Bacteria in Food and How Do They Affect Your Health

by Joost Nusselder | Last Updated:  June 2, 2022

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Bacteria are ubiquitous and can be found in various places such as homes, gardens, and food. Their presence can be attributed to various factors such as purchasing, preparation, and consumption.

In this article, I will explore the different types of bacteria present in food and provide tips on how to prevent illness caused by them.

What are bacteria

The Fascinating World of Microbiology in Food Processing

Thermal processing involves heating foods to a specific temperature to reduce or eliminate microorganisms that cause spoilage and disease. Heating can also enhance the stability and shelf life of foods. The thermal resistance of microorganisms varies according to their characteristics and composition. Adequate heating can reduce losses due to spoilage and increase the safety of foods. Pasteurization is a common technique used in the food industry to reduce the number of microorganisms and ensure hygienic conditions.

Strategies for Reducing Microbial Contamination

Efforts to reduce microbial contamination involve various strategies, including good hygiene practices, traceability, and delay in distribution. The use of hygienic practices in food processing and retail industries can reduce the risk of contamination. Traceability involves tracking the movement of food products from manufacture to retail. Delay in distribution can reduce the risk of unsafe foods reaching consumers. The implementation of these strategies can substantially reduce the prevalence of foodborne diseases and improve food safety.

What You Need to Know About Common Bacteria in Food

  • Salmonella, E. coli, shigella, Bacillus cereus, listeria, and campylobacter are the main types of bacteria found in food.
  • These bacteria are more likely to affect children, senior adults, and those with compromised immune systems.

The Foods That Commonly Carry Bacteria

  • Certain foods are more prone to bacteria growth and production, such as meat, rice, and fresh produce.
  • Water can also be a source of bacteria, especially if it is untreated or contaminated.
  • Milk and milk products can also be a breeding ground for bacteria, especially if they are not processed properly.

The Ability of Bacteria to Survive and Form Toxins

  • Bacteria have the ability to resist and prefer certain temperatures, pH levels, and environments that enable them to survive and produce toxins.
  • Bacillus cereus, for example, can produce emetic and diarrheal syndromes through the formation of toxins.
  • Salmonella, on the other hand, is a pathogenic bacteria that can cause foodborne illness characterized by symptoms such as nausea, vomiting, and diarrhoea.

The Importance of Cooking and Processing

  • Cooking and processing of food products are required to limit the growth of bacteria and prevent food poisoning.
  • Different kinds of bacteria have different temperature ranges for growth, with a minimum of approximately 4°C for vegetative cells and 12°C for spores.
  • Fried foods, for example, can be a source of toxin formation caused by Clostridium perfringens, which has an onset time of 8-22 hours after consumption.

The Final Point

  • The presence of bacteria in food is natural, but it can have serious consequences if left untreated or uncontrolled.
  • The data shows that millions of cases of foodborne illness occur each year, depending on the variety of bacteria and the foods they affect.
  • It is important to be aware of the risks associated with common bacteria in food and take necessary precautions to prevent contamination and illness.

Temperature: The Critical Factor in Bacteria Growth Control

Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the “Danger Zone.” The growth of bacteria is controlled by temperature, pH, and water activity. Temperature is the most critical factor in controlling bacteria growth in food.

The Importance of Temperature Control in Cooking

Cooking is the process of using heat to kill bacteria in food. The internal temperature of beef, poultry (try these woods to smoke it), and fish must reach a sufficient temperature to kill any bacteria present. The minimum safe temperature requirements for different types of food are as follows:

  • Ground meat: 160°F
  • Beef, pork, lamb, and veal (steaks, roasts, and chops): 145°F (rare), 160°F (medium), and 170°F (well done)
  • Poultry: 165°F
  • Fish: 145°F

The Role of Holding Temperature in Bacteria Growth Control

Holding temperature is the temperature at which cooked food is held before being served. It is critical to hold food at a safe temperature to prevent the growth of bacteria. The safe holding temperature for hot foods is 140°F or above, while cold foods should be held at 40°F or below.

The Importance of Scheduling and Continuous Monitoring

To ensure that food is held at a safe temperature, it is important to schedule and continuously monitor the holding temperature. This can be achieved by using a thermometer (best for smokers reviewed here) to check the temperature of the food at regular intervals.

The Importance of Combinations of Microbial Lethality Regimens

Combinations of microbial lethality regimens, such as temperature and pH, can be used to achieve microbial lethality in food. For example, a combination of heat and acid can be used to achieve a reduction in bacteria growth.

Indicator organisms are microorganisms that are used to determine the likelihood of pathogenic and spoilage organisms being present in food. These organisms do not cause disease themselves, but their presence indicates that other harmful bacteria may exist in the food or environment.

The Unpleasant Side of Bacteria: Signs of Food Spoilage

Spoilage is a natural process that occurs when bacteria, fungi, or other microorganisms break down the fresh food item. This decomposition process can make the food item softer, change its appearance, and produce an unpleasant odor or taste.

Visible Signs of Spoilage

There are different visible signs that indicate food spoilage. Here are some of the most common ones:

  • Mold: Mold is a visible sign of spoilage. It appears as a fuzzy or slimy growth on the surface of the food item.
  • Discoloration: Discoloration is another sign of spoilage. Fresh food items have a vibrant color, but when they start to spoil, they may turn brown, gray, or green.
  • Texture: Spoilage can make the food item softer or mushy.
  • Odor: Spoiled food has an unpleasant odor that is different from its fresh smell.

Human Perception of Spoilage

Spoilage is not always visible or externally noticeable. Sometimes, the food item may look and smell fine, but it can still be spoiled. This is because humans have different thresholds for detecting spoilage. Here are some examples:

  • Bitterness: Some people are more sensitive to bitterness than others. A food item that tastes fine to one person may taste bitter to another, indicating spoilage.
  • Off-flavor: An off-flavor is a taste that is different from the food item’s natural flavor. It can indicate spoilage, but some people may not notice it.

Undesirable Effects of Spoilage

Spoilage can have unpleasant effects on the human body. Here are some examples:

  • Food Poisoning: Certain bacteria produce toxins that can cause food poisoning. Symptoms include nausea, vomiting, diarrhea, and fever.
  • Allergic Reactions: Mold can trigger allergic reactions in some people, leading to respiratory problems, skin rashes, and other symptoms.

In conclusion, it’s essential to be aware of the signs of spoilage to avoid consuming spoiled food items. Remember, when in doubt, throw it out!

Don’t Let Bacteria Ruin Your Meal: Understanding Food Poisoning

Food poisoning is an illness caused by consuming contaminated food or water. It occurs when harmful bacteria, viruses, or parasites grow and multiply in food, making it unsafe to eat. The symptoms of food poisoning can range from mild to severe and can include nausea, vomiting, diarrhea, fever, and abdominal pain. In some cases, food poisoning can be life-threatening, especially for young children, pregnant women, and people with weakened immune systems.

How to Prevent Food Poisoning

Preventing food poisoning requires proper handling and preparation of food. Here are some essential tips to help prevent food poisoning:

  • Wash your hands and utensils before and after handling food.
  • Cook food to the right temperature. Use a food thermometer to make sure that meat, poultry, and fish are cooked to the proper temperature.
  • Cut meat and poultry properly. Use a separate cutting board for raw meat and poultry to avoid cross-contamination.
  • Avoid eating raw or undercooked meat, poultry, fish, and eggs.
  • Refrigerate or freeze perishable foods within two hours of purchase or preparation.
  • Thaw frozen food in the refrigerator, not on the counter.
  • Don’t leave food out at room temperature for more than two hours.
  • Use good water sources for drinking and cooking.


So, bacteria are tiny organisms that can make you sick. They can be found in food, especially in raw foods like meat and vegetables. 

The most important thing to remember is to cook food properly and keep it cold so that bacteria don’t grow. So, make sure you know the signs of food poisoning and don’t forget to wash your hands!

Joost Nusselder, the founder of Lakeside Smokers is a content marketer, dad and loves trying out new food with BBQ Smoking (& Japanese food!) at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.