Microbial Contamination of Food Products: Types, Mechanisms, and Prevention

This article from Desklib provides an in-depth look at microbial contamination of food products, including the types of contamination and the mechanisms by which pathogens can enter food. Learn about the significance of this topic for food security and human health, and discover ways to prevent contamination and reduce the risk of food poisoning.

MICROBIAL CONTAMINATION OF FOOD PRODUCTS
By Name
Course
Instructor
Institution
Location
Date

Food contamination defines the presence of dangerous chemicals as well as microorganisms in
food which would result in illness upon consumption. Food contamination tales place when a
substance gets into contact with food that should not be in the food. In as much as there are
numerous scenarios that may lead to food contamination, most of such scenarios can be
classified under four main categories: biological, physical, cross-contamination and chemical
contamination (Allard et al., 2016).
Biological contamination occurs when toxins or bacteria come into contact with food and tends
to be one of the common causes of food spoilage as well a food poisoning. Biological food
poisoning may take place when dangerous bacteria, also known as pathogens find their way into
the food and are then consumed by human (Bhunia 2018). Bacteria are defined as small
microorganisms that have the ability to split and multiply at a very high rate. Under conditions
that are ideal for the growth of bacteria, a single cell bacteria is able to split numerous times to
the extent that is just seven hours, it would have multiplied to more than two million bacteria.
Some of the bacteria including salmonella, listeria and staphylococcus are very toxic by
themselves and at other times it is not the bacteria that tends to be harmful to humans but instead
the process by which the bacteria undergoes multiplication and production of waste. Important to
note is that not all the bacteria are harmful to th human body with some of them being quite of
benefit for example those that are found in yoghurt (Doe 2017).
Mechanisms of microbial contamination of food
Numerous steps are involved in taking food from the farm to the dining take, a process called the
food production chain. Microorganisms inclusive of the pathogens may find their way into the
food at the primary production stage, harvesting and slaughter and during post-harvest or post

slaughter (Gil et al., 2015). Microorganisms that are pathogenic in nature may be found
everywhere more or less from which they are directly or indirectly getting introduced into the
food. The various mechanisms or passages via which pathogenic microorganisms find their way
into food include pre-harvest contamination, pre-slaughter and post-harvest contamination.
Pre-harvest contamination
Pre-harvest factors: Plant foods can be subjected to contamination by pathogenic microorganism
while being grown in the fields through applied manure as fertilizer, water used for the purposes
of irrigation, practices of the workers as well as the migratory or the feral animals.
Water used for irrigation: The contamination of outbreaks of E. coli infection as well as mangoes
and tomatoes with salmonella has been suspected on contaminated water that has been used for
the purposes of irrigation (He & Sun 2015). A study that was carried out in crops established
positive results for salmonella, E. coli and Vibrio spp following an irrigation exercise that was
conducted using water which tested positive for the very pathogens. Studies and research have
established that the strategy used in the application of irrigation water has a direct influence on
whether the organism may be found to be linked with the edible part of the plant during harvest.
Manure used as a fertilizer: studies have established that some pathogens for example E. coli
have the ability to develop a resistance to acid and survive under extremely low pH
environments for example the human stomach acid (Hudson 2015). These pathogens have been
found to exhibit a long time of survival where E. coli can survive for about 21 months inside
manure that was gathered from sheep that was experimentally inoculated and held outside under
changing environmental conditions. Manures from such animals or even from untreated waste
may be composed of these pathogens that are resistant to pathogens and should they be used in

the fertilization of the plant crops especially with inappropriate application time prior to the
harvest, the raw plant food risk contamination (Lung et al., 2015).
Feral or Migratory animals: There are chances of pre-harvest contamination through feral or
migratory animals. Studies have established a strong correlation between animal reservoirs and
produce where most of the current out breaks associated with produce have tended toward
intrusion by wild animals into the planting and growing fields or through faecal contamination
from the neighbouring animal production facilities that likely resulted in the production of
contamination (Malhotra, Keshwani & Kharkwal 2015). Still, intrusion by animals has as well
been established as the most probable cause of contamination of the apples as is the case in cedar
orchards by deer or cattle.
Pre-Slaughter and Slaughter Contamination: The events that take place in the farms in which
animal foods are raised, in the feeding lots, during the process of transportation as well as large
before slaughter alongside during slaughter and the proceeding processing have a significant
impact on the microorganisms which are responsible for the contamination of food as well as on
the human health (Marriott, Schilling & Gravani 2018). By feeding poultry using infected
foodstuffs may lead to a great number of the chickens as well as their eggs being infected by
bacteria which poison food.
Other mechanisms through which flocks of poultry may get infected including drinking water,
dogs, cats, footwear, insects and human stool. Bacteria alongside other microbial pathogens
found in animals or those that can be found in farm or human equipment have the potential to
contaminate the surrounding which the animals are being brought up, where they roam or even
their points of being kept as they await bring slaughtered (Mizan et al., 2018).

Poultry farms that have large bird populations form a setting of quick spread of the pathogenic
contaminants resulting in the animals carrying the bacteria in their skins or hides or even in their
intestines. From the hides and the animal skins and the surrounding more specifically in cases
where care is not taken during the removal of the hide, such microbial pathogens are able to
easily find their way into poultry or meat during slaughter and thus may lead to cross-
contamination of other foods which may come into contact with the raw meat or poultry that is
contaminated (Muhterem-Uyar et al., 2015).
Post-Harvest/Slaughter Contamination
Food preparation/ food processing factors: Food preparation and processing define those factors
that are used in making changes in the food in such a way that alters the shelf life or the eating
quality. An example in this case may be the milling of wheat or fermentation of the flour. Food
processing tends to be a larger and broader term that goes beyond the preparation and cooking of
foods. It defines the application of technological and scientific principles in the preservation of
food by enabling deviations to the quality of eating of the foods (Nerín, Aznar & Carrizo 2016).
Current gaps: Despite the existence of lots if information on food poisoning and more
specifically microbial food poisoning, not so much studies have been conducted with the aim of
understanding the various mechanisms or ways of reducing or otherwise completely eliminating
these pathogenic microorganisms (Prakash et al., 2015). This has seen the pathogenic
microorganisms continually thrive and cause more and more harm to human health. This study
thus aims at addressing this concern by establishing numerous ways through which the
pathogenic microorganisms can be controlled in such a way that they have minimal impact on
human health if any.

Significance of the topic: Microbial contamination of food products provides the basis of
understanding food contamination, the various types of contamination as well as the different
mechanisms through which microbial pathogens get into food (Prakash et al., 2015). Such
information aids in the enlightenment of people who handle food products by providing them
with the information they may need in handling such foods in such a way that contamination is
reduced.
A sufficient supply of safe wholesome as well as healthy food is very important to the wellbeing
and the health of humans especially in keeping with the phenomenon of foo security as defined
by the Food and Agricultural Organization. It is for this reason that other than ensuring that
every person has access to adequate food, another challenge for food security is sneering that
such food such food is as safe as possible for biological, chemical and physical aspect of
contamination (Prakash et al., 2015).
Novel: A new research that may be carried out in this topic may be on the extent of
contamination of food and food products through microbial pathogens. This would include a
study into the prevalence of the mechanism as well as the most likely facilitating factors.
This study can thus be refined into a research question that the study would seek to address and
fully answer by the end of the research. The research question would be:
Which are the ways or mechanisms that can be used in the reduction or complete elimination of
the microbial contamination of food products?

References
Allard, M.W., Strain, E., Melka, D., Bunning, K., Musser, S.M., Brown, E.W. and Timme, R.,
2016. Practical value of food pathogen traceability through building a whole-genome sequencing
network and database. Journal of clinical microbiology, 54(8), pp.1975-1983:
jcm.asm.org/content/54/8/1975.full
Bhunia, A.K., 2018. Foodborne microbial pathogens: mechanisms and pathogenesis. Springer
Dasgupta, N., Ranjan, S., Mundekkad, D., Ramalingam, C., Shanker, R. and Kumar, A., 2015.
Nanotechnology in agro-food: from field to plate. Food Research International, 69, pp.381-400
Doe, P., 2017. QUALITY. In Fish Drying and Smoking (pp. 107-134). Routledge
Gil, M.I., Selma, M.V., Suslow, T., Jacxsens, L., Uyttendaele, M. and Allende, A., 2015. Pre-and
postharvest preventive measures and intervention strategies to control microbial food safety
hazards of fresh leafy vegetables. Critical reviews in food science and nutrition, 55(4), pp.453-
468 Bansal, V. and Kim, K.H., 2015. Review of PAH contamination in food products and their
health hazards. Environment international, 84, pp.26-38:
https://www.ncbi.nlm.nih.gov/pubmed/24915374
He, H.J. and Sun, D.W., 2015. Microbial evaluation of raw and processed food products by
Visible/Infrared, Raman and Fluorescence spectroscopy. Trends in Food Science &
Technology, 46(2), pp.199-210:
https://www.tandfonline.com/doi/full/10.1080/10942912.2017.1338729
Hudson, N., 2015. Soil conservation: fully revised and updated(No. Ed. 3). New India Publishing
Agency

Lung, H.M., Cheng, Y.C., Chang, Y.H., Huang, H.W., Yang, B.B. and Wang, C.Y., 2015.
Microbial decontamination of food by electron beam irradiation. Trends in Food Science &
Technology, 44(1), pp.66-78: scholar.google.com/citations?user=e0nRjekAAAAJ&hl=en
Malhotra, B., Keshwani, A. and Kharkwal, H., 2015. Antimicrobial food packaging: Potential
and pitfalls. Frontiers in microbiology, 6, p.611
Marriott, N.G., Schilling, M.W. and Gravani, R.B., 2018. Principles of food sanitation. Springer
Mizan, M.F.R., Jahid, I.K. and Ha, S.D., 2015. Microbial biofilms in seafood: a food-hygiene
challenge. Food microbiology, 49, pp.41-55
Muhterem-Uyar, M., Dalmasso, M., Bolocan, A.S., Hernandez, M., Kapetanakou, A.E., Kuchta,
T., Manios, S.G., Melero, B., Minarovičová, J., Nicolau, A.I. and Rovira, J., 2015.
Environmental sampling for Listeria monocytogenes control in food processing facilities reveals
three contamination scenarios. Food Control, 51, pp.94-107
Nerín, C., Aznar, M. and Carrizo, D., 2016. Food contamination during food process. Trends in
Food Science & Technology, 48, pp.63-68
Prakash, B., Kedia, A., Mishra, P.K. and Dubey, N.K., 2015. Plant essential oils as food
preservatives to control moulds, mycotoxin contamination and oxidative deterioration of agri-
food commodities–Potentials and challenges. Food Control, 47, pp.381-391