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.
Foodborne Illness Myths & Facts
“It must have been something I ate.” That’s the typical statement when a person develops some relatively minor symptoms from food. Maybe not severe enough to go to the doctor so you choose to tough it out without medical care. Sudden onset of flu-like symptoms such as onset of stomach cramps, diarrhea, vomiting and fever could possibly mean you are the victim of a foodborne illness. The illness is sometimes referred to as “food poisoning”, but it’s often misdiagnosed.
Don’t Compromise: Clean and Sanitize
The subject is cleaning and sanitizing. Chefs, food service directors, managers and staff try to practice safe food-handling at every turn in the kitchen. Don’t let that effort go down the drain by slacking off on the many aspects of sanitation. That includes dish and ware-washing techniques (pots, pans, equipment), and cleaning all the areas that give us that “neat as a pin” appearance in your customers eyes. Customers seldom fail to bring that soiled silverware or glass with lipstick on it to the attention of the manager or wait staff. Improperly cleaning and sanitizing of food contact equipment does allow transmission of pathogenic microorganisms to food and ultimately our customer.
The Route to Safer Fresh Fruits and Vegetables
Although fruits and vegetables are one of the healthiest foods sources in our diet, we continue to have foodborne disease outbreaks of significance from produce, sometimes affecting large groups of people in multiple states because of their wide distribution. The CDC estimates that fresh produce now causes a huge number of foodborne illness outbreaks in the United States. Produce needs our continued food safety efforts at the restaurant level as well as at the stages in agricultural production. Occasionally, fresh fruits and vegetables can become contaminated with harmful bacteria or viruses, such as Salmonella, E. coli 0157:H7, Norovirus, and Hepatitis A. This contamination can occur at any point from the field to our table. If eaten, contaminated fruits and vegetables can cause foodborne illness.
Be Cool, Chill Out, Refrigerate Promptly!
The Cold Chain -- Keeping perishable foods at proper cold holding temperatures (between 28°F and 41°F maximum or 0°F for frozen food) from your food producers / manufacturers to your customers has to be one of our strongest links to safe food and high quality. Sometimes that is referred to in the food industry as “maintaining the COLD CHAIN”. Any slip ups in the cold chain, and we have a weak link. Most all of our state food regulations require 41°F as a cold maximum, but colder is a “best practice” policy to maintain.
