The unseen protectors; spices!

I live in a society where eating in fast food restaurants is considered a sign of economic buoyancy. Little wonder that a lot of people consider me broke and local whenever I tell them I do not eat in fast food restaurants. However, my habit is not without reasons; I almost lost my dear life to food poisoning resulting from ingesting one of those fast processed foods. Once beaten, twice shy.

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Food-borne infections vs food poisonings

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Food-borne infections simply refer to infections that are acquired through consumption of foods. According to World Health Organization, food-borne infections are of infectious or toxic nature caused by, or thought to be caused by the consumption of food or water. This term is not to be confused with food poisoning, as a lot of people do. While food-borne infections cover the varieties of ill-health related reactions resulting from ingestion of foods containing live microorganisms or their toxins, food poisoning is a subset of food-borne diseases that is usually formed direct ingestion of preformed toxins of the microorganisms.

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Microorganisms responsible for causing food-related infections are often referred to as food pathogens. Even though pathogens range from virus, fungi, bacteria and protozoans; majority of the most common food-related infections are caused by bacteria. Bacterial food-borne pathogens have had a tremendous impact on public opinion as the most critical food-related risk factor affecting consumers. Since the early 1980s, numerous outbreaks involving foodborne pathogens; Salmonella spp., Listeria spp. and Escherichia coli (E. coli) have demonstrated the importance of food safety, including, proper food handling and cooking procedures at home, food service establishments and commercially available products.

Some of the food spoilage and foodborne pathogens are often found in the food processing environments, especially when dealing with raw animal products. They cause all sorts of problems that have defied all solutions despite the wide range of strong preservation techniques available in form of freezing, sterilizing, drying, adding preservatives among others. In fact, food manufacturers are increasingly relying on milder preservation techniques to comply with the consumers’ demand for foods with a more natural appearance and nutritious quality than those achieved by the robust techniques. In addition, consumers are increasingly refusing foods prepared with preservatives of chemical origin to achieve sufficiently long shelf life and a high degree of safety with respect to foodborne pathogenic microorganisms.

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Spices: adding flavours and fighting germs

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Many researchers are actively seeking for new natural preservatives that can sufficiently assure the safety of the food products. And this exactly is where spices come in. Spices are one of the natural preservatives under consideration because they contain compounds particularly the essential oils that have some antimicrobial activity to inhibit bacteria, yeasts, and molds. They have traditionally been found to be useful for food preservation as well as for medicinal purposes.

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Many of the commonly consumed spices in the world such as ginger, cinnamon, clove, garlic, etc. originated from Asia. They are not only used for food flavoring but also to help maintain health and promote wellness. A lot of researches have been done on the antimicrobial activities of commonly used spices, especially those popular in the tropical region where they freely grow in the wild or domesticated for their uses.

Spices generally possess a number of antimicrobial activities. They have been used as protection against the growth of pathogens, particularly bacteria and molds, which produce bacterial toxins and mycotoxins causing food poisoning and spoilage. Their constituent compounds have different modes of action on microbial cells. They could disrupt the cell membrane by increasing permeability and changing the bacterial metabolism, causing the above mentioned organisms to become susceptible to the antimicrobial effect of spices.

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Essential oils in spices

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The antimicrobial activities of extracts obtained from spice, herbs and other aromatic plants or parts thereof using organic solvent or steam distillation have been recognized for many years. Plants and plant extracts have been used since antiquity in folk medicine and food preservation, providing a range of compounds possessing pharmacological activities. Most commonly, the active antimicrobial compounds; often called phytochemicals are found in the essential oil fraction of the extracts. By definition, essential oils (also called volatile or ethereal oils) are aromatic oily liquids obtained from plant material. The oils can be obtained from the plant-based spice by fermentation, effleurage or different methods of extraction but the method of steam distillation is most commonly used for their commercial production.

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Naturally, essential oils are largely soluble in alcohol and to a limited extent; in water. They consist of mixtures of functional groups such as esters, aldehydes, ketones and terpenes. It has long been recognized that some essential oils and components have a wide spectrum of antimicrobial effects and these have been reviewed, as have the antimicrobial properties of spices. In addition to these antibacterial properties, essential oils and their components functional groups have been shown to exhibit several other properties such as antitoxigenic, antiparasitic, antiviral, antimycotic, and insecticidal properties.

The impact of essential oils on bacteria, especially on pathogens, has been extensively studied in the laboratory. E. coli was found to be more vulnerable to the essential oils of sage, rosemary, cumin, caraway, clove and thyme than P. fluorescens or Serratia marcescens. S. typhimurium was also more sensitive to oregano and thyme oils than P. aeruginosa. Findings have also found that essential oil compounds from many different plant sources inhibit many foodborne pathogens. S. aureus, L.monocytogenes, A. hydrophila, S. Typhimurium and C. botulinum were to some degree sensitive to extracts from linden flower, orange, lemon, grapefruit, mandarin, sage,rosemary, oregano, thyme, cinnamon, cumin, caraway, clove, thyme, allspice, mastic gum and onion.

Independent studies have shown that the essential oils in spices such as zingiberene and gingerol in ginger, methyl-cinnamate and eugenol in galangal and turmeronein in turmeric all possess inhibitory effects on the growth of some bacteria. In addition to antimicrobial activities, compounds like flavonoids found in some spices have antioxidant properties; that is, they are capable of protection against free radicals. The essential oils extracted from fresh and dried rhizomes of galangal have been demonstrated to have antimicrobial activities against a wide range of pathogens; including bacteria, fungi, yeast and parasite. Several researchers have reported terpen-4-ol, one of the monoterpenes in the essential oil from fresh galangal rhizomes, as possessing antifungal activity against Trichophyton mentagrophytes.

In addition to terpen-4-ol, a compound isolated from an n-pentane/ diethyl ether-soluble extract of dried galangal rhizomes, known as Acetoxychavicol acetate (ACA) was found to be active against some bacteria and many dermatophyte species. In addition, the ability of ACA to act as an anti-ulcer and anti-tumor agents as well as an inhibitor of chemically induced carcinogenesis has been well documented.

However, most researchers inevitably came to conclude that the effectiveness of essential oils decreases when experiments were conducted in vivo. This could well be due to specific components of the food matrix, such as proteins and fats, which immobilize and inactivate the essential oil components.

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Summary

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Spices are natural, mostly plant-related substances that are used as food additives for their flavour as well as preservative attributes. The presence of these substances in foods reduces the higher chance of food spoilage in a short term as well as food poisoning due to food pathogens. These spices have been demonstrated to have antimicrobial activities, hence their ability to guard against short term food spoilage. Their ability to guard against food pathogens is due to the presence of essential oils which have been extracted and tested for varying degrees of activities in several independent researches.

Thank you all for reading.

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References

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health line

wikipedia

food authority

springer link

national library of medicince