Sanitation and cleaning

Creating and maintaining a safe, hygienic food plant is a constant challenge that requires eternal vigilance - one slip up can, potentially, sound the death knell for the business. There is no ‘once and for all’ solution, as the very ingredients themselves frequently carry the bacteria and contamination into the plants. Following are two sets of research you may find interesting.

Tracing Listeria monocytogenes in a commercial chicken cooking plant

Incoming raw poultry is the primary source of Listeria monocytogenes contamination in commercial chicken cooking plants, according to a 21-month study conducted by Agricultural Research Service (ARS) scientists and their collaborators at the University of Georgia.

The study’s results will help these facilities more sharply focus their sanitation processes to reduce cross-contamination. L. monocytogenes is a bacterial human pathogen that is sometimes found in fully cooked, ready-to-eat processed meat and poultry products.

By testing a brand-new commercial cooking facility before and after processing began, the research team was able to track sources of contamination. The research team was led by ARS microbiologist Mark Berrang of the Bacterial Epidemiology and Antimicrobial Resistance Research Unit at the agency’s Richard B Russell Research Center in Athens, Ga.

Because the pathogen is prevalent in the environment and in various forms, there were several potential sources of contamination, including employees, incoming fresh air, raw meat and the surrounding environment.

Potential sources of L. monocytogenes were tested by taking samples of soil and water around and near the facility exterior and by testing heavily travelled floor surfaces following personnel shift changes. Samples were also collected and tested from incoming air from air vent filters and from monthly swabs of incoming raw meat. The plant was free of L. monocytogenes when first constructed; floor drains in the facility were sampled approximately monthly to determine at what point the plant would become colonised with the bacteria.

Within four months of operation, L. monocytogenes was detected in floor drains, indicating that the organism had been introduced from some outside source. No L. monocytogenes was recovered from any floor samples in the plant entryways, locker room or cafeteria. Likewise, the organism was not detected on air vent filters during the survey. The only tested source found to be consistently positive for L. monocytogenes was incoming raw poultry meat.

Quality assurance in the test plant was exceptional and included an extensive proactive sampling plan to assure food safety. L. monocytogenes can become prevalent in food processing environments; sanitation, biosafety and product sampling protocols are in place in these facilities to prevent shipping contaminated product.

Risk management by hygienic design and efficient sanitation programs

Hygiene in food processing factories is highly dependent on hygienic design of the process lines and equipment, as well as on cleaning efficiency. Principles of hygiene design are simple but several faults appear in food processing premises.

Hygienically designed process lines are supposed to be cleanable but, still, optimisation of cleaning programs is worthwhile. Cleaning of complex equipment is very challenging. Choosing suitable cleaning agents and disinfectants for various food processing equipment and process environment requires knowledge about efficacy of chemicals and properties of surface materials. It is important to apply the knowledge of good cleaning practices in everyday cleaning routines in food factories and improve sanitation programs constantly.

A seminar on risk management by hygienic design and efficient sanitation programs was held in Tallinn (Estonia) last May. This final seminar of SAFOODNET EU-project (Food Safety and Hygiene Networking within New Member States and Associated Candidate Countries; FP6-022808-2006) provided information about hygienic design and cleaning procedures and concluded the pilot case studies performed during this three-year-project. Participants were challenged to create risk management plans for different imaginary factories using all the knowledge gained in the workshops and seminars of the project. These groupworks interactively summarised the lectures and, more importantly, built firm networks between group participants. The groupworks, as well as participant abstracts on risk management, have been published by the Technical Research Centre of Finland (VTT). ‘Risk Management by Hygienic Design and Efficient Sanitation Programs’ edited by Gun Wirtanen and Satu Salo can be found at http://www.vtt.fi/inf/pdf/symposiums/2009/S261.pdf.