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.

Evaluating Food Safety

One of the suggestions I made in the last blog was to assess the food safety culture in your organization by observing the food handling techniques of workers. Let’s explore that some more. You can do an overall assessment or you can hone in on specific areas of the operation, such as production or cleaning practices. Remember, when the environmental health inspector visits your operation, he/she just gets a snapshot of what is going on in your operation on that particular day at that specific time. You are there nearly every day, so you have a much better understanding on what really happens in your operation.

September is Food Safety Education Month: The Culture of Food Safety

Developing a culture of food safety is important for any foodservice operation. You may be wondering--just what is a culture of food safety? Let’s start talking about it by first defining what is meant by culture. When you look culture up in the dictionary, you will see terms such as shared knowledge, beliefs, values, attitudes, and meanings; a way of life; patterns of behavior; learned behavior of a group of people; and transmitted from generation to generation. I think these descriptors provide good insight into the meaning of a culture of food safety. You can also think about where you grew up, and a vision of culture comes. For example, I grew up in rural Oklahoma, graduating in the 1970’s with a class of 24 students. My culture instilled in me an appreciation for rural life, hard work, and independence. As I grow older, I realize I haven’t changed very much from my early years, even though I have completed a PhD, lived a lot of places, and traveled throughout the world!

Produce Safety: Special Considerations

In our last blog, I talked about general produce safety. Today, I want to talk about some special products—melons, tomatoes, leafy greens, and sprouts. These are all foods that have a history of bacterial contamination leading to foodborne illness. I also want to discuss salad bars because they have some special risks.