Editors’ note: This is part 1 of a three-part series on environmental monitoring. Parts 2 and 3 will publish in the October/November and December/January issues of FQ&S.
It’s business as usual in the sanitation department during routine operations. Procedures change when there are out-of-specification (OOS) results from environmental sponge tests—or do they?
Reclean, resanitize, and retrain are three common approaches for corrective actions. During this time, it could be argued that the same sanitation procedures may be conducted, regardless of the circumstances—just more often.
This will be a three-part series. Part 1 will explore the first steps involved in implementing a cleaning/sanitation process: the selection of chemicals and developing a master sanitation plan. Part 2 will discuss differences in cleaning/sanitation procedures when normal conditions are not occurring, such as when there is an OOS, maintenance, or construction event. In Part 3, we’ll cover procedures for use during extenuating circumstances such as complex maintenance procedures, construction, and pathogen investigations.
During the recent coronavirus outbreak, food companies have augmented sanitation activities, focusing on the well-being of employees. While dealing with these unprecedented times, manufacturers should not lose sight of the sanitation procedures important to the maintenance of sanitary conditions in the production of products.
A solid program starts with the development of two main components: sanitation standard operating procedures (SSOPs), based on four cleaning dynamics, and a master sanitation schedule outlining what is cleaned or sanitized, and how often.
Sanitation Standard Operating Procedures
The goal is to define the activities encompassing cleaning and sanitation. This is a multi-stage process, and the documents will evolve over time. First, consider developing general cleaning instructions to efficiently capture company policies. Second, identify soil components for detergent selection,
General cleaning instructions. For efficiency, combine common/recurring SSOP practices (training, storage, responsible parties, chemicals and concentration, and personal protective equipment [PPE]) into general cleaning instructions that are performed prior to or during all circumstances (routine operations, OOS, extenuating circumstances) where cleaning and sanitizing occur.
Identify soil components. Detergent selection is driven by functionality, which is driven by the physical attributes of the soil (products/ingredients) and water. Specifically, identifying the pH, mineral content, and type of organic soil will lead to the identification of the best detergent for their removal.
The pH of water is typically between 7 and 8, which usually does not negatively affect the detergent activity, but it could affect sanitizer selection. The greater deviation of pH from neutrality (pH 7), the greater the potential exists for detrimental chemical effects. Product pH will have similar repercussions. Acid soils, such as citrus, will react with alkaline chemical products, reducing their effectiveness, and vice versa.
Water chemistry should be taken into consideration at the facility. Water hardness may affect the ability of the chemistry to perform by reducing detergent foam formation or forming scale in clean-in-place (CIP) systems. Sometimes, minerals are embedded in a complex matrix of minerals, fats, and proteins and are termed milkstone, beerstone, and waterstone.
A film on a piece of equipment can be identified as mineral by applying an acid to the surface. If the film is removed, the soil is a mineral. Mineral deposits and film can usually be prevented using alkaline detergents that contain sequestering or chelating agents, or an agent that binds to the mineral, keeping it in solution so it is easily washed away during a rinse step. Alternatively, mineral deposits may also be removed by periodic applications of an acid, if the water does not have a high silica content. When hot water is used, if the water is hard (>4 grains per gram of calcium carbonate), there is a greater opportunity for it to precipitate (fall out) from the water and adhere to surfaces, causing a film. This film can serve as a base onto which bacteria can adhere and act as a protectant. This increases the difficulty of their removal and shields them from sanitizers.
Organic soils (carbohydrates, fats, oils, proteins) require different methodologies for cleaning. For best results, all matrices should be identified prior to chemical selection and cleaning dynamics to SOP development.
- Carbohydrates. Some carbohydrates, such as sugars, may only require water for removal, while others, such as starch, may need a detergent. A cold water pre-rinse is best for starchy soils because a hot rinse can cause the soil to stick to the surface, making it difficult to remove.
- Oils and fats. Oils and fats may necessitate the additional chemical reactions of saponification or emulsification for removal. Saponification, conversion of fat/oils to soap and alcohol, occurs by the addition of alkaline (caustic) and hot water. Emulsification is the suspension of a typically immiscible liquid in another liquid. The process breaks down the surface tension of fat/oils, allowing for mixing of water. Once suspended, the fats/oils are further broken into small fat globules, allowing more mixing into water and permitting easier elimination through rinsing.
- Proteins. Proteins are generally the most difficult soils to remove. Routine cleaning of protein processing equipment is best achieved through the addition of chlorine to an alkaline solution. The chlorine peptizes (breaks down) proteins into smaller amino acids, facilitating removal from the system. Although effective, it is not recommended in all applications, such as RO membrane systems or evaporators. Additionally, when proteins are heated, they unfold (denature) and will adhere to a surface. In this state, they can be difficult to remove. Cold residues are easier to purge.
Once the pH, mineral content, and organic content of the soils are identified, the chemistry of the cleaning detergents may be determined and the best-fit product selected. In choosing the chemistry, compatibility with surfaces must be considered. While soil identification might lead to a strong acid product, the equipment may not be compatible with that selection, although some products may have choices within their lineups (e.g., soft metal safe).
Cleaning Dynamics
Once detergents are chosen, the procedures for their use will depend on three additional components: application time, water temperature, and mechanical action. Together, the four components are cleaning dynamics devised by Herbert Sinner in the 1950s and dubbed the “Sinner’s Circle” (See Figure 1). A balanced cleaning process requires a percentage of the components totaling 100 percent. If one component is changed, the others must increase or decrease to balance.
Product labels indicate typical time, temperature, and concentrations, but adjustments may be needed for time constraints or lack of available mechanical action (Figure 2). Increased CIP turbulent action increases solubility of most materials, rendering them easier to remove. Generally, the temperature range of cleaning is between 90°F and 185°F. Temperatures above 185°F may induce reactions that bind proteins more tightly to a surface, and in those below 90°F, (butter) fat remains a solid. If cleaning fats, the minimum effective cleaning temperature is 5°F higher than the fat melting point. A general rule of thumb is that cleaning temperatures should be 5°F to 10°F higher than the processing temperatures.
Mechanical action will be dependent on the type of action performed. Hand or manual cleaning may require an extended time period to ensure the removal of all matrices. CIP fluid flow applies the force or turbulence as the mechanical action. A fluid velocity of five feet/second for 1.5- to 2.5-inch pipes gives the minimum result for effective cleaning. For three-inch lines or larger, eight feet/second is recommended. This velocity results in the amount of flow necessary to achieve turbulent flow instead of laminar flow in pipes.
Time is a valuable cleaning process resource. Limiting the time needed for cleaning will only lead to later implications, such as ineffective sanitizer action, because without removal of soils, the sanitizer will not reach the microbial cell surface, causing its destruction.
While increased detergent concentration may give the appearance of improved soil removal, there is a minimum amount for effectiveness and an economical amount. Too much detergent may not be rinsed effectively, leaving a residue.
Sanitation
Only after the complete removal of soils can sanitizers be effective for microbial elimination. Selection of sanitizers depends on the nature of the processing environment and biological hazards identified through the Hazard analysis and critical control points (HACCP) risk assessment. Sanitizers follow the same dynamic wheel as cleaning, except soil removal is substituted for mechanical action. Sanitizer application must be conducted at the strength and time listed on the product label, especially for food contact surfaces, as the EPA administers the registration of chemical sanitizers and antimicrobial agents for use on these surfaces.
Sanitizers include chlorine, alcohol, quaternary ammonium, and peroxyacetic acid-based compounds. Each sanitizer has proven efficacy against a broad spectrum of microorganisms and has a different mode of action, which leads some manufacturers to rotate sanitizers. For example, chlorine dioxide is effective against Gram-positive and Gram-negative bacteria but not as effective against yeasts. An oxidation mode of action (chlorine) may be counteracted by cell lysis (quaternary ammonia).
Master Sanitation Schedule
Within each area, items cleaned and sanitized are noted on a master schedule serving as a checklist or accounting of when items are cleaned and by whom. You can view a sample schedule on our website at foodqualityandsafety.com.
A cleaning and sanitation program involves a chemical analysis of the soils to select the best chemical(s) for cleaning. Sanitizer selection includes the HACCP risk assessment and adds equipment composition to safeguard against damage. Under normal operations, the master cleaning and sanitation can be followed as it is written. In Part 2 of this series, we will address necessary alterations in the cleaning and sanitation regime when a plant experiences OOS results, equipment maintenance, and/or construction.
Dr. Deibel, a Food Quality & Safety Editorial Advisory Panel member, is the chief scientific officer at Deibel Laboratories, where she is responsible for leading the technical staff in research, food safety, and regulatory issues. Reach her at [email protected]. Baldus is food safety program manager for Hydrite Chemical Co. Reach her at [email protected] or [email protected].
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