Illicium verum essential oil, a potential natural fumigant in preservation of lotus seeds from fungal contamination

Biological Activity and Phytochemical Characteristics of Star Anise (Illicium verum) Essential Oil and Its Anti-Salmonella Activity on Sous Vide Pumpkin Model

Illicium verum, commonly known as star anise, represents one of the notable botanical species and is recognized for its rich reservoir of diverse bioactive compounds. Beyond its culinary application as a spice, this plant has been extensively utilized in traditional medicine. Given the contemporary emphasis on incorporating natural resources into food production, particularly essential oils, to enhance sensory attributes and extend shelf life, our study seeks to elucidate the chemical composition and evaluate the antibacterial (in vitro, in situ) and insecticidal properties of Illicium verum essential oil (IVEO). Also, microbiological analyses of pumpkin sous vide treated with IVEO after inoculation of Salmonella enterica were evaluated after 1 and 7 days of study. GC/MS analysis revealed a significantly high amount of (E)-anethole (88.4%) in the investigated EO. The disc diffusion method shows that the antibacterial activity of the IVEO ranged from 5.33 (Streptococcus constellatus) to 10.33 mm (Citrobacter freundii). The lowest minimal inhibition concentration was found against E. coli and the minimum biofilm inhibition concertation was found against S. enterica. In the vapor phase, the best antimicrobial activity was found against E. coli in the pears model and against S. sonei in the beetroot model. The application of the sous vide method in combination with IVEO application decreased the number of microbial counts and eliminated the growth of S. enterica. The most isolated microbiota identified from the sous vide pumpkin were Bacillus amyloliquefaciens, B. cereus, B. licheniformis, and Ralstonia picketii. Modifications to the protein composition of biofilm-forming bacteria S. enterica were suggested by the MALDI TOF MS instigations. The IVEO showed insecticidal potential against Harmonia axyridis. Thanks to the properties of IVEO, our results suggest it can be used in the food industry as a natural supplement to extend the shelf life of foods and as a natural insecticide.

Adulticidal synergy of two plant essential oils and their major constituents against the housefly Musca domestica and bioassay on non-target species

Single and mixture formulations of lemongrass (Cymbopogon citratus (DC.) Stapf.) and star anise (Illicium verum (J. Presl.)) essential oils (EOs) and their major constituents were assayed for their adulticidal activities against housefly, Musca domestica L., and two non-target species, stingless bee (Tetragonula pegdeni Schwarz) and guppy (Poecilia reticulata Peters). The efficacies of the mixture formulations were compared against those of the single formulations and 1.0% α-cypermethrin, a common synthetic insecticide. GC-MS analysis found that the major constituent of lemongrass EO was geranial (45.23%), and that of star anise EO was trans-anethole (93.23%). Almost all mixture formulations were more effective in adulticidal activity against housefly adults than single formulations and 1.0% α-cypermethrin. A mixture of 1.0% lemongrass EO + 1.0% trans-anethole exhibited the strongest synergistic insecticidal activity with a 100% mortality rate (KT50 of 3.2 min and LT50 of 0.07 h). The relative percentage increase in mortality rate over single formulations was between 1.6 and 91.9%. In addition, it was three times more effective than 1.0% α-cypermethrin. To find the mechanism of adulticidal action, scanning electron microscopy (SEM) was done to find morphological aberrations, such as antennal and mouthpart aberrations, after the houseflies were treated with 1.0% lemongrass EO + 1.0% trans-anethole. The aberrations included deformed and abnormal shape of arista and flagellum, change in labellum pigmentation, and damage to pseudotracheae. Regarding toxicity against non-target species, all single and mixture formulations were not toxic to the two non-target species, while 1.0% α-cypermethrin was highly toxic. To conclude, a mixture of 1.0% lemongrass EO + 1.0% trans-anethole can be an excellent, natural, sustainable housefly adulticidal agent.

Antifungal mechanism of rose, mustard, and their blended essential oils against Cladosporium allicinum isolated from Xinjiang naan and its storage application

AIMS

To reveal the inhibition mechanism of rose, mustard, and blended essential oils against Cladosporium allicinum isolated from Xinjiang naan, and investigate the effect of the three essential oils on oxidative damage and energy metabolism.

METHODS AND RESULTS

Rose and mustard essential oils significantly inhibited mycelial growth and spore viability in a dose-dependent relationship. After essential oil treatment, the cell membrane permeability was altered, and significant leakage of intracellular proteins and nucleic acids occurred. SEM observations further confirmed the disruption of cell structure. ROS, MDA, and SOD measurements indicated that essential oil treatment induced a redox imbalance in C. allicinum, leading to cell death. As for energy metabolism, essential oil treatment significantly reduced Na+K+-ATPase, Ca2+Mg2+-ATPase, MDH activity, and CA content, impairing metabolic functions. Finally, storage experiments showed that all three essential oils ensured better preservation of naan, with mustard essential oil having the best antifungal effect.

CONCLUSIONS

Rose and mustard essential oils and their blends can inhibit C. allicinum at multiple targets and pathways, destroying cell morphological structure and disrupting metabolic processes.

Current status, technology, regulation and future perspectives of essential oils usage in the food and drink industry

Nowadays, essential oils (EOs) have a wide use in many applications such as in food, cosmetics, pharmaceutical and animal feed products. Consumers' preferences concerning healthier and safer foodstuffs lead to an increased demand for natural products, in replacement of synthetic substances, used as preservatives, flavourings etc. EOs, besides being safe, are promising alternatives as natural food additives, and much research has been carried out on their antioxidant and antimicrobial activity. The initial purpose of this review is to discuss conventional and 'green' extraction techniques along with their basic mechanism for the isolation of EOs from aromatic plants. This review aims to provide a broad overview of the current knowledge about the chemical constitution of EOs while considering the existence of different chemotypes, since bioactivity is attributed to the chemical composition - qualitative and quantitative - of EOs. Although the food industry primarily uses EOs as flavourings, an overview on recent applications of EOs in food systems and active packaging is provided. EOs exhibit poor solubility in water, oxidation susceptibility, negative organoleptic effect and volatility, restricting their use. Encapsulation techniques have been proven to be one of the best approaches to preserve the biological activities of EOs and minimize their effects on food sensory qualities. Herein, different encapsulation techniques and their basic mechanism for loading EOs are discussed. EOs are highly accepted by consumers, who are often under the misconception that 'natural' means safe. This is, however, an oversimplification, and the possible toxicity of EOs should be taken into consideration. Thus, in the final section of the current review, the focus is on current EU legislation, safety assessment and sensory evaluation of EOs. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A Comprehensive Review of the Pharmacology, Chemistry, Traditional Uses and Quality Control of Star Anise (Illicium verum Hook. F.): An Aromatic Medicinal Plant

Illicium verum Hook. F., also known as star anise, is one of the most important plants of the genus Anise in the family Magnoliaceae. I. verum not only has the functions of warming Yang, dispersing cold, regulating Qi and relieving pain but can also be used as a condiment to increase flavor as well as reconcile and remove fish smells. Currently, 201 chemical constituents have been identified from star anise; among these, star anise oil and shikimic acid are the two most widely used and studied chemical components in star anise, with the oil accounting for a large proportion of the total. This review integrates, classifies and updates studies related to the botany, pharmacology, phytochemistry, traditional and modern uses and quality control of star anise, with a special reference to its phytochemical composition and pharmacological activity. It will provide a reference for further research on this important medicinal plant. In addition, the broad applications and research profiles of star anise essential oil and shikimic acid are highlighted. Our review indicates that the research prospects regarding star anise are very broad and worthy of further investigation.

Safety and efficacy of a feed additive consisting of a fraction of the essential oil from the fruit and leaves of Illicium verum Hook.f. (star anise terpenes) for use in all animal species (FEFANA asbl)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a fraction of the essential oil from the fruit and leaves of Illicium verum Hook.f. (star anise terpenes), when used as a feed additive for all animal species. The additive contains up to 25% estragole by specification and is obtained by a manufacturing process which results in the enrichment of this genotoxic carcinogen. This is not in line with the principles outlined in the general approach to assess the safety for the target species of botanical preparations which contain compounds that are genotoxic and/or carcinogenic when used as feed additives. Therefore, the FEEDAP Panel considered it was inappropriate to perform an assessment of the safety and efficacy of star anise terpenes for its use as a feed additive.

Safety and efficacy of a feed additive consisting of an essential oil derived from the fruit of Illicium verum Hook.f. (star anise oil) for use in all animal species (FEFANA asbl)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of star anise oil from the fruit (without or with the presence of plant leaves) of Illicium verum Hook.f., when used as a sensory additive in feed and water for drinking for all animal species. For long-living and reproductive animals, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) considered of low concern the use of the additive in complete feed at 0.6 mg/kg for laying hens and rabbits, 1.0 mg/kg for sows and dairy cows, 1.6 mg/kg for sheep/goats, horses and cats, 1.9 mg/kg for dogs and 6.5 mg/kg for ornamental fish. For short-living animals, the Panel had no safety concern when the additive is used at 83.3 mg/kg for veal calves, 73.3 mg/kg for sheep/goats, cattle for fattening and horses for meat production, 83.8 mg/kg for salmonids, 24.8 mg/kg for turkeys for fattening, 18.5 mg/kg chickens for fattening, 33.3 mg/kg for piglets, 40 mg/kg for pigs for fattening and 29.3 mg/kg for rabbits for meat production. These conclusions were extrapolated to other physiologically related species. For any other species, the additive was considered of low concern at 0.6 mg/kg. The use of star anise oil in animal feed is expected to be of no concern for consumers and for the environment. The additive under assessment should be considered as an irritant to skin and eyes, and as a dermal and respiratory sensitiser. Due to the high concentration of estragole (≥ 1%), the additive is classified as suspected of causing genetic defects and of causing cancer and should be handled accordingly. Since the fruit of I. verum and its preparations are recognised to flavour food and their function in feed would be the same, no further demonstration of efficacy was necessary.

Lacticaseibacillus rhamnosus C1 effectively inhibits Penicillium roqueforti: Effects of antimycotic culture supernatant on toxin synthesis and corresponding gene expression

Recently, consumers are increasingly concerned about the contamination of food by molds and the addition of chemical preservatives. As natural and beneficial bacteria, probiotics are a prospective alternative in food conservation because of their antimycotic activities, although the mechanism has not been explained fully at the level of metabolites. This study aimed at investigating the antifungal activities and their mechanisms of five potential probiotic strains (Lacticaseibacillus rhamnosus C1, Lacticaseibacillus casei M8, Lactobacillus amylolyticus L6, Schleiferilactobacillus harbinensis M1, and Limosilactobacillus fermentum M4) against Penicillium roqueforti, the common type of mold growth on the bread. Results showed that C1 emerged the strongest effectiveness at blocking mycelium growth, damaging the morphology of hyphae and microconidia, decreasing DNA content and interfering in the synthesis of the fungal toxins patulin, roquefortine C and PR-toxin, as well as downregulating the expression of key genes associated with the toxin biosynthesis pathways. Further metabonomic investigation revealed that protocatechuic acid with the minimum inhibitory concentration of 0.40 mg/mL, may be most likely responsible for positively correlated with the antimycotic effects of C1. Thus, C1 is expected to be both a potentially greatly efficient and environmental antimycotic for controlling P. roqueforti contamination in foods.

Potential application of lactic acid bacteria in the biopreservation of red grape from mycotoxigenic fungi

BACKGROUND

Filamentous fungi are the main contamination agent in the viticultural sector. Use of synthetic fungicides is the regular answer to these contaminations. Nevertheless, because of several problems associated with the use of synthetic compounds, the industry demands new and safer methods. In the present work, the biopreservation potential of four lactic acid bacteria (LAB) strains was studied against the principal grape contaminant fungi.

RESULTS

Agar diffusion test evidenced that all four culture-free supernatant (CFS) had antifungal properties against all tested fungi. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) test values evidenced that media fermented by the Lactobacillus plantarum E3 and Lactobacillus plantarum E4 strains showed the highest antifungal activity, resulting in an MFC from 6.3 to 100 g L^-1 . Analysis of CFS evidenced the presence of different antifungal compounds, such as lactic acid, phenyllactic acid and pyrazines. In tests on red grapes, an average reduction of 1.32 log₁₀ of the spores per gram of fruit was achieved by all CFS in grapes inoculated with Aspergillus ochraceus and by 0.94 log₁₀ for L. plantarum E3 CFS against Botrytis cinerea.

CONCLUSION

The antifungal activity of the fermented CFS by L. plantarum E3 reduced the growth of B. cinerea and A. ochraceus in grapes, which are the main contaminant and main producer of ochratoxin A in these crops, respectively. Therefore, based on the results obtained in this work, use of the strain L. plantarum E3 could be an interesting option for the biopreservation of grapes. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Essential Oil Nanoemulsion as Eco-Friendly and Safe Preservative: Bioefficacy Against Microbial Food Deterioration and Toxin Secretion, Mode of Action, and Future Opportunities

Microbes are the biggest shareholder for the quantitative and qualitative deterioration of food commodities at different stages of production, transportation, and storage, along with the secretion of toxic secondary metabolites. Indiscriminate application of synthetic preservatives may develop resistance in microbial strains and associated complications in human health with broad-spectrum environmental non-sustainability. The application of essential oils (EOs) as a natural antimicrobial and their efficacy for the preservation of foods has been of present interest and growing consumer demand in the current generation. However, the loss in bioactivity of EOs from fluctuating environmental conditions is a major limitation during their practical application, which could be overcome by encapsulating them in a suitable biodegradable and biocompatible polymer matrix with enhancement to their efficacy and stability. Among different nanoencapsulated systems, nanoemulsions effectively contribute to the practical applications of EOs by expanding their dispersibility and foster their controlled delivery in food systems. In line with the above background, this review aims to present the practical application of nanoemulsions (a) by addressing their direct and indirect (EO nanoemulsion coating leading to active packaging) consistent support in a real food system, (b) biochemical actions related to antimicrobial mechanisms, (c) effectiveness of nanoemulsion as bio-nanosensor with large scale practical applicability, (d) critical evaluation of toxicity, safety, and regulatory issues, and (e) market demand of nanoemulsion in pharmaceuticals and nutraceuticals along with the current challenges and future opportunities.

Essential oils and their nanoformulations as green preservatives to boost food safety against mycotoxin contamination of food commodities: a review

Postharvest food spoilage due to fungal and mycotoxin contamination is a major challenge in tropical countries, leading to severe adverse effects on human health. Because of the negative effects of synthetic preservatives on both human health and the environment, it has been recommended that chemicals that have a botanical origin, with an eco-friendly nature and a favorable safety profile, should be used as green preservatives. Recently, the food industry and consumers have been shifting drastically towards green consumerism because of their increased concerns about health and the environment. Among different plant-based products, essential oils (EOs) and their bioactive components are strongly preferred as antimicrobial food preservatives. Despite having potent antimicrobial efficacy and preservation potential against fungal and mycotoxin contamination, essential oils and their bioactive components have limited practical applicability caused by their high volatility and their instability, implying the development of techniques to overcome the challenges associated with EO application. Essential oils and their bioactive components are promising alternatives to synthetic preservatives. To overcome challenges associated with EOs, nanotechnology has emerged as a novel technology in the food industries. Nanoencapsulation may boost the preservative potential of different essential oils by improving their solubility, stability, and targeted sustainable release. Nanoencapsulation of EOs is therefore currently being practiced to improve the stability and bioactivity of natural products. The present review has dealt extensively with the application of EOs and their nanoformulated products encapsulated in suitable polymeric matrices, so as to recommend them as novel green preservatives against foodborne molds and mycotoxin-induced deterioration of stored food commodities. © 2021 Society of Chemical Industry.

New Determination Methods, Toxic Mechanisms, and Control Strategies (Preface to the special issue of Food and Chemical Toxicology on the Outcomes of Mycotoxins in Food)

The special issue "Mycotoxins in Food: New Determination Methods, Toxic Mechanisms, and Control Strategies" in Food and Chemical Toxicology contains 28 articles on current hot topics in mycotoxins, including deoxynivalenol, T-2 toxin, and fumonisins. Intestinal toxicity, immune toxicity, and oxidative stress are especially concerned by researchers in this special issue; moreover, mycotoxin detoxification and exposure and assessments in humans are reported in this context. All the new results in this special issue will help to further understand the toxic mechanisms of mycotoxins and cast new light for the control of mycotoxin contamination.

Essential Oils and Their Application in Food Safety

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 solubility, and high instability. The recent application of different delivery strategies viz. nanoencapsulation, active packaging, and polymer-based coating effectively addressed these challenges and improved the bioefficacy and controlled release of essential oils. This article provides an overview of essential oils for the preservation of stored foods against bacteria, fungi, and mycotoxins, along with the specialized mechanism of action and technological advancement by using different delivery systems for their effective application in food and agricultural industries smart green preservative.

Antifungal Activity of Essential Oil From Zanthoxylum armatum DC. on Aspergillus flavus and Aflatoxins in Stored Platycladi Semen

The major objective of this study was to evaluate the inhibitory effect of essential oil (EO) from Zanthoxylum armatum DC. on Aspergillus flavus. The chemical composition of the EO was identified by gas chromatography–mass spectrometer. The minimum inhibitory concentration (MIC) of EO was investigated by liquid fermentation. The morphology, colony number, and aflatoxin content of A. flavus in platycladi semen were investigated by stereomicroscopy, scanning electron microscopy, plate counting, and high-performance liquid chromatography. The results indicated that the MIC of EO was 0.8 μL⋅mL^–1, and the main components were β-phellandrene (7.53%), D-limonene (13.24%), linalool (41.73%), terpinen-4-ol (5.33%), and trans-nerolidol (6.30%). After the EO fumigated the platycladi semen, the growth of A. flavus slowed, and the mycelium shrank considerably. The number of colonies after EO treatment at room temperature and cold storage was significantly reduced, the inhibition effect was better under cold storage, and the aflatoxin B1 content did not exceed the standard within 100 days. Therefore, this study demonstrated the good potential of A. flavus growth inhibition during the storage of platycladi semen.

Nanoencapsulation of essential oils and their bioactive constituents: A novel strategy to control mycotoxin contamination in food system

Spoilage of food by mycotoxigenic fungi poses a serious risk to food security throughout the world. In view of the negative effects of synthetic preservatives, essential oils (EOs) and their bioactive constituents are gaining momentum as suitable substitute to ensure food safety by controlling mycotoxins. However, despite their proven preservative potential against mycotoxins, the use of EOs/bioactive constituents in real food system is still restricted due to instability caused by abiotic factors and negative impact on organoleptic attributes after direct application. Nanoencapsulation in this regard could be a promising approach to address these problems, since the process can increase the stability of EOs/bioactive constituents, barricades their loss and considerably prevent their interaction with food matrices, thus preserving their original organoleptic qualities. The aim of this review is to provide wider and up-to-date overview on recent advances in nanoencapsulation of EOs/bioactive constituents with the objective to control mycotoxin contamination in food system. Further, the information on polymer characteristics, nanoencapsulation techniques, factors affecting the nanoencapsulation, applications of nanoencapsulated formulations, and characterization along with the study on their release kinetics and impacts on organoleptic attributes of food are discussed. Finally, the safety aspects of nanoencapsulated formulations for their safe utilization are also explored.

Effect of estragole over the RN4220 Staphylococcus aureus strain and its toxicity in Drosophila melanogaster

Among the bacterial resistance mechanisms, efflux pumps are responsible for expelling xenobiotics, including bacterial cell antibiotics. Given this problem, studies are investigating new alternatives for inhibiting bacterial growth or enhancing the antibiotic activity of drugs already on the market. With this in mind, this study aimed to evaluate the antibacterial activity of Estragole against the RN4220 Staphylococcus aureus strain, which carries the MsrA efflux pump, as well as Estragole's toxicity in the Drosophila melanogaster arthropod model. The broth microdilution method was used to perform the Minimum Inhibitory Concentration (MIC) tests. Estragole was used at a Sub-Inhibitory Concentration (MIC/8) in association with erythromycin and ethidium bromide to assess its combined effect. As for Estragole's toxicity evaluation over D. melanogaster, the fumigation bioassay and negative geotaxis methods were used. The results were expressed as an average of sextuplicate replicates. A Two-way ANOVA followed by Bonferroni's post hoc test was used. The present study demonstrated that Estragole did not show a direct antibacterial activity over the RN4220 S. aureus strain, since it obtained a MIC ≥1024 μg/mL. The association of estragole with erythromycin demonstrated a potentiation of the antibiotic effect, reducing the MIC from 512 to 256 μg/mL. On the other hand, when estragole was associated with ethidium bromide (EtBr), an antagonism was observed, increasing the MIC of EtBr from 32 to 50.7968 μg/mL, demonstrating that estragole did not inhibited directly the MsrA efflux pump mechanism. We conclude that estragole has no relevant direct effect over bacterial growth, however, when associated with erythromycin, this reduced its MIC, potentiating the effect of the antibiotic.