Essential oils: antimicrobial, antioxidant properties, and their applications in food preservation—a comprehensive review

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Fatty acid-modified chitosan and nanoencapsulation of essential oils: A snapshot of applications

Essential oils (EOs) are secondary metabolites synthesised by many aromatic plants, which have good antimicrobial and antioxidant activities making them popular functional agents for food preservation and packaging applications. In recent years, novel extraction techniques, such as super critical fluid extraction, pulsed electric field assisted extraction and ultrasound assisted extraction have been explored as alternatives to the conventional solvent‐based extraction methods. This review mainly discusses on recent progresses in sustainable extraction of essential oil (EO) from aromatic plants and food processing wastes and their functional properties, and applications in food preservation have also been summarised. Sustainable extraction techniques yield better‐quality EO due to low temperature and short time process compared to the conventional extraction. Despite efficacy of EOs as good active agents, their low water solubility, volatile nature, strong flavour, and susceptibility to food processing parameters are major challenges against their applications in food. These challenges can be mitigated by advanced techniques such as encapsulation and nanoemulsification of EO, which provide dual functions of enhanced applicability and improved functional properties. Incorporation of EO in the biopolymer‐based films and coatings can open avenues for sustainable food packaging and preservation.

Essential oils are complex mixture of compounds that formed by aromatic plants as secondary metabolites. Its inimitable composition plays as multicomponent systems in plant defense with antimicrobial and insecticidal properties. Except these, essential oils bear other key properties like antioxidant, insecticidal, antiphlogistic, spasmolytic, antiparasitic, and antiviral. Insect infestations and fungal infections are the chief cause of postharvest damage of fresh fruits, vegetables, and cereals throughout storage and transportation. The biodeterioration of harvested and stored products is also directly influenced by hot and humid climate. Utilization of essential oils can replace synthetic fungicides and insecticides in management of such issues. Currently, essential oils are utilized as preservatives in many food and flavor industry, perfumery, and pharmaceutical industries. This chapter aimed to provide the current scenario about the antifungal and insecticidal potential of essential oils and their constituents to identify research avenues that can facilitate its implementation as natural food preservatives in food commodities.

Despite advancements in food preservation ways, the nature of preservatives remains one of the real problems that must be taken into account for the preservation of consumer health. To cope with the problems of contamination and oxidation of foodstuffs, the chemistry development has favored the appearance and application of new chemical substances such as benzoates, sulphites, calcium chloride, acid citric etc. used as synthetic food preservatives. Subsequently, several of these synthetic preservatives have been banned in some countries because of their long-term adverse toxicological effects. The current trend of consumers seeking healthier diets is forcing them to use natural products with antimicrobial and antioxidant activities such as essential oils. These aromatic plant extracts, whose antioxidant power has been widely proven in the literature, also contain substances with very interesting biological activities, less polluting for the environment, with minor effects on the health of consumers. In this review, we have highlighted the antioxidant potential of essential oils for food quality improvement and preservation.

MALAGASY AROMATIC PLANTS: ESSENTIAL OILS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES

In recent years, plant essential oil (EO) is considered a potential food preservative because of its antibacterial and antioxidant properties. High safety and natural are the main advantages of its application. However, the direct use of EO has many limitations, such as low water solubility, high volatility, high sensitivity to the environment and strong odor. Therefore, encapsulating EOs to form a capsule-like substance is an effective way to protect the activity of EOs. Encapsulation could improve the stability of bioactive compounds, and endow EO with sustained-release characteristics which could extend the actuation duration. Except for playing an antibacterial role, the use of EOs as preservatives in food preservation also helps to protect or improve certain physicochemical properties of food to maintain the overall quality of food. This review classifies and summarizes the encapsulation methods, wall materials and effects of several EOs with strong antimicrobial activity, and clarifies the factors that affect the release of EOs from capsules. The application of EO capsules in food preservation and their various forms of preservation are also summarized to provide more references for future research.

Essential oils: A promising eco-friendly food preservative.

BackgroundPlant-based essential oils are complex natural products composed of volatile compounds with wide applications in food, cosmetics, and pharmaceuticals. Their bioactive properties, including antimicrobial, antioxidant, and anti-inflammatory effects, make them promising candidates for food flavoring, preservation, and therapeutic uses. Variations in chemical composition are influenced by geographical, climatic, and extraction factors, necessitating further investigation into their functional roles.ObjectiveThis review aims to explore the versatile applications of plant-based essential oils, emphasizing their use in food flavoring, culinary practices, and health benefits. The paper highlights their potential as natural preservatives, flavor enhancers, and bioactive agents, while also addressing challenges such as toxicity, allergenicity, and interactions with food components.MethodsA comprehensive literature review was conducted to analyze studies on the extraction methods, chemical compositions, and biological activities of essential oils. Data was gathered to evaluate their antimicrobial, antioxidant, and preservative properties, along with their impact on food quality and safety. ResultsEssential oils exhibit significant antimicrobial and antioxidant activities, enabling their use as natural preservatives in food systems, active packaging, and edible coatings. Their incorporation into products such as cheese, ice cream, and beverages has demonstrated enhanced sensory attributes and prolonged shelf life. Encapsulation techniques have shown promise in minimizing interactions with food matrices, ensuring stability, and preserving bioactivity. ConclusionsPlant-based essential oils represent versatile natural additives with functional and sensory benefits. Their antimicrobial, antioxidant, and flavor-enhancing properties support their use in food preservation and flavoring. Encapsulation techniques effectively address challenges related to solubility and stability, enhancing their practical applications. However, further research is needed to evaluate their interactions with food components, optimize dosages, and assess long-term safety. These insights highlight essential oils as valuable ingredients for natural, sustainable, and health-promoting food products.

Essential oils (EOs) are secondary metabolites produced by aromatic and medicinal plants. These oils have a wide range of applications in the culinary, perfume, antimicrobial and food industries. Because of several reported side effects of synthetic oils, the use of essential oils as antimicrobials and food preservatives is a source of concern. For cereals, grains, pulses, fruits, and vegetables, essential oils have the potential to be employed as a food preservative. When compared to synthetic compounds, EOs derived from safe natural sources and are effective for human health. This chapter will shed light on some medicinal plants that are rich in essential oils, as well as their antimicrobial properties. Because essential oils are rich in a number of active ingredients [e.g., terpenes, terpenoids, carotenoids, coumarins, curcumins] that are important in food industry, they have strong antimicrobial and food preservation. As a result of the diverse properties of essential oils, they can be used in a natural, safe, eco-friendly, cost-effective and renewable manner. Examples of some foodborne diseases will also be highlighted.

Perishable products such as fruits and vegetables account for the largest proportion of food loss due to their short shelf life, especially in the absence of proper storage facilities, which requires sustainable, universal and convenient preservation technology. The existing methods to prolong the shelf life of food mainly include adding preservatives, irradiation, cold storage, heat treatment and controlled atmosphere storage. But with disadvantages in irradiation, cold storage, heat treatment and controlled atmosphere storage, chemical synthetic preservatives are still the main means to control food corruption. As the food industry responds to the increasing consumer demand for green, safe and sustainable products, it is reformulating new products to replace chemical synthetic food additives. Essential Oils as Antimicrobial Agents in Food Preservation provides a comprehensive introduction to the antimicrobial activity of plant essential oils and their application strategies in food preservation. It is aimed at food microbiology experts, food preservation experts, food safety experts, food technicians and students. Features: Summarizes the application strategy and safety of essential oil in the field of food preservation Describes the synergistic antibacterial effect of essential oil and antimicrobial agents Explains the action mechanism of essential oil as antimicrobial agent against foodborne fungi, foodborne bacteria, viruses and insects Analyzes the antimicrobial activity of essential oil in gas phase The book discusses how as a natural antimicrobial and antioxidant, essential oil has great potential to be used in the food industry to combat the growth of foodborne pathogens and spoilage microorganisms. But because the essential oil itself has obvious smell and is sensitive to light and heat, it cannot be directly added to the food matrix and thus the application strategies presented in this book explain how to alleviate those issues.

Essential oils are aromatic and volatile liquids extracted from plants. The chemicals in essential oils are secondary metabolites, which play an important role in plant defense as they often possess antimicrobial properties. The interest in essential oils and their application in food preservation has been amplified in recent years by an increasingly negative consumer perception of synthetic preservatives. Furthermore, food-borne diseases are a growing public health problem worldwide, calling for more effective preservation strategies. The antibacterial properties of essential oils and their constituents have been documented extensively. Pioneering work has also elucidated the mode of action of a few essential oil constituents, but detailed knowledge about most of the compounds’ mode of action is still lacking. This knowledge is particularly important to predict their effect on different microorganisms, how they interact with food matrix components, and how they work in combination with other antimicrobial compounds. The main obstacle for using essential oil constituents as food preservatives is that they are most often not potent enough as single components, and they cause negative organoleptic effects when added in sufficient amounts to provide an antimicrobial effect. Exploiting synergies between several compounds has been suggested as a solution to this problem. However, little is known about which interactions lead to synergistic, additive, or antagonistic effects. Such knowledge could contribute to design of new and more potent antimicrobial blends, and to understand the interplay between the constituents of crude essential oils. The purpose of this review is to provide an overview of current knowledge about the antibacterial properties and antibacterial mode of action of essential oils and their constituents, and to identify research avenues that can facilitate implementation of essential oils as natural preservatives in foods.

Construction of bilayer emulsion gel with composite essential oils based on A-type gelatin and gum arabic: Potential application in food preservation.

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.

Essential oils (EOs) from various medicinal and aromatic plants are known for their diverse biological activities, including their antimicrobial effects. Citrus aurantium EO is traditionally used for therapeutic benefits due to its high content of bioactive compounds. Therefore, this study focuses on its potential use as a food preservative by investigating the combined antibacterial properties of EOs from leaves (EO1), flowers (EO2), and small branches (EO3) of Citrus aurantium against six bacterial strains by the agar disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The chemical compositions of the EOs were analysed by gas chromatography–mass spectrometry (GC-MS) and revealed the presence of numerous compounds responsible for their antimicrobial properties. The MIC values for the EOs were 3.12 mg/mL, 4.23 mg/mL, and 1.89 mg/mL, for EO1, EO2 and EO3, respectively, while the MBC values were 12.5 mg/mL, 6.25 mg/mL, and 6.25 mg/mL, respectively. A simplex centroid design was created to analyse the effect of the individual and combined EOs against E. coli. The combined EOs showed enhanced antibacterial activity compared to the individual oils, suggesting a synergistic effect (e.g., trial 9 with an MIC of 0.21 mg/mL), allowing the use of lower EO concentrations and reducing potential negative effects on food flavour and aroma. Additionally, the practical application of investigated EOs (at concentrations twice the MIC) was investigated in raw chicken meat stored at 4 °C for 21 days. The EOs, individually and in combination, effectively extended the shelf life of the meat by inhibiting bacterial growth (total bacterial count of less than 1 × 104 CFU/g in the treated samples compared to 7 × 107 CFU/g in the control on day 21 of storage). The study underlines the potential of C. aurantium EOs as natural preservatives that represent a sustainable and effective alternative to synthetic chemicals in food preservation.