What Is a Safe Food Supply?

Although today’s food supply is much safer than it was 100 years ago, outbreaks of foodborne illness still occur. One well-known example was the Chipotle Mexican Grill outbreak, in which nearly 1,100 people became ill after eating contaminated food. According to a report from the U.S. Food and Drug Administration (FDA), the outbreak was caused by improper food handling.

From approximately 2015 to 2018, Chipotle faced at least five food safety incidents at various restaurants around the country, which stemmed primarily from store-level employees’ failure to follow Chipotle’s food safety policies and procedures, including the policy requiring the exclusion of restaurant employees who were sick or recently had been sick, as well as a failure by restaurant employees to hold food at appropriate temperatures to prevent and control for the growth of foodborne pathogens. ^[1]

The culprits were E. coli in the 2015 outbreaks and Clostridium perfringens in 2018.  Both bacteria are easily transferred to food by sick food handlers; they proliferate when foods are held at room temperature. In 2020, Chipotle agreed to pay a $25 million fine to resolve charges stemming from the outbreaks. The fine prompted the restaurant chain to improve its employee food-safety training program.

Although the Chipotle incident and illnesses that resulted put doubt in many people’s faith in restaurants, the number of people affected is just a fraction of the 48 million foodborne illnesses that occur each year.

Probiotics: HEALTHY BACTERIA 

Probiotics and prebiotics are widely discussed in the media because of their role in supporting gut health.

Probiotics are live microorganisms that provide health benefits when consumed in adequate amounts. They are often called “friendly bacteria” because they help maintain a healthy balance of microbes in the digestive system. The most common probiotics are lactic acid bacteria, such as Lactobacillus, which are found in fermented foods like yogurt.

Prebiotics are nondigestible food components, primarily certain types of soluble fiber, that feed beneficial bacteria in the large intestine. By promoting the growth and activity of these microbes, prebiotics improve gut health.

Research on probiotics and prebiotics is ongoing. As scientific evidence continues to grow, clearer recommendations about effective doses, specific strains, and health benefits are expected. ^[2]

The Government’s Role in the Food Supply

Thanks to government oversight, the U.S. food supply is closely monitored to protect public health. Foods and beverages served in school cafeterias, restaurants, and grocery stores are subject to strict federal and state regulations. Food processing plants often have on-site inspectors who ensure that safe food-handling practices comply with established guidelines.

If you have ever worked in a restaurant, you may remember surprise visits from health department inspectors who check food temperatures, verify that refrigerators and freezers contain thermometers, and confirm that sanitation standards are followed. The next time you dine out, look for the restaurant’s inspection form—usually posted near the entrance—with a numeric health score. In Tennessee, you can even view restaurant inspection scores online to see how well your favorite spots measure up.

Internationally, the Food and Agriculture Organization (FAO) of the United Nations has similar global programs to promote food safety worldwide. They describe the process as:

Keeping food safe is a complex process that starts on the farm and ends with the consumer. FAO is the only international organization overseeing all aspects of the food chain, thereby providing a unique, 360° vision on food safety. A longstanding partnership with the World Health Organization (WHO) enhances this perspective.

Through complementary mandates, FAO and WHO cover a range of issues to support global food safety and protect consumers’ health. WHO typically oversees and maintains strong relationships with the public health sector, and FAO generally addresses food safety issues along the food production chain.^[3]

If governments monitor our global food supply so closely, why do an estimated that 600 million – almost 1 in 10 people in the world — fall ill after eating contaminated food? And 420,000 die every year, with children under the age of 5 years at exceptionally high risk. The African and South-East Asia Regions have the highest burden of foodborne diseases.^[4]

Before reading further, watch the short FAO video that describes how food safety is a shared responsibility.

Although some foods become contaminated during food processing, most foodborne illnesses originate from improper handling at home. Foods can be contaminated with disease-causing microbes, or pathogens, leading to nausea, vomiting, stomach cramps, and diarrhea. Symptoms range from mild discomfort to severe illness and, in rare cases, can be fatal.

What Are the Types of Foodborne Diseases?

According to the CDC, food scientists have identified more than 250 different foodborne diseases. They may be either infectious or toxic in nature. Most are foodborne infections caused by eating contaminated food containing live microorganisms, such as bacteria, parasites, or viruses. The infection then grows inside your body, making you sick. Foodborne infections can be sporadic, and most of us do not report them to health professionals. However, occasional outbreaks occur that put communities, regions, or even entire nations at risk.

In 1988, consumption of contaminated clams led to a large hepatitis A outbreak in Shanghai, China, affecting nearly 300,000 people. ^[5]  In 1994, a nationwide outbreak of salmonellosis linked to contaminated ice cream in the United States caused an estimated 224,000 illnesses. ^[6]

Live microorganisms are not the only culprits in food poisoning. These microbes can produce toxins that cause foodborne illnesses just like live bacteria, viruses, and molds do. Cooking does not destroy the toxins.

One of the biggest misconceptions about foodborne illness is that the last meal you ate triggers the disease. However, it may take several days for symptoms to appear. If you develop a foodborne illness, you should rest and drink plenty of fluids. Avoid antidiarrheal medications because they could slow your body’s ability to eliminate the contaminant.

How Do Microorganisms Reproduce?

Bacteria, one of the most common causes of foodborne infections and toxin production, are single-celled microbes too small to be seen with the human eye. They reproduce by one bacterium dividing into two, a process known as binary fission.  Like all living things, bacteria depend on certain conditions to survive and thrive. For them to reproduce at a level that will cause illness, these six conditions are involved: 1) food, 2) acid, 3) temperature, 4) time, 5) oxygen, and 6) moisture, or “FAT TOM” for short.

Each of these six factors contributes to bacterial growth in the following ways:

• Food: Bacteria require food to survive. For this reason, moist, protein-rich foods are good potential sources of bacterial growth.
• Acid: Bacteria do not grow in acidic environments. Therefore, lemon juice and vinegar serve as preservatives.
• Temperature: Most bacteria will proliferate between 40°F and 140°F (4°C and 60°C). USDA considers this to be the danger zone for microbial growth. (ServSafe® uses 41°F to 135°F as the danger zone for commercial foodservice.)  Cold temperatures do not kill the bacteria; they only prevent their reproduction. The optimal temperature required to destroy different types of bacteria varies, but temperatures above 165°F are effective against most. Therefore, you should use a thermometer to check the internal temperature of foods.
• Time: Bacteria require time to multiply. When small numbers of bacteria are present, the risk is usually low. Still, prolonged exposure under the right conditions can allow bacteria to multiply, increasing the risk of illness.  
• Oxygen: Most bacteria are aerobic and require oxygen to grow. They will not multiply in an oxygen-free environment, such as a vacuum-packaged container. A few bacteria are anaerobic and will only grow in oxygen-free environments.  Clostridium botulinum is anaerobic and causes the deadly botulism.
• Moisture: Bacteria need water to survive and proliferate in moist foods. Dry and salted foods have a lower risk of being a safety hazard. High levels of sugar also reduce the available moisture for bacteria.

What Foods are Potentially Hazardous?

Foods that have one or more of the “FAT TOM” conditions described above are considered potentially hazardous foods (PHFs). These foods are perishable and will spoil—or “go bad”—if left at room temperature for too long.

In general, a food is classified as a PHF if it falls into one of the following categories:

• Of animal origin, such as meat, milk, eggs, fish, shellfish, or poultry (including foods that contain any of these ingredients)

• Of plant origin that has been cooked, such as vegetables, beans, or fruits

• Raw sprouts, including bean, alfalfa, and radish sprouts

• Cooked starches, such as rice or pasta

• Soy-based foods, including soy milk or tofu

The table below compares those that fit into the PHF category with similar ones considered non-PHF.

One of the most important factors in handling food properly is temperature. Table 1.3B lists important temperatures to remember for foods.   One key tip is to “keep hot foods hot and cold foods cold,” as microbes do not reproduce in either.

attributions

This chapter is an adaptation of “Chapter 17. Food Safety” in Human Nutrition:2020 Edition by University of Hawai‘i at Mānoa Food Science and Human Nutrition Program licensed under a Creative Commons Attribution 4.0 International License.