News from CRIS: Preservatives & Refrigeration

December 8, 2021

What causes foods to go bad? 

Microbes and oxidation are two significant factors that cause foods to go bad quickly.
Microbes that cause spoiling are undesirable bacteria, fungi, and yeasts that grow in our food products. These microorganisms feed off the foods’ nutrients and can cause serious harm to humans if consumed. Without preservatives, bacteria such as listeria and botulism can invade our foods and, if ingested by humans, can cause us to become critically ill. Less harmful bacteria, fungi, and yeasts will grow on foods making them inedible.
Oxidation, a term for specific chemical reactions, can impact food safety and flavor by causing an undesirable chemical change that can turn fats rancid and cause vegetables and fruits, such as cut potatoes and apples, to brown. Enzymes and other chemical breakdown processes are responsible for the oxidation that transforms foods into unpalatable and, at times, unsafe products.

What do preservatives do?

Preservatives and preservation techniques prevent foods from spoiling and oxidizing quickly, allowing grocery manufacturers to distribute foods across the country and the globe without impacting food safety or quality. 

What are preservation techniques? 

Preservatives are the ingredients and processes we apply to our foods to keep them safe and shelf-stable. There are two key ways we preserve our foods: chemical preservation and physical preservation.

Chemical preservation involves adding specific ingredients to foods and food packaging that allows the food to remain safe and fresh. Humans have been using chemical preservation for thousands of years, and familiar food products such as yogurt, sauerkraut, and kimchi are examples of foods that have undergone chemical preservation.
Physical preservation involves different techniques such as salt curing, refrigeration, smoking, drying, and more to protect food quality. As with chemical preservation, humans have been using physical means to preserve foods since ancient times. One such example is drying and smoking meats, veggies, and more.
These techniques are not mutually exclusive; we often need to use chemical and physical preservation approaches to provide the safest food products with the fewest additional ingredients and processes. Canned foods are a great example of the hybrid preservation approach.


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