Antimicrobial Activities of Essential Oils, Plant Extracts and their Applications in Foods- A Review (2025)

Essential Oils as Antimicrobials

Madridge Journal of Food Technology, 2019

This paper is a review of essential oils and their use in foods, packaging materials and farm animals. Essential oils are aromatic oil liquids obtained from plant materials. They serve crucial roles as antioxidants, pathogen inhibitors and flavoring agents. Because of label appearance concerns, essential oils are increasingly used as food preservatives. Essential oils have a complex composition and properties that vary based on differences in field growth, postharvest and processing conditions. Chemical and physical properties of essential oils affect their ability to act as antimicrobials. The food matrix has a significant impact on the antibacterial properties of essential oils, based on factors like pH, fat and moisture content. Meat products have experienced broad application of essential oils as preservatives, while fish and seafood have seen limited use. Essential oils have been used to clean and preserve vegetables, rice and fruits. Food coatings and packaging materials have been treated with essential oils to enhance food preservation properties. Many factors influence the activity of essential oils in foods including synergism (vacuum packaging, pH, water activity, other preservatives and sodium chloride), antagonism (composition of food and sodium chloride) and additive effects. Many essential oils are regarded as safe, but under certain conditions, they may cause dermatitis and cytotoxicity. Challenges to the expanding use of essential oils as antimicrobials in the food industry include organoleptics, uniformity of composition, and emerging resistance of microbes.

Essential oils: their antibacterial properties and potential applications in foods—a review

International Journal of Food Microbiology, 2004

In vitro studies have demonstrated antibacterial activity of essential oils (EOs) against Listeria monocytogenes, Salmonella typhimurium, Escherichia coli O157:H7, Shigella dysenteria, Bacillus cereus and Staphylococcus aureus at levels between 0.2 and 10 Al ml À 1 . Gram-negative organisms are slightly less susceptible than gram-positive bacteria. A number of EO components has been identified as effective antibacterials, e.g. carvacrol, thymol, eugenol, perillaldehyde, cinnamaldehyde and cinnamic acid, having minimum inhibitory concentrations (MICs) of 0.05 -5 Al ml À 1 in vitro. A higher concentration is needed to achieve the same effect in foods. Studies with fresh meat, meat products, fish, milk, dairy products, vegetables, fruit and cooked rice have shown that the concentration needed to achieve a significant antibacterial effect is around 0.5 -20 Al g À 1 in foods and about 0.1 -10 Al ml À 1 in solutions for washing fruit and vegetables. EOs comprise a large number of components and it is likely that their mode of action involves several targets in the bacterial cell. The hydrophobicity of EOs enables them to partition in the lipids of the cell membrane and mitochondria, rendering them permeable and leading to leakage of cell contents. Physical conditions that improve the action of EOs are low pH, low temperature and low oxygen levels. Synergism has been observed between carvacrol and its precursor p-cymene and between cinnamaldehyde and eugenol. Synergy between EO components and mild preservation methods has also been observed. Some EO components are legally registered flavourings in the EU and the USA. Undesirable organoleptic effects can be limited by careful selection of EOs according to the type of food. D

Preliminary studies on the antimicrobial activity of essential oils against food borne bacteria and toxigenic fungi

2011

The aim of this research was to evaluate the in vitro antimicrobial activity of seven essential oils against four different bacterial and five fungal strains that are involved in food poisoning and/or food decay: Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enteritidis, Fusarium graminearum, Fusarium culmorum, Aspergillus flavus, Aspergillus oryzae and Aspergillus brasiliensis, using two methods: agar disc diffusion method and disc volatilization method. The majority of the selected essential oils presented inhibitory activity against all the microorganisms tested but essential oils of oregano, thyme and clove proved to develop the best antibacterial and antifungal activity both in direct contact and volatilization method and could be used for further investigation in active packaging of food.

Functional Role of Essential Oils as Antimicrobial and Antioxidat Agents in Food Industry: A Review

Essential oils (EOs) possess both antimicrobial and antioxidant activities in food systems. Variations in EOs effectiveness were dictated by their components, effective concentrations, intrinsic factors of food composition as well as extrinsic factors such as storage temperature. The antimicrobial and antioxidant activities of EOs are a result of the presence of phenolic components at high concentrations. EOs could have better effectiveness than single component because these constitutes could act additively or even synergistically in EOs. EOs have antimicrobial activity against wide range of microorganisms and their mode of action is related to disintegration of cellular membrane integrity followed by inactivation of other microbial cells components. The antioxidant mode of action for EOs is related to neutralization free radicals and peroxide decomposition in particularly when tested in meat, dairy, fruits and vegetables. The high effectiveness of EOs indicates that they could replace the synthetic food additives. This scientific review summarizes the most recent studies about effectiveness of EOs as antimicrobial and antioxidant agents to be used in food industry.

Antibacterial potential of essential oils from medicinal plants for food preservation: a review

Medicinal Plant Communications, 2021

Essential oils, also called volatile or ethereal oils, are compounds naturally present in plants. Several medicinal plants are sources of these essential oils extraction, besides different secondary metabolites that are produced, such as terpenoids, alcoholic compounds, aldehydes, ketone bodies and phenols. The essential oils usage as substitutes for synthetic preservatives in food has been gaining space in research due to the interest of the populationin consuming healthier products. Moreover, the industry seeks to attend the necessities of the consumers to produce foods with less synthetic additives, but ensuring the preservation of organoleptic characteristics and shelf life. This review aims to present the antibacterial activity of essential oils from medicinal plants and its use as a food preservative.

Title : “ Antimicrobial activity of plant essential oils using food model 1 media : efficacy , synergistic potential and interactions with food 2 components ” 3 4

2017

The aim of this study was to optimize the antimicrobial efficacy of plant essential oils (EO's) for control of Listeria spp. and spoilage bacteria using food model media based on lettuce, meat and milk. The EO's evaluated were lemon balm, marjoram, oregano and thyme and their minimum inhibitory concentrations (MIC) were determined against Enterobacter spp., Listeria spp., Lactobacillus spp., and Pseudomonas spp. using the agar dilution method and/or the absorbance based microplate assay. MICs were significantly lower in lettuce and beef media than in TSB. Listeria strains were more sensitive than spoilage bacteria, and oregano and thyme were the most active EO's. EO combinations were investigated using the checkerboard method and Oregano combined with thyme had additive effects against spoilage organisms. Combining lemon balm with thyme yielded additive activity against Listeria strains. The effect of simple sugars and pH on antimicrobial efficacy of oregano and thyme was assessed in a beef extract and tomato serum model media. EO's retained greater efficacy at pH5 and 2.32% sugar, but sugar concentrations above 5% did not negatively impact EO efficacy. In addition to proven antimicrobial efficacy, careful selection and investigation of EO's appropriate to the sensory profile of foods and composition of the food system is required. This work shows that EO's might be more effective against food-borne pathogens and spoilage bacteria when applied to foods containing a high protein level at acidic pH, as well as moderate levels of simple sugars.

Essential Oils and Their Application in Food Safety

Frontiers in Sustainable Food Systems, 2021

Food industries are facing a great challenge due to contamination of food products with different microbes such as bacteria, fungi, viruses, parasites, etc. These microbes deteriorate food items by producing different toxins during pre- and postharvest processing. Mycotoxins are one of the most potent and well-studied toxic food contaminants of fungal origin, causing a severe health hazard to humans. The application of synthetic chemicals as food preservatives poses a real scourge in the present scenario due to their bio-incompatibility, non-biodegradability, and environmental non-sustainability. Therefore, plant-based antimicrobials, including essential oils, have developed cumulative interest as a potential alternative to synthetic preservatives because of their ecofriendly nature and generally recognized as safe status. However, the practical utilization of essential oils as an efficient antimicrobial in the food industry is challenging due to their volatile nature, less solubili...

Antimicrobial activity of essential oils

Journal of Essential Oil Research, 2014

Of late, there is a rapidly growing demand of environmental friendly, safe preservatives for food preservation because some of the traditional food preservation techniques have undesirable effects on the quality of food products and the artificial preservatives are increasingly being banned. This has necessitated the need to exploit the natural biological substances from plants which are safe and are capable of preserving the food products. Antimicrobial is a chemical compound present in or added to food, food packaging, food contact surfaces or food processing environments that inhibits the growth of or inactivate pathogenic or spoilage causing microorganisms. Many plants contain compounds that have some antimicrobial activity, collectively referred to as "green chemicals". Volatile oils of many plants are known to have antimicrobial activity, which could probably act as chemical defense against plant pathogen. Among the essential oil components, the volatiles monoterpenes and aldehydes have attracted the recent interest of researchers and food industries for their use as food preservatives. Various herbs and spices have been found to have broad spectrum activity against a number of bacteria and fungi, hence showing their potential for their use in foods as antimicrobial additives. In this article, efforts have been made to present the information pertaining to various plant species especially essential oils having some antimicrobial compound, their antimicrobial activity, mode of action, application in food preservation and other related aspects.

Exploring the Antibacterial Potential of Essential Oils Extracted from Three Medicinal Plants Against Some Foodborne Bacteria

Catrina Journal, 2023

This study aims to evaluate the antibacterial activity of essential oils extracted from the green leaves of three medicinal plants, namely Cupressus macrocarpa, Schinus terebinthifolius, and Eucalyptus citriodora, against selected foodborne bacteria. Gas chromatography/mass spectrometry (GC/MS) analysis was employed to identify the chemical composition of the extracted essential oils. The two main chemical components of C. macrocarpa essential oils (EO) were terpinene-4-ol (32.37%) and citronellol (29.29%). The primary components of S. terebinthifolius EO were α-phellandrene (44.35%) and o-cymene (10.42%). Meanwhile, αphellandrene (13.5%) and sabinene (24.24%) constitute the majority of E. citriodora EO. The antibacterial activity of the essential oils was assessed against Gram-positive bacteria including Bacillus cereus, Staphylococcus saprophyticus, Lysinibacillus fusiformis, and Kocuria rhizophila, as well as the Gram-negative bacterium Serratia liquefaciens. Standard antibiotics like Penicillin, Amoxicillin, and Ampicillin were used for comparison. The results revealed varying degrees of antibacterial activity against each pathogenic isolate used. C. macrocarpa essential oil exhibited the strongest antibacterial action, with a 55.7 mm inhibition zone diameter against Bacillus cereus, which displayed resistance to the tested standard antibiotics. Meanwhile, essential oils of the choosed plants also inhibited the growth of S. liquefaciens despite its tolerance to the tested antibiotics. The minimum inhibitory concentrations (MIC) of C. macrocarpa, S. terebinthifolius, and E. citriodora essential oils ranged from 0.06 to 1.5 mg/ml, 0.68 to 2.0 mg/ml, and 0.2 to 1.77 mg/ml, respectively. These findings highlight the potential of the tested essential oils as antibacterial agents for preserving food materials in a safe, sustainable, cost-effective, and ecofriendly manner.

Essential Oils: Sources of Antimicrobials and Food Preservatives

Frontiers in Microbiology, 2017

Aromatic and medicinal plants produce essential oils in the form of secondary metabolites. These essential oils can be used in diverse applications in food, perfume, and cosmetic industries. The use of essential oils as antimicrobials and food preservative agents is of concern because of several reported side effects of synthetic oils. Essential oils have the potential to be used as a food preservative for cereals, grains, pulses, fruits, and vegetables. In this review, we briefly describe the results in relevant literature and summarize the uses of essential oils with special emphasis on their antibacterial, bactericidal, antifungal, fungicidal, and food preservative properties. Essential oils have pronounced antimicrobial and food preservative properties because they consist of a variety of active constituents (e.g., terpenes, terpenoids, carotenoids, coumarins, curcumins) that have great significance in the food industry. Thus, the various properties of essential oils offer the possibility of using natural, safe, eco-friendly, cost-effective, renewable, and easily biodegradable antimicrobials for food commodity preservation in the near future.