Why Does Food Spoil?

bagsFood gradually deteriorates because of a natural process of aging, just like humans. However with all foods, there are a few things we can do that have a positive effect on the shelf life and safety of our foods at the restaurant. Some preservation is done at the food manufacturing plant, some naturally, but a better understanding of the processes may help you extend that shelf life. Preservation methods and storage conditions must be designed to reduce the rate of decomposition and protect the safety, appearance and taste of our food.

The causes of food spoilage – Plant and animal tissue starts to decay soon after raw food has been harvested or killed. The spoilage process is usually caused by microorganisms such as fungi (molds & yeasts), spoilage bacteria, and their enzymes. Not all these changes in food are undesirable.  Some people like aged beef and cheeses or very ripe fruit. The production of wine and beer involves conversion of sugars to alcohol, while souring of milk is essential in the production of cheese.

However, it’s important to remember that some of the conditions that accelerate spoilage, such as inappropriate temperature and moisture control, also encourage the growth of pathogenic microorganisms that cause foodborne illness. Consequently, spoiled food is not just an issue of quality, it is also often a question of food safety.

Mold & Yeast:  Corn, nuts, breads, meat, cheeses, fruits and vegetables are affected by mold. With  most cheeses (i.e. cheddar, mozzarella, American, or Swiss), don’t try to salvage cheese that shows visible mold by cutting it away unless it’s a natural part of the cheese like bleu cheese, Brie, or Camembert.  Mold forms a network of microscopic strands that extend into the foods which could cause allergic reactions or illness, so discard them. Most cheeses don’t improve with age. Deli meats are the same. Yeast can cause discoloration, slime, and odors on sweet, acidic refrigerated foods or jams/jellies.

bags 2Bacteria:  Some spoilage bacteria are also pathogenic (disease causing). For example, Clostridium perfringens (a common cause of spoilage in meat & poultry) and Bacillus cereus (spoils milk & cream) are also responsible for causing foodborne disease. Most foods are subject to bacterial growth.

Enzymes:  They are naturally present in the cells of microorganisms that break down animal and plant foods. Breakdown continues until the enzymes are inactivated by blanching or cooking.

Other causes of spoilage include: 1) bruising or piercing because of rough handling such as vegetables, fruits or vacuum packaged food; 2) oxidation (changes the taste or texture when exposed to oxygen) or freezer burn; 3) pest infestation because of poor receiving control, storage, rotation or cleaning; 4) adulteration by addition of leftover food to fresh food, inferior or undesirable food or ingredients.

Detecting spoilage includes the typical indicators such as appearance (discoloration or slime), texture, smell or taste (obviously not recommended if any of the others are present).

Bottom line – When in doubt, throw it out. Food spoilage does affect your bottom line in food waste dollars, so prevention includes good receiving inspection practices, following manufacturer’s instructions, utilizing innovative active packaging or food storage bags, unfailing temperature recording and control, being observant and certainly good sanitation and personal hygiene by food handlers. 

 

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About the Author: Lacie Thrall

Lacie Thrall PictureLacie Thrall passed away in early 2017 after a long illness. She dedicated her 35-year career to improving the health and well-being of others by promoting food safety best practices. Lacie worked in environmental health for 17 years before joining FoodHandler in 1997 as the Director of Safety Management. While at FoodHandler, she trained employees and customers on safe food handling practices, including proper hand hygiene and glove use. Later as a FoodHandler consultant, Lacie provided the foodservice industry with food safety information and advice through her blog on FoodHandler.com.

Meat Color and Doneness: Persistent Pinking

Late in June, my family and I were able to visit the Black Hills, an area of the country in which I have not had the opportunity to spend much time.  One evening, as we dined at a local restaurant, I observed a table across the dining room sending back a dinner.  While I couldn’t hear the entire conversation and I certainly wasn’t trying to eavesdrop, it was apparent that the customer was unhappy with the cooking of their hamburger and was sending it back because it was too pink in the middle.  That immediately brought to my mind the phenomenon known as persistent pinking.  A term I became familiar with because of work done by some colleagues here at Kansas State, which they present each summer to a group of foodservice operators who join us on-campus for an in-depth week-long look at all things food safety.

Quat Binding – Why this Can Have a Disastrous Impact on Your Sanitation Program.

In June, I had the opportunity to represent FoodHandler and speak on food safety behavior for customers of Martin Bros. Distributing in Waterloo, Iowa.  One of the questions that was asked caught me a little off guard. The question was about quat binding.  It caught me off guard not because it was a bad question, but only because it was not something I had previously been asked nor had not yet been exposed to the phenomenon. However, I soon learned that in certain jurisdictions, it is resulting in changes to how sanitizing cloths are to be stored in sanitizing buckets (or not) in the foodservice industry. When I returned home from the trip, I had to dig into it to learn about what quat binding is and how it might impact foodservice operations.

Are Grades for Foodservice Inspections a Good Idea?

I generally try to stay away from controversial topics in my blog, but this is one I thought it might be interesting to discuss. Occasionally on my travels, I will come across a state or a local jurisdiction that requires foodservice inspection scores be posted in the window of the establishment.  The idea is to allow would-be customers the ability to see how the foodservice operation in which they are about to eat scored on their latest health inspection.