Home

Microbiology is the study of organisms. These organisms consist of bacteria, fungi, viruses, parasites, etc. There are many sources of microorganisms in our foods, such as resulting from packaging, from coming into contact with surfaces, animals, and insects, as well as the food handlers themselves. It is impossible to look at a food product and be able to tell whether or not microorganisms have contaminated that food product. Microbes do not change anything about the food visually, or sensory wise. A foodborne outbreak is referred to as whenever two or more people undergo the same illness after consuming the same food product. About half of the outbreaks have an unknown food source. There are a multitude of costs associated with foodborne outbreaks. For example, there are personal costs, such as medical costs and cost of lost productivity. There are also industry costs, such as recalls and lost businesses. It is estimated that 6.5-35 billion dollars are lost annually in the United States due to food borne illnesses. There are two types of foodborne illnesses, infection and intoxication. Infection is when a consumer eats a particular type of food and the bacteria in that food multiplies in the intestinal tract of the consumer, which leads to illness. Intoxication is when a consumer eats a particular food that has already been infected with growing bacterial colonies. Those bacteria reproducing in the food product release a toxin that ultimately causes illness in the consumer. Bacteria are tiny single celled organisms in which some are beneficial, but most are deleterious to our health. One of the most common foodborne outbreaks is due to the Salmonella bacterium. The symptoms of Salmonella are having nausea, vomiting, diarrhea, abdominal pain, and fever. One can become infected with Salmonella with consuming as little as 1 to 10 cells of Salmonella. Some food sources that may contain Salmonella are eggs, beef, almonds, sprouts, chicken, peanuts, etc.

Screen Shot 2014-03-16 at 7.36.34 PM

Another very common foodborne illness is a result of consuming Escherichia Coli. The symptoms of being infected with Escherichia Coli are having cramps, nausea, vomiting, bloody diarrhea, and sometimes kidney failure and dementia. It takes time to fully develop the disease, since the symptoms start quickly but they get slowly worse. Again as little as one to ten cells can cause an individual to be infected with this bacteria, therefore we have an extremely low tolerance to this microbe. Some sources of food that may contain E. Coli are drinking water, swimming water, apple cider, lettuce, spinach, and salami. E. Coli has moved into wild ruminants like deer and elk, hence no one knows how to get this disease out the food supply. In the past there have been outbreaks in Oregon after people have consumed undercooked hamburgers. E. Coli is a relatively rugged organism, so slightly acidic food that we think would not have a microbe living in it could in fact be infected with E. Coli.

Screen Shot 2014-03-16 at 7.36.27 PM

Some examples of E. Coli outbreaks are in 1982 Jack in the Box served under cooked hamburgers that contained E. Coli, as well as Odwalla had E. Coli in their unpasteurized juices. Therefore, Odwalla pasteurizes all of their juices and Jack in the Box cooks all of their burgers well done. Another very common foodborne illness is Listeria monocytogenes. This bacterium has symptoms consisting of infections, such as blood infections and nervous system infections. Most people that consume this bacterium do not become ill, but people with very poor immune systems can become infected by this microbe. People who have compromised immune systems are pregnant women, and elderly adults. There was previously an outbreak with this bacterium in 1981 in which people consumed infected cabbage. Some sources of this bacterium may result from soft cheese, chicken, pate, seafood, and hotdogs. This microbe is everywhere since it is a soil borne organism. All plants come into contact with soil so there is a high chance of all plants having Listeria. Almost everything comes into contact with soil, including water that percolates through soil. Hence, Listeria is wide spread in our food supply. Some ways that people may prevent themselves from catching a foodborne illness is by washing their fruits and vegetables well before they consume them, along with they should practice safe food handling by not cross contaminating their foods. An example of cross contamination would be using the same cutting board to cut cabbage after you have just used that cutting board to cut chicken. Therefore, one should wash their utensils and cutting boards before and after use. Also one should avoid fruits and vegetables that have been grown in fertilizer that contains fresh manure. People that are immunocompromised should avoid juices and milk that have not been pasteurized, as well as raw meat, seafood, and deli meats. People should also cook their foods at high temperatures so that they are certain that they have killed the deleterious bacteria that could have been present in their food product. Also, if one were to consume foods that have been irradiated, then they will not become ill, considering irradiated food products contain no pathogens.

One could also become ill due to a virus being present on a certain food product. Viruses can be beneficial, although the viruses found on foods are very deleterious to consumers. In general, food handlers are the source of viruses on food products. In some countries food handling is a profession, but in the United States if one simply graduates high school they can be a food handler. This may lead one to believe that the United States should require that our food handlers go to school more to learn more about proper food handling. If the United States were to require this extensive educational program for our food handlers, one may believe that the number of cases and outbreaks of people becoming infected from foodborne viruses would decrease dramatically. Viruses are not living but they are infectious agents that need to be in a living person or cell to be able to reproduce/divide. There are a multitude of viruses that can infect us, such as Hepatitis A. Hepatitis A has resulted from human fecal matter being in food in the past, such as in 1988 in China.

Parasites can also be found on our food products. Parasites are multi-celled organisms that need a host to live off from. A lot of the time they are found in water and raw food products. Parasites are very dangerous when they use humans as their host, because they steal vital nutrients from our bodies and use them for their own selfish needs.

Screen Shot 2014-03-16 at 7.36.19 PM

An example of a parasite would be Giardia. Giardia is the most common parasite infection people get from food products. This parasite was transferred as a result of fecal matter on one’s hands coming into contact with food. An example of foodborne intoxication is Bacillus cereus. This bacteria forms spores on food products and infects people that eat the food products that contain Bacillus cereus. The symptoms of being infected with this bacterium are having diarrhea and vomiting. The symptoms of being infected with bacillus cereus usually only last for about a day. Some food sources of this bacterium are foods that are not completely cooked, as well as foods that are found in soil, eggs, and dairy products. Molds can also contaminate our food products. Molds can grow on a wide range of food products, such as corn and bread. One can lower their risk of being infected by this bacterium by refrigerating their food products properly, as well as not leaving foods out for a long period of time, as well as practicing proper safe handling practices when preparing the food product. Overall, someone needs to figure out how to get rid of these bacteria from the food supply. One has to decide what is an acceptable risk to take in return for a nutrient dense food, since no one can obtain a perfect no risk food product. Therefore, everyone attempts to avoid these bacteria by taking certain precautions that are set out by scientists that have studied the transmission and intoxication of these bacteria in humans. In addition to eliminate microbes and microorganisms present on a food product one can always just cook their foods. For example, most milk is heat treated, and therefore undergoes pasteurization to kill all the microorganisms present in the milk. When heat is applied to a food product the biopolymers are irreversibly destroyed/denatured, and membranes rupture. Heat treatments need to be precisely completed, considering we need to apply enough heat to make sure we have killed all the organisms present on the food product, but not apply so much heat that that it makes the nutritional value of the food product decrease. There is a machine that completes this heat treatment precisely and perfectly, and it is called the heat exchanger. The heat exchanger quickly heats then cools foods, which eliminates the microorganisms but at the same time does not damage the nutritional value of the food product. The only problem is the heat exchanger can only work on homogenous fluids, and not all foods are homogenous fluids. In foods that are not homogenous fluids the heat transfer does not occur throughout the product evenly. Heat treatment is no the best way to kill the microorganisms on one’s nonhomogeneous food product. One could use a filtration process to filter out all microorganisms, since the filter used would have to be around 0.45 micrometers, which is small enough to capture the microorganisms present in the food. The only problem with this method of eliminating microbes from one’s food is that it can only be used for fluids that are homogenous in nature. Irradiation of food products is another good method by which microbes can be eliminated from food products. Food irradiation uses x-rays and gamma rays to ionize the DNA of the microorganisms present in the food, thereby killing them. The benefit of utilizing this process is that it can be used on all food products and result in elimination of microbes as well as preservation of the nutritional value of the food product.

There are three types of microorganisms that cause a food product to spoil and consist of: bacteria, yeasts, and molds. One can hinder the growth of these microorganisms by utilizing preservatives. Many different types of preservatives are approved by the FDA for usage in food products, such as sulfur dioxide and nitrites. These are chemical preservatives that are widely used in food products. Even some kinds of spices can be used to preserve foods by hindering microbial growth.

Screen Shot 2014-03-16 at 7.36.12 PM

Benzoic acid, sorbic acid, and propionic acid are the three best preservatives used in food products. Some processed foods utilized preservatives as well as many other techniques to preserve the food product. Some processed foods are salted and/or fermented to prolong their shelf life. Some products are even dried and spices are added to prolong the shelf life of the food even more. Researchers at Aarhus University have found many natural spices and fruits that can be used as preservatives, such as red currant, sage, cranberry, horseradish, ramson, savoury, sloe, and chokeberry (Nielsen). Salami and cheese are both examples of food products that utilize multiple preservation methods in processing.

Everyone has different levels of susceptibilities to becoming ill due to a foodborne illness. Infants and elderly individuals do not produce as much stomach acid so the bacteria in foods don’t get killed as much in comparison to someone in the prime of their lives. People’s susceptibility to becoming ill due to a foodborne illness depends on their genetics, age, and metabolic and immunological state. One’s susceptibility to obtaining food allergies depend on their genetic predisposition somewhat, since you need to have a genetic predisposition to be able to be allergic to a particular food. Under certain environmental conditions food allergies can come about if one is genetically predisposed to get it. The more someone is exposed to an allergen the more they can develop a tolerance to that allergen, therefore reducing their chance of becoming allergic to that specific allergen. Although, if someone is already allergic to a particular allergen and they keep getting exposed to that allergen, then that person becomes more and more allergic to that allergen. Therefore, some people without allergies can build up a tolerance to allergens but if someone is already allergic to an allergen they cannot become sensitized to that allergen. An example of how certain people are predisposed to being allergic to certain things involves the microbiota of infants. Infants get infections a lot, such as ear infections. When infants get infections their parents take them to the doctor, who prescribes antibiotics and baby aspirin for pain. These medicines change the infants’ gut microbiota, making them more susceptible to developing allergies to certain foods that are introduced at the point in time while they are on those medications. Hence, allergies can be brought on by a variety of different factors.

Since there are many factors involved in food safety, NASA went to the Pillsbury Company to develop a system for evaluating all possible hazards in foods, since getting a foodborne illness in space would be severely bad and cause many problems.  Therefore, they developed the HACCP (Hazard Analysis Critical Control Points). The HACCP evaluates the different steps of food processing and handling, and finds the points where there could be a safety hazard. The HACCP works to eliminate these safety hazards that are present in the food handling and producing business. The HACCP has become the standard of the food industry. The HACCP educates the public on the safe food handling practices through their website: www.foodsafety.gov. They have certain categories of the website directed towards the people at risk the most, which are the people who are immunocompromised due to them being elderly or pregnant. This category of their website aims to share with these people how they are at risk for getting a foodborne illness. They also have food education about viruses in food products. This is a very important concept since some pathogens and viruses can lead to cancer. Such as the Human Papilloma Virus, which is associated with a virus. There is thankfully now a cure for this cancer, and vaccines are being utilized all over the world. Even though the HACCP was made and they attempt to educate the public as good as they can, the public’s education is still lacking on the topic of foodborne illnesses.

Resources:

Nielsen, Mathias. “Herbs and Berries Can Preserve Meat.” Sciencenordic.com. Science Nordic, 7 Mar. 2012. Web. 16 Mar. 2014.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s