Food Microbiology: How to Become a Quality Control Freak

Quality control in the food industry has a multitude of meanings. But the basic principal—to ensure sufficient quality—always remains the same.

In today’s market, a company’s reputation rests on the quality of its products. When describing the Coca-Cola Co. in his book Economics: Private and Public Choice, 12th Edition, James Gwartney, PhD, explains, “The value of that brand name is a hostage to quality control. The firm would suffer enormous damage if it failed to maintain the quality of its products.” History shows that companies that have issued product recalls not only endure financial crisis but often struggle to regain customer confidence.

The food industry is experiencing an alarming number of major product recalls due to microbial contamination. In recent years, food safety has become a global concern affecting public health, economics, and international trade. As a result, we are now seeing stronger government oversight with the FDA Food Safety Modernization Act (FSMA) signed into law on Jan. 4. Much of the new law is focused on prevention of contamination in the food supply. Food processors of all types will be required to establish, implement, and monitor comprehensive prevention-based food safety systems, as well as maintain plans for corrective actions when necessary. The FSMA also authorizes the FDA to execute risk-based inspections of food processing facilities and, when necessary, to enforce mandatory recalls of all food products.

Meanwhile, controlling foodborne pathogens has become more complex than ever, with the existence of antibiotic-resistant pathogens and potential adaptation or resistance to traditional food preservation barriers such as acidity, thermal processing, cold temperature storage, dry or low-water-activity environments, and chemical additives. Add into the mix the constant introduction of new rapid test methods and specialized equipment for microbial detection, along with continuously evolving regulatory requirements and standards, and a company can quickly become overwhelmed by the task of keeping up with the demands of this ever-changing industry.

Developing and implementing a sound quality-control program is integral to maintaining quality standards and meeting regulatory requirements. When it comes to food safety, being a quality control freak is never a bad thing.

Assurance vs. Control

Quality assurance is the comprehensive program designed to ensure that production and laboratory processes are held to a minimum standard of quality. This maximizes the probability that the products made by the production process and the results obtained in the laboratory will be correct and of the highest quality.

Quality control of testing is the inclusion of entities of known characteristics with each test run to monitor the quality of the testing process in order to ensure that the results of each test are accurate and reliable. After all, what good is testing if you don’t know that it works? Continuous quality control of tests can help to identify problem areas such as degraded media or reagents, malfunctioning equipment, or improper training of technicians.

For example, using microorganisms of known phenotypic properties alongside an unknown sample helps to ensure that a selective medium supports growth of specific species of organisms and not of others. Without this in-process check, there would be no way to distinguish between situations in which there are no microorganisms in a sample and those in which the media in question cannot support growth.

Microbiological testing methods that should be quality control tested include:

Presence/absence testing: Foods are routinely tested to establish the presence or absence of specific pathogens or toxins. In some cases, the microorganism count may be too low to be detected by enumeration methods, or the microorganisms may be injured by food processing methods, preventing growth on a selective media. It is not uncommon for target microorganisms to be present at levels of only one cell per 100 g of food product. In such cases, enrichment techniques may be necessary.