Why Does Food Spoil?
Food 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.
Bacteria: 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 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.
Salmonella and Listeria monocytogenes: Serious Threats to the Safety of Food
Earlier in the month, I mentioned the top microbial enemies we all face in foodservice operations, E. coli, Campylobacter, Salmonella, and Listeria monocytogenes. While we discussed E. coli and Campylobacter, we did not get around to discussing Salmonella or Listeria monocytogenes.
E. coli, Campylobacter, Salmonella, and Listeria monocytogenes…oh my!
Last month, I blogged a bit about the human factor in food safety. In the foodservice management realm, I do think the human factor is our biggest challenge, day in, day out. While the human factor is a major contributor to most foodborne illness outbreaks, we can’t forget about the microbial enemy we face on a daily basis.
The Human Factor and Food Safety
A few weeks ago, we discussed the top five causes of foodborne illness, 1) Improper hot/cold holding temperatures of time and temperature control for safety foods; 2) Improper cooking temperatures of food; 3) Dirty and/or contaminated utensils and equipment; 4) Poor employee health and hygiene; and 5) Food from unsafe sources. As I noted, all of these items are not in the direct control of your staff, but most can be. For the second blog this month, I wanted to discuss a bit more about the human factor in our food safety programs.
What is the Greatest Threat to Food Safety?
What is the Greatest Threat to Food Safety?
