Requirements for direct contact of food with compressed air

Today, with the highly developed automation of food enterprises, compressed air has been widely used. For some special processes in the food industry, compressed air may also come into direct contact with the product. Like some special chemical areas, the air may have been polluted. If the pollutants are not separated and directly contact with food, various physical and chemical reactions such as adsorption and absorption may occur with food, which will eventually cause physical harm to consumers and bring unnecessary losses to enterprise production.

Today, let's talk about the use of compressed air in food companies.

1. Correct Understanding of Compressed Air

1. Direct contact: that is, "compressed air is used as part of the production and processing process, including the packaging and transportation of safe food", and compressed air in direct contact with the finished food or its ingredients is used as part of the production process.

For example: using air cooling and moving the finished product from one process to another, compressed air should have the same quality priority as any other ingredients.

Indirect contact: refers to the compressed air discharged into the general environment of the food, including its packaging, processes and production equipment or the storage location of the food and its ingredients.

For example, use compressed air to blow PET bottles or prepare and open bags before pouring food, similar to the valve activated by compressed air near the finished food or its ingredients.

Non-contact: Food production enterprises tend to "over-protect" air compression systems, so it is equally important to pay attention to non-contact low-risk systems. Most factories have a significant proportion (more than 50%) of compressed air entering "factory air" applications, which will not come into contact with food or food packaging machinery at all.

2. regulations and standards

adhering to these requirements is important to ensure optimal food safety and to reduce risks for consumers. International standards are helpful in this regard.

For example, ISO 8573-1:2010 sets out the key quality requirements for compressed air and specifies the maximum values of contaminant content and particle size that can be present in each class.

In order to ensure that the quality of the gas supply treatment in the automation solution is up to standard and energy-efficient, parameters such as the quality level of the following substances are required: solid particles, moisture content and total oil content.

(1) Compressed air in direct contact with dry food (e. g. cereals, milk powder)

compressed air is used for conveying and mixing, usually also for food production. It comes into direct contact with food. Because these are dry foods, there are more stringent requirements in terms of air humidity.

The following are the compressed air quality classifications in ISO 8573-1:2010 applicable to this situation:

-Solid particles: Grade 1

-Water: Level 2

-Oil: Grade 1

(2) Compressed air in direct contact with non-dry food (e. g., beverages, meat, vegetables)

compressed air is used for conveying and mixing, usually also for food production. It comes into direct contact with food.

The following are the compressed air quality classifications in ISO 8573-1:2010 applicable to this situation:

-Solid particles: Grade 1

-Water: Level 4

-Oil: Grade 1

the British Retail Consortium (BRC)/British Compressed Air Association (BCAS) food-grade compressed air code of practice, the "Code of Practice" also provides the minimum purity and quality standards for compressed air used in the food and beverage industry.

Selection of 3. compressed air system

the food industry is faced with the problem of how to choose a safe and effective compressed air system. In order to make a reasonable judgment, we must first determine the way in which enterprises use compressed air in the production system.

Regular risk assessment is also an effective means of monitoring whether there is a risk of compressed air to food safety. Manufacturers need to pay close attention to the potential risks associated with compressed air pollution in food production. After preliminary risk assessment and classification of compressed air use, it is necessary to ensure that each category and application provides the correct air quality and meets applicable air quality standards according to practical norms.

Manufacturers can choose from a wide range of compressed and purified air equipment to minimize the risk of food contamination. Many enterprises do not know the pollutants and pollution sources in the compressed air, so they ignore the compressed air in the hazard analysis process.

the hazards of compressed air:

biological hazards: 1m3 of outside air can contain up to 100,000,000 microorganisms. These microorganisms are sucked into the compressor and enter the compressed air system. If not controlled, the microorganisms will grow rapidly in the compressed air system. The pressure dew point higher than -26 ℃ will inhibit the reproduction or growth of microorganisms. Refrigeration and drying equipment reaching 3 ℃ pressure dew point will not inhibit the growth of microorganisms. In order to inhibit, control equipment with a pressure dew point of -40°C shall be used.

Chemical hazards: due to the compressed air in the process of the need to use a lot of lubricating oil, and these oil if not controlled with compressed air will enter the food, food additive contact surface, or even direct contact with the product.

Physical hazards: There are a large number of dust particles in the air. Due to the particularity of compressed air, the dust particles are gathered in the compression process, and then the compressed air pollutes the food or food additives.

Application of HACCP Principle in Compressed Air System

HACCP Principles

compressed Air Disposal Requirements

hazard analysis identifies potential hazards to food safety (contaminants)

10 contaminants present in a typical compressed air system (water vapor, microorganisms, atmospheric dust, oil vapor, water mist, condensate, liquid oil, oil mist, rust, pipe exfoliation)

identify where the CCP's hazards (contaminants) may enter throughout the production process Establish critical control points

use compressed air at every point in the manufacturing process

establish corrective and preventive actions at all CCP points

installation of filtration and drying (purification) equipment

monitoring corrective and action at CCP points

periodic air purity sampling for compressed air systems

when the corrective and preventive measures of CCP cannot be met

recording process followed by employees in the event of a quality incident

maintain logs of all CCPs and take control measures to prevent potential problems

hazard analysis details, all CCP points and relevant sampling and test records available for review

after investigation, it is generally believed that there are two main sources of pollution in the new compressed air system-the atmosphere and the compressor that are sucked into the system.

Traditional compressors often use oil for lubrication and cooling, and may carry the oil downstream. If the oil is not processed, the oil will reach the critical control point through the system. Currently, in order to avoid compressor oil pollution and eliminate the main source of pollution, most food and beverage companies are adopting air compression systems with "oil-free" compressor technology.

In terms of risk analysis, food manufacturers should consider the impact of various potential risks, such as any failure of internal sealing devices or leakage of lubricants and oil. Using a 100 percent oil-free compressor minimizes the potential risk of introducing more pollution from the air compressor.

In addition, the compliance of the compressed air system with the equipment manufacturer's guidelines will help ensure that the system is safe, reliable and efficient. It should be known that the main service objects of food producers pay great attention to the safety of the food they buy. Therefore, all service operations, inspections, inspections and accidents related to the air compression system during the production process should be well documented.