the oxidation of the structural and functional components of micro-organisms. This same mechanism is particularly suitable for destroying the polymeric extracellular matrix generated in the presence of biofilms.

A concentration of 150 ppm of peracetic acid is sufficient to comply with standard EN-13697, which serves as a reference to validate the efficacy of biocidal products against Escherichia coli, Pseudomonas aeruginosa, Enterococcus hirae and Staphylococcus aureusmicro-organisms. To tackle Listeria monocytogenes and Salmonella typhimorium, according to EN-13697, a concentration of 75 ppm of peracetic acid is sufficient.

Peracetic acid also complies with EN-13697 fungicidal and yeasticidal standards at 1875 ppm and 1200 ppm, respectively.

Several studies show that its biocidal action, based on a high oxidising power that acts on proteins and genetic material (DNA/RNA), makes it effective against viruses at concentrations of between 400 and 1500 ppm ^[1]. It is also effective against spore-forming micro-organisms ^[2].

Low environmental impact

The high reactivity of peracetic acid ensures that it decomposes rapidly into acetic acid and water, having a very low impact on wastewater and a high level of biodegradability. Especially when compared to other widely used disinfectants such as sodium hypochlorite (which in contact with organic matter and wastewater produces harmful by-products such as chloramines, chlorophenols or trihalomethanes) or quaternary ammoniums (which are an important source of nitrogen and do not decompose as quickly as peracetic acid).

Disinfection of food surfaces with peracetic acid

All these advantages have led, in recent years, to a significant increase in the use of peracetic acid as a first choice disinfectant in the food industry. The active ingredient is registered as a biocidal active substance (according to Biocidal Products Regulation (EU) 528/2012) for application on both veterinary surfaces (TP3) and food surfaces (TP4). Consequently, the most common types of application are:

• Recirculation in CIP cleaning– This is the most common and widely used application in the food industry. The most usual concentrations of the active ingredient in the concentrated product are 5 and 15 %, with it being possible to use some tracer to facilitate its automatic control by conductivity.
• Open surface cleaning (OPC) – By means of foam projection. These are products with a lower concentration of active ingredient than that used in circuits, around 1.5%, in order to reduce the discomfort caused by the characteristic odour of the product.

Disinfection of food with peracetic acid

The advantageous characteristics of peracetic acid (low toxicity, efficacy at low doses, rapid decomposition into harmless substances…) make it an ideal food adjuvant for applications such as fruit and vegetable disinfection. Although sodium hypochlorite is still the most widely used disinfectant for this application, the advantages offered by peracetic acid are leading to its progressive introduction in the market.

The countries of the European Union benefit from the principle of mutual recognition provided for in the EU treaty. In France, peracetic acid was approved for use as a food technological adjuvant for the disinfection of spinach and vegetables prior to the packaging process. This approval is extended to the rest of the countries of the Union.

The active ingredients of peracetic acid are also accepted by the FDA for the cleaning of fruits and vegetables, according to Title 21 Part 173:

TITLE 21–FOOD AND DRUGS

CHAPTER I–FOOD AND DRUG ADMINISTRATION DEPARTMENT OF HEALTH AND HUMAN SERVICES

SUBCHAPTER B–FOOD FOR HUMAN CONSUMPTION PART 173

Subpart D–Specific Usage Additives

Sec. 173.315 Chemicals used in washing or to assist in the peeling of fruits and vegetables.

In the United States, the use of an aqueous solution of peracetic acid ^[3] is also accepted for disinfection of poultry carcasses to reduce their microbial load. This use is currently not permitted in the European Union.

Conclusions

Considering the high level of efficacy at low doses, combined with the good ecological profile and low application cost, we can conclude that peracetic acid is a particularly suitable disinfectant for a wide variety of disinfection processes in the food industry.

In order to respond to all these applications, PROQUIMIA has a wide range of disinfectant products based on peracetic acid, all duly registered:

Bibliographic references:

[1] https://aricjournal.biomedcentral.com/articles/10.1186/s13756-017-0271-3

[2] Comparative sporicidal activity of liquid chemical agents. Sagripanti & Bonifaciono, 1996

[3]https://www.ecfr.gov/cgi-bin/text-idx?SID=9e43c8243ba638d9049d069fcc658ec5&mc=true&node=pt21.3.173&rgn=div5#se21.3.173_1370

AUTOR: Dani Calvente