Bacteria and Food-borne DiseasesRichard Massey Types of Bacteria Bacteria are all around us, in the air, water, ground, on our skin and in our bodies. They are classified in a variety of ways, but for our purpose we can categorize them in a more basic way. Harmless bacteria – Most bacteria fall into this category. They are neither help us nor are harmful to us. These bacteria have a specific purpose, but are not a concerning to us in terms of food safety, Beneficial bacteria – Believe it or not some bacteria are helpful to us. Some bacteria are used in foods to make cheeses and yogurts. And still others live in our bodies to fight of harmful bacteria. Undesirable bacteria – Undesirable bacteria is responsible for food spoilage. This type of bacteria may not make you sick, but they show themselves by the use of odors, sticky or slimy surfaces and discoloration. Illness causing bacteria or pathogens – These are the bacteria that cause most food-borne illnesses. Pathogens do not necessarily leave detectable odors or taste in food. This makes it impossible to tell if food is contaminated by smelling or tasting, or looking at it. The only way to protect yourself from this bacteria is by proper food handling and sanitation. Bacteria Growth Bacteria simply multiply by splitting in half. Under the ideal conditions, they can double in number every 15 to 30 minutes. This means that one single bacterium could multiply to a million in less than 6 hours. What do bacteria need to multiply Food – Some from of food is a basic requirement for bacteria to grow. Moisture – Water is required for bacteria in order to absorb food. Dry foods will not support bacterial growth. As well, foods with very high salt or sugar content make bacteria unable to use the moisture present. Temperature – Bacteria grow best at warm temperatures between 40 and 140°F. This temperature range is what we call the food danger zone. Air – Most bacteria require oxygen to grow, but not all. There are some exceptions, one type of bacteria being botulism. Time – When bacteria are introduced to a new environment, they need time to adjust before they start to grow. This time is called the lag phase and last about one hour. How is bacteria transferred Bacteria are carried from one place to another by being carried. This can happened by peoples hands, coughs, other food, utensils, equipment, water, or pests. Preventing Bacteria Growth Now that we know how bacteria grow and are spread; we should be able to prevent food-borne illness by following three simple steps. 1. Keep bacteria from spreading by not letting anything that might contain bacteria tough the food. This includes people, dirty equipment, utensils and possibly other foods. 2. Stop bacteria from growing by taking away the conditions that encourage growth. The most effective way is to keep food out of the danger zone. Keep foods below 40°F and about 140°F 3. Finally kill the bacteria. Most bacteria are killed if they are subject to a temperature above 165°F for 30 seconds. This is how we make food safe by cooking. This heat is also how we sanitize dishes and equipment. Certain chemicals such as bleach also kill bacteria. Using sanitizing agents is best way to sanitize counter tops and large equipment.
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