Tag Archives: bacteria

Support Your Food Safety Program with Environmental Testing Solutions

At Nelson-Jameson, we never take chances when it comes to food safety, and neither should you. That’s why we’ve put together a comprehensive flyer that is filled with the products you need to create an effective food safety program in your plant. Even more promising than the quality products is the manufacturers that are represented—we’ve included top products from 3M™, Hygiena™, Nasco, and Neogen®. Let us help you implement the Environmental Testing Solutions that work for your plant.

For more information on environmental testing, visit our Learning Center, or request a copy of our Environmental Testing Flyer here.

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Heterofermentative Spores in Milk and the Resulting Quality Issues

In recent months, it has come to our attention that there has been an increase in quality problems caused by Heterofermentative lactic bacteria that are not from starter cultures. These bacteria have been found growing on biofilms in the pasteurizer regen section of milk HTST’s, in some silage inoculants, in dairy powders and liquids used to fortify milk for cheesemaking, and on individual farms with certain cleaning issues. Once these are in the milk, they can’t be removed by pasteurization and will carry through into the cheese and whey powder by-products.

The Center for Dairy Research (CDR) in Madison has seen an increase in quality defects in cheese including off flavors such as “sour” gas formation in retail packages of cheese and cracking defects in blocks of cheese. Many companies are starting to include specifications for low spore count non-fat powders, liquid condensed skim and UF milk products, and also whey powders used in many other foods. There is also evidence of excess viscosity of buttermilk and sour cream from this contaminant.

What can the cheesemaker do to solve these issues?

  • While there is no substitute for good cleaning and sanitation, there are tests available for these contaminants such as 3M’s Lactic Acid Petrifilm. Petrifilm can be used to test milk from the regen section of the HTST, screen milk loads from the farm, and test finished whey products. We have some plants already trying to locate sources of these spores by using Petrifilm.
  • We have at least one DSM cheese culture being used to improve cheese flavors, especially in aged Cheddars. This culture is referred to as RF-4 from DSM. The culture is added to the cheese vat milk and competes with other contaminants to impede their multiplication and the off flavors and possibly gas that result from them.
  • Eliminate biofilms in all milk handling equipment either at the plant or on the farm. We sell both 3M (LM1) and Hygiena (EnSURE & SystemSURE PLUS) ATP Luminometers that verify cleaning processes by the use of bioluminescence technology, and provide the customer with a numerical value to determine their cleaning effectiveness on food contact surfaces.
  • There is some research that suggests certain silage inoculants can carry through into the milk supply. The CDR is still looking at this potential source.
  • Ask for help and advice. We have a variety of industry people we can contact to visit the plants and farms to help troubleshoot.

Contact one of our Product Specialists today for additional information!

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Foodborne Bacteria: Do You Know How They Grow?

Food safety concerns are on all food manufacturers’ minds (and, honestly, probably in their dreams too), so it is critical to know how bacteria grow.  Armed with that knowledge, we are better able to stay ahead of bacterial contamination in the food manufacturing facilities.

Petri dish with bacteria.

Petri dish with bacteria. Source: processingmagazine.com

Often, when I was in the plant environment, I would refer back to a case study put together by the Royal Society for Public Health in 2010. It laid out some excellent basics on growth factors for bacteria in a concise manner that readers of The Wide Line may appreciate.

The RSPH states, “In order to grow, bacteria require a source of nutrients, an appropriate atmosphere, neutral or alkaline conditions, available moisture and an appropriate temperature. (In turn), the nutrient source needs to have available moisture, a source of energy, nitrogen, vitamins, and minerals.” A large number of bacteria are able to grow with or without oxygen. Some bacteria (obligate aerobes), will only grow if oxygen is present. Other bacteria (obligate anaerobes) will only grow in the absence of oxygen.

The RSPH’s “Growth Requirements of Bacteria” section continues: “Most bacteria grow best in a neutral or alkaline environment. Bacteria do not grow well in foods which are too acidic (with a pH of less than 4.5).”  So, the more acidic the food, the less likely it is to support the growth of bacteria.  In addition, foods that are dried or high in salt or sugar have a reduction in available moisture content, and bacteria will grow poorly on these foods.

Finally, “Most bacteria will not grow in cold conditions, or will only grow and divide slowly. High temperatures will also inhibit the growth of bacteria.”  For example, most food poisoning bacteria die when exposed to a temperature of 70°C for two minutes or more. The optimum temperature range for the growth of most bacteria is 5°C to 63°C, which is known as the ‘temperature danger zone’.

The RSPH concisely acknowledges that there are multiple areas in all food production facilities that need to be assessed for risk regularly, as well as monitored daily in order to prevent microbiological product contamination. All processing steps have the potential to increase the chance of microbial corruption.  Nelson-Jameson carries food safety products that assist with control and surveillance in every step of the production process—from ingredient receiving through manufacturing, storage, and shipping of finished products.  Contact a sales representative today to find out how Nelson-Jameson can help strengthen your food safety prevention and protocol.

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Testing the Water

j0444789What is the difference between water activity and water “moisture” content? Well, it all depends on what you want to achieve. Do you want to monitor the amount of water and dry matter present in a product? Or do you want to increase and monitor the shelf stability of a product?

“Water ‘moisture’ content is the amount of water contained in a product”. Measuring water “moisture” content is better used to determine quality of the process. For example, if the product is a cheese powder that is spray dried, it is common practice to measure the water “moisture” content to determine yield and to ascertain if your drying process is running according to the diagnosed plan.

Water activity is defined as the measurement of the availability of free water for biological reactions—especially the biological reactions that can make humans and animals very sick.  Water activity is more critical in the food industry. Bacteria love water; gram-negative bacteria like E.coli need a minimum of .97 moisture content for growth, and the Staphylococcal toxin produced by Staphylococcus aureus only needs a minimum of .93 for growth. To put this into perspective, know that pure water’s moisture content is 1.00. Thus, it is critical for food manufacturers to know and monitor the water activity before, during, and after manufacturing for safety. See the table below for the water activity and content levels of common foods:

Water Activity of Common Foods (aw)

fresh meats and fish:                     0.99

moist cakes:                                       0.90-0.95

soy sauce:                                           0.80

jams, marmalades, jellies:            0.75-0.80

dried spices, milk powder:           0.20-0.60

Water Content of Common Foods (%)

apples:                 84

peppers:              92

salami, beef       60

dried fruit            31

wheat flour        11

Water activity is crucial to food safety. Microbes are everywhere, and will find any way possible to a food source, ultimately causing spoilage. Moisture analysis monitoring processes are set up to eliminate as many microbes as possible, with the key to moisture control and water activity being to find ways to bind the water so that it doesn’t allow microbes to find a food source—thus extending a product’s shelf life. Contact one of Nelson Jameson’s product specialists today to discuss your moisture analysis and water activity needs.

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Water Savings and Effective Cleaning? Full Steam Ahead!

steam cleanerSteam: this is not really a topic most would like to think about as the temperature climbs. However, it is a topic you may want to take note of though for the next few moments, as it could affect your bottom line this summer and beyond. Steam cleaning is a powerful method used to combat germs and to sanitize surfaces in domestic, commercial, and industrial spaces.

For food operations, there are several key aspects of steam cleaning that are ideal for industrial settings. First, steam cleaning is effective; it kills germs and bacteria. It also attacks grease and cleans surfaces thoroughly. Second, it is cost-effective. Using steam means less chemicals in your plant and it means merely adding water to your steam cleaner to effectively get the job done. Third, the right steam cleaner can reduce your manual labor costs.

If you would like to know more about steam cleaners, and even some currently available close-out specials for your operation and for information on the potential uses and efficacy of steam cleaners, contact our Processing & Flow Control Department at 800-826-8302.

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