Temperature Control Of Potentially Hazardous Foods

Some categories of food are more likely to have microbial reproduction due to intrinsic and extrinsic factors. According to the FDA Food Code, potentially hazardous food refers to natural or synthetic foods that require temperature control because they tend to have the following.

     1) rapid and progressive growth of infectious or toxigenix microorganisms

     2) growth and toxin production of Clostridium botulinum

     3) growth of Salmonella Enteritidis (in shell eggs)

Foods that fall into this description include meat, poultry, seafood, eggs, cooked rice, raw seed sprouts, cut melons, garlic and oil mixtures, etc.
Due to their varied natures and components, different kinds of food need to be kept in specific environments. The FDA demands constant temperature monitoring to ensure that foods are stored within the safe zone.

Food suppliers should also be aware that food processing also influences the microbial level in the foods. Washing fruits and vegetables with chlorinated water would lower the bacteria levels but would not necessarily eliminate pathogens. Freezing practices can slow down the microbial reproductions, but do not affect the pathogen level. Cooking, fermenting and smoking can restrict the majority of bacterial flora, and the low pH level in pickled products inhibits the growth of most bacteria. Meanwhile, improper handling and packaging may introduce microorganisms into the food during the handling process.

Meat and Poultry

Raw meat and poultry usually have a higher water activity level and a neutral pH level—the optimum combination for bacterial growth. When meat is cooked or processed followed by refrigeration, the bacteria level in meat and poultry greatly reduces, yet environmental post-processing pathogen contamination might still occur.

FDA recommendations on time/temperature control:
“Unless the specific product parameters referenced in the previous section are met, meat and poultry products must be considered as requiring time/temperature control. Raw meat and poultry products currently require safe-handling instruction labeling that includes a time/temperature control provision. For ready-to-eat foods, product parameters and processing schedules are needed to ascertain whether temperature control for safety is required. Post-processing contamination is also an important consideration and should not be overlooked. Because meat offers a rich nutrient media for microbial growth, products that incorporate meat and poultry as ingredients, such as meat salads and meat pastries, also must be considered as requiring time/temperature control.”

Fish and Seafood Products

The high level of soluble nitrogen compounds found in seafood makes it more perishable than other high-protein products. Since seafood is usually harvested from the wild, it’s also exposed to environmental contaminants and pathogens. Mishandling during or after processing is a main cause of foodborne illness from seafood.

FDA recommendations on time/temperature control:
“Most seafood, including cooked seafood and sushi, requires time/temperature control. Only fully retorted or fully dried and salted products are considered shelf stable. Most smoked seafood products require time/temperature control because of the concern with C. botulinum growth and toxin production, in addition to their being highly perishable. Heavily smoked products with low water activities are spoiled primarily by molds.”

Fruits and Vegetables

With fruits, the initial bacteria level is usually comparatively low. Fruits and vegetables do not have as many issues with pathogens, but yeasts and molds are more prevalent due to fruits’ low pH level. There is a lot of concern with fresh-cut products: the process breaks the natural protective barriers, causing increased pathogen multiplication, adequate moisture, abusive temperature and sufficient time will allow bacteria population to increase exponentially.

FDA recommendations on time/temperature control:
“Strategies to reduce microbial hazards in produce include the implementation of Good Agricultural Practices on farms, and Good Manufacturing Practices (GMP) in packing, handling and storage. Due to their highly perishable nature, most fresh fruits and vegetables need time/temperature control to extend their shelf life. In any case, attention should be paid to storage times and temperatures since pathogens, if present, are able to grow- particularly in the case of fresh-cut produce or where internalization is possible. Storage temperature and time management are important in reducing the risks of foodborne illness, and become critical parameters for any fresh-cut produce. However, as mentioned above, the time/temperature for seed sprouts will not reduce the risk of presence of high levels of pathogens. While, traditional processing methods such as freezing, canning, dehydration, fermentation and acidification are used to improve the stability of fruits and vegetables, and time/temperature control may not be a requirement for these processed products.”

Egg and Egg Products

Despite their natural antimicrobial barriers, eggs can still be contaminated by trans-shell and trans-ovarian infections. Heat treatment does not guarantee the products to be shelf-stable or safe.

FDA recommendations on time/temperature control:
“Eggs and egg products will easily support the growth of spoilage and pathogenic microorganisms and clearly require time/temperature control to assure safety. Control methods require an integrated approach that begins at the egg production facility and carries through to processing and further processing operations as well as to retail and food service facilities. Temperature control of shell eggs, followed by thorough cooking and proper handling, are essential in assuring safety. As mentioned above, heat treatments used for liquid eggs do not produce shelf-stable products, so they should be kept refrigerated or frozen. These products should be safely handled to reduce the likelihood of post-process and/or cross contamination.”

Milk and Milk Products

Milk provides adequate nutrients for microbes, has a neutral pH level, and is high in moisture. Subject to microbial spoilage, it will quickly become unacceptable for human consumption if sanitary practices and temperature control during handling are not conducted properly.

FDA recommendations on time/temperature control:
“During handling, basic sanitary practices and temperature control are required to maintain acceptable sensory qualities of milk and milk products. Similarly, most milk and milk products are sold refrigerated to prevent spoilage. Exceptions include canned milks, dried milk, ice cream, aseptically processed and packaged products, and thermally processed products that are packaged hot in conjunction with specific product formulations. These milk products do not require refrigeration because of the combination of moisture content, salts, and pH that control the growth of microbes.”

Overall, the following categories of food require close temperature control to prevent spoilage and to extend their shelf life: meat and poultry, most seafood (including cooked seafood and sushi), eggs, and most fresh fruits and vegetables. Dairy goods and cooked egg products need to be refrigerated before consumption. Fully salted and dried seafood products, as well as acidified fruits and vegetables are shelf stable thus not requiring stringent temperature monitoring.