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 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).
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?
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., Minarovi?ová, 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