Using Water More Efficiently in Beef Packing Plants

Background

Packing plants use a time-tested approach to clean their facilities. The first step is to remove fat and meat scraps from equipment, floors and walls using high pressure hot water. Next, surfaces are cleaned using detergent. Finally, sanitizers are used to kill the remaining bacteria. Processing companies want to reduce their water use as part of their environmental goals and to reduce energy bills.

High pressure water and steam can produce aerosols that capture bacteria and spread them throughout the plant (and settle on and cross-contaminate clean surfaces long after the cleaning has been completed). This can complicate efforts to effectively clean facilities.

Biofilms are another problem. Biofilms are colonies of bacteria surrounded by a protective layer that firmly attaches them to surfaces and shelters the bacteria from hot water, detergents and sanitizers. It takes a lot of water and pressure to remove biofilms, but they’re very difficult to detect, because they’re invisible. As a result, a lot of hot, pressurized water is used to clean the entire facility, in case biofilms are present.

These researchers plan to investigate ways to reduce cross contamination from aerosols and biofilms using less hot water and pressure, a particular challenge when trying to clean fat from surfaces. Information generated in this work would lead to improved effectiveness of cleaning, reduction in water usage, as well as improved microbiological safety of meat.

Objectives

• Establish an objective measurement of cleaning/sanitation effectiveness and determine cross-contamination potential from aerosols and biofilms,

• Identify conditions to reduce cross contamination, and

• Identify physical/chemical pre-treatments for water to improve cleaning effectiveness of water to reduce the volume and temperature of water used for cleaning.

What they will do

The first two steps will be conducted in a commercial packing facility to establish the baseline of what happens in commercial practice. To quantify cross-contamination from aerosols, they will collect air and conveyor belt surface samples at four points during the cleaning process (before cleaning, after pressure washing, after detergent, after sanitizer) over a three-day period. Bacterial numbers will be counted.

To assess the effectiveness of current cleaning practices against biofilms, BioFinder spray will be used to identify hotspots on noncontact surfaces and the roller mechanisms of conveyor belts, both before and after cleaning. These surfaces will be sampled again before and 20 minutes after sanitization, again over a three-day period. The bacteria present will be identified and assessed for the extracellular polymeric substances that make up biofilms.

The next two steps will be done in a research facility because they are too risky to experiment with in a commercial meat facility. To find out which bacteria form the worst biofilms, they will use 40 bacterial strains previously collected from processing plants. Different strains will be mixed together and incubated with meat juice under varying temperatures for up to six days, and the size and strength of the resulting biofilms will be measured. The biofilms will be exposed to two cleaners (Tergazyme and Powerfoam) and two sanitizers that have been developed for biofilm removal (Decon7 and BioDetect) to test whether they’re effective against multi-species biofilms. The toughest biofilms will be studied further using a ‘confocal laser scanning microscope’ and strategies to combat those biofilms will be evaluated.

Then they’ll test whether different water “preconditioners” like alkali compounds, surfactants, and enzymes to break down fat and protein can help to effectively clean greasy surfaces using less hot water and pressure

Finally, the most effective ways to reduce cross-contamination, biofilms and use cold water will be piloted at the AAFC Lacombe Abattoir and potentially at a commercial facility.

Implications

Finding ways to effectively clean packing plants using less water and energy without sacrificing food safety will support the environmental, economic and social sustainability of Canada’s beef processing sector.