Fungal food spoilage plays a key role in the deterioration of food products, and finding a suitable natural preservative can solve this problem. Therefore, antifungal activity of green mandarin (Citrus reticulata) essential oil (GMEO) in the vapor phase against the growth of Penicillium (P.) expansum and P. chrysogenum inoculated on wheat bread (in situ experiment) was investigated in the current research. The volatile compounds of the GMEO were analyzed by a gas chromatograph coupled to a mass spectrometer (GC–MS), and its antioxidant activity was determined by testing free radical-scavenging capacity (DPPH assay). Moreover, the disc diffusion method was used to analyze the antifungal activity of GMEO in in vitro conditions. The results demonstrate that the Citrus reticulata EO consisted of α-limonene as the most abundant component (71.5%), followed by γ-terpinene (13.9%), and β-pinene (3.5%), and it displayed the weak antioxidant activity with the value of inhibition 5.6 ±0.7%, which corresponds to 103.0 ±6.4 μg TEAC.mL-1. The findings from the GMEO antifungal activity determination revealed that values for the inhibition zone with disc diffusion method ranged from 0.00 ±0.00 (no antifungal effectiveness) to 5.67 ±0.58 mm (moderate antifungal activity). Finally, exposure of Penicillium strains growing on bread to GMEO in vapor phase led to the finding that 250 μL.L-1 of GMEO exhibited the lowest value for mycelial growth inhibition (MGI) of P. expansum (-51.37 ±3.01%) whose negative value reflects even supportive effect of the EO on the microscopic fungus growth. On the other hand, GMEO at this concentration (250 μL.L-1) resulted in the strongest inhibitory action (MGI: 54.15 ±1.15%) against growth of P. chrysogenum. Based on the findings it can be concluded that GMEO in the vapor phase is not an effective antifungal agent against the growth of P. expansum inoculated on bread; however, its antifungal potential manifested against P. chrysogenum suggests GMEO to be an appropriate alternative to the use of chemical inhibitors for bread preservation.
Essential oils (EOs) are complex mixtures of water-vapor aromatic substances (mainly terpenoids, less frequently aromatic and aliphatic compounds) derived from diverse parts of plants in which they determined their pleasant aroma (Denkova-Kostova et al., 2021). They possess a broad range of various biological activities such as antimicrobial, antioxidant, anti-inflammatory, and anticancer activities (Sharifi-Rad et al., 2017) which were documented in many preclinical studies. In addition, their antifungal properties have been screened on a global scale as potential sources of novel antimicrobial compounds, promoting food preservation (Chouhan, Sharma and Guleria, 2017).
Citrus essential oils (EOs) have a volatile fraction usually >90% in which monoterpenes and sesquiterpenes are found with limonene being the major compound (Raspo et al., 2020). From them, mandarin EO is extracted from Citrus reticulata of the Rutaceae family and has some great properties to help relieve stress and digestive problems. Also, it is used to increase circulation to the skin, reducing fluid retention, and to help prevent stretch marks (Fayed, 2009). In general, there are three kinds of mandarin EO, i.e., green, yellow, and red, all derived from the same fruit, but at different stages of maturity. Green mandarin essential oil (GMEO) is generally sharper and with more of a “peel” note compared to red mandarin (Boughendjioua, Mezedjeri and Idjouadiene, 2020). From a chemical profile point of view, the mandarin EO contains α-pinene, β-pinene, camphene, citral, citronellal, γ-terpinolen, geraniol, citric, linalool, methyl myrcene, sabine, and terpineol (Denkova-Kostova et al., 2021). It is well-known for its antibacterial and antifungal actions in a wide spectrum. Indeed, its strong activity against some microorganisms related to food spoilage and food safety including Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus flavus, and P. digitatum was reported (Gao et al., 2010;Tao et al., 2009;Wang et al., 2012).
The major purpose of our study was to evaluate the antifungal potential of GMEO against selected Penicillium (P.) species (P. expansum and P. chrysogenum) using the contact vapor method. Moreover, the chemical composition of the GMEO, as well as its antioxidant properties and antifungal effect in in vitro conditions were established. The obtained findings of the studied GMEO would give a reason for their inclusion in the development of biopreservation strategies for the food industry.
Scientific hypothesis
Since Citrus reticulata essential oil represents a rich source of bioactive monoterpenes, its antifungal potential against Penicillium spp. could be expected.
MATERIAL ANDMETHODOLOGYSamples
Green mandarin essential oil (GMEO; Citrus reticulata) was purchased from Hanus Company (Ltd, Hrochoť, Slovakia).
Wheat bread was obtained from Laboratory of Cereal Technologies (AgroBioTech Research Centre, Slovak University of Agriculture in Nitra).
Chemical
All chemicals were analytical grade, and were purchased from Merck (Darmstadt, Germany) and Sigma Aldrich (Schnelldorf, Germany).
Sabouraud Dextrose Agar (SDA; Schnelldorf, Germany).
Animals and Biological Material
The fungi P. expansum and P. chrysogenum were isolated from grape and bread samples, respectively. Then, they were identified with the MALDI-TOF MS Biotyper and 16S rRNA sequencing.
Instruments
Mass spectrophotometer (MALDI-TOF MS Biotyper, Bruker, USA).
Laboratory MethodsDetermination of volatile compounds
The chemical profile of GMEO was performed using an Agilent 6890N gas chromatograph coupled to quadrupole mass spectrometer 5975B as reported by Valková et al. (2021). The individual volatile constituents of the injected EO samples were identified based on their retention indices (Adams, 2007) and compared with reference spectra (Wiley and NIST databases). The retention indices were experimentally determined using the standard method (Van Den Dool and Kratz, 1963) which included retention times of n-alkanes (C6-C34), injected under the same chromatographic conditions. The percentages of the identified compounds (amounts higher than 0.1%) were derived from their GC peak areas.
Determination of radical scavenging activity
The radical scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) was used to measure the antioxidant activity (AA) of GMEO described previously by Galovičová et al. (2021). The AA was expressed as the percentage of DPPH inhibition, and was calculated according to the formula: (A0 – A1)/A0 × 100; where A0 was the absorbance of DPPH and A1 was the absorbance of the sample. The AA values increased in the following manner: weak (0 – 29%) < medium-strong (30 – 59%) < strong (60 and more %). Moreover, the value of total AA was expressed according to the calibration curve as 1 μg of standard reference Trolox to 1 mL of the GMEO sample (TEAC).
Evaluation of antifungal activity
The evaluation of the antifungal activity of the GMEO was performed using the agar disc diffusion method according to the Valková et al. (2021) with minor modifications. For this purpose, an aliquot of 0.1 mL of fungal in distilled water was inoculated on SDA (60 mm). Subsequently, the discs of filter paper (6 mm) were impregnated with 10 μL of GMEO samples (in four concentrations: 62.5, 125, 250, and 500 μL.L-1), then applied on the SDA surface, and incubated at 25 °C for 5 days. The disks impregnated with ethanol served as negative controls. After incubation, the diameters of the inhibition zones in mm were measured. Each test was repeated three times (one repeat reflected one separate plate). The values of inhibitory activity increased in the following manner: weak antifungal activity (5 – 10 mm) < moderate antifungal activity (5 – 10 mm) < very strong antifungal activity (zone > 15 mm).
Bread making procedure
Wheat bread, as a substrate for fungal growth, was made according to the procedure by Kačániová et al. (2020a) in the Laboratory of Cereal Technologies (AgroBioTech Research Centre, the Slovak University of Agriculture in Nitra).
Antifungal analyses on bread loaves model
First, the bread samples were cut into slices with 150 mm height and placed into 0.5 L sterile glass jars (Bormioli Rocco, Fidenza, Italy). The fungal spores were used for bread inoculation. The GMEO in concentrations of 62.5, 125, 250, and 500 μL.L-1 (diluted in ethyl acetate) were evenly distributed in a volume of 100 μL on a sterile paper–filter disc (6 cm), which was inserted into the cover of the jar, except for the control group. The jars were hermetically closed and kept at 25 ±1 °C for 14 days in the dark (Kačániová et al., 2020a). The size of the microfungal colonies with visible mycelial growth and visible sporulation was evaluated using stereological methods. In this concept, the volume density of the colonies was firstly assessed using ImageJ software (National Institutes of Health, Bethesda, MD, USA), counting the points of the stereological grid hitting the colonies and those falling to the reference space (growth substrate used, i.e., bread). The antifungal activities of the EOs were expressed as the percentage of mycelial growth inhibition (MGI), which was calculated using the formula: MGI = [(C − T)/C] × 100, where C = volume density of the fungal colony in the control group and T = volume density of that in the treatment group (Sempere-Ferre et al., 2021).
Description of the Experiment
Sample preparation: 42
Number of samples analyzed: 42
Number of repeated analyses: 4
Number of experiment replication: 3
Statistical Analysis
The obtained data were statistically evaluated using Prism 8.0.1 (GraphPad Software, San Diego, California, USA). One-way analysis of variance (ANOVA) followed by Tukey’s test was used to evaluate the significance of differences between analyzed groups of samples. The level of significance was set at p <0.05.
RESULTS AND DISCUSSIONChemical composition of GMEO
Although the mode of action of EOs has not been fully elucidated it is well-known that their primary effects are related to their chemical composition (Burt, 2004;Cox and Markham, 2007). Indeed, these compounds, typically monoterpenes or phenylpropanoids, often exhibit antioxidant capacity and also antimicrobial activity against a wide range of bacterial and fungal species (Sikkema, de Bont and Poolman, 1995;Behbani et al., 2017). Moreover, the interaction between the various compounds of EOs can lead to antagonistic, additive, or synergistic effects (Burt, 2004). Therefore, the identification of individual volatile substances may be a useful tool for the characterization of EOs, and may help to understand the key points in their antioxidant and antimicrobial activity, thus being possible to employ either alone or in combination with other additives in food preservation techniques (Viuda-Martos et al., 2007;Miladinovic et al., 2015).
GC-MS analysis was also used in our study to determine the chemical composition of GMEO. It revealed that a total of 28 compounds, accounting for 99.7% of the whole constituents, were identified in the EO chemical profile. The major compound was shown to be α-limonene (71.5%), and other major ones included γ-terpinene (13.9%), β-pinene (3.5%), p-cymene (3.1%), α-pinene (2.6%), and β-myrcene (2.2%), as presented Table 1.
Main volatile compounds of green mandarin essential oil.
Compounds
(%)
α-limonene
71.5
γ-terpinene
13.9
β-pinene
3.5
p-cymene
3.1
α-pinene
2.6
β-myrcene
2.2
α-terpineol
1.0
α-terpinolene
0.7
α-thujene
0.5
n-decanal
0.4
sabinene
0.3
(E)-β-ocimene
0.1
trans-limonene oxide 4-terpinenol
tr
α-copaene
(E)-caryophyllene
(E,E)-α-farnesene
δ-cadinene
TOTAL
99.7
Note: tr – compounds identified in amounts less than 0.1%.
Our results are in agreement with the previous findings reported by Viuda-Martos et al. (2009), who consider α-limonene (74.7%) and γ-terpinene (15.7%) as the major oil compounds of the mandarin EO. The same observation was also demonstrated by Espina et al. (2011) and Denkova-Kostova et al. (2021), who found that the main compound of C. reticulata EO was limonene which comprised 74.4% and 84.88% of the EO, respectively. In contrast to our findings, Yabalak, Eliuz and Nazlı (2021) detected eucalyptol (7.2%), methyl palmitate (3.8%), and α-terpineol (3.7%) as the most represented substances in their C. reticulata EO, whereby α-limonene (71.5%) or γ-terpinene were absent in its chemical profile. However, we assume that the differences in the EO chemical composition between these studies might be due to various factors such as genetic factors (genotype or variety), geographical locations, environmental conditions, season, cultivation practices, fertilizer application, stress during growth or maturity, harvesting time, stage of maturity, as well as processing methods which strongly influenced it (Burt, 2004;Sandeep, Sanghamitra and Sujata, 2015;Srinivasan et al., 2016).
Summary, based on the findings we can propose that the high proportion of monoterpenes (mainly α-limonene, γ-terpinene, and β-pinene) in our analyzed GMEO can predict its promising use as a preservative in the food industry as it was stated in the study by Badawy, Lotfy and Shawir (2020).
Antioxidant activity of GMEO
It is generally known that EOs have antioxidant properties, which are subjected to analyses performed in many scientific papers (Diniz do Nascimento et al., 2020;Kačániová et al., 2020b;Boudiba et al., 2021).
The DPPH method, also used in our study, is considered a simple and sensitive technique applicable to most plant extracts including EOs (Noipa et al., 2011). DPPH is a stable free radical with deep violet color, which accepts an electron or hydrogen radical to create a stable diamagnetic molecule with discoloration. The degree of discoloration indicates the free radical-scavenging potential of the sample (Schaich, Tian and Xie, 2015). Interestingly, employing this assay we have found that values for AA of the EO of C. reticulata were 103.0 ±6.4 μg TEAC.mL-1, with 5.6 ±0.7% free radical-scavenging inhibition linked to a weak AA. Dissimilar to our results, Boudries et al. (2017) reported a higher value of % of inhibition associated with a stronger AA of mandarin EO which was even the highest between all analysed citrus fruit EOs (mandarin, clementin, wilking). Also, the highest DPPH activities (78.0%; 73.32%) of EO from Citrus reticulata were found in the studies by Denkova-Kostova et al. (2021) and Ishfaq et al. (2021), respectively. Most probably, different chemical compositions and amounts of individual constituents (depending on various aforementioned factors) of the mandarin EOs used in our and all mentioned studies could be responsible for the discrepancies in AA of the EOs demonstrated by their results.
<italic>In vitro</italic> antifungal properties of GMEO
Data from the inhibitory effects of GMEO against two tested Penicillium spp. fungi (P. expansum, and P. chrysogenum) assessed by the disc diffusion method are shown in Table 2. Our results revealed that the growth inhibition of fungi strains depends on the concentration of the GMEO applied. In effect, moderate antifungal activity (inhibition zone: 5.67 ±0.58 mm) was observed at the highest concentration (500 μL.L-1) of GMEO against the growth of P. chrysogenum. This effect was statistically different (p <0.05) from those exhibiting at the lowest concentration (62.5 μL.L-1) of the GMEO which showed no inhibitory activity (inhibition zone: 0.00 ±0.00 mm) against this fungus strain. On the other hand, the growth of P. expansum was only weakly inhibited (inhibition zone: 1.67 ±0.58 mm) by GMEO in the concentration of 500 μL.L-1, and this inhibition even significantly differ from those (inhibition zone: 0.00 ±0.00 mm) displayed by remaining concentrations (62.5, 125, 250 μL.L-1) of GMEO.
Antifungal activity of EOs (in vitro).
Fungal strains
The inhibition zones (mm)
GMEO (μL.L-1)
62.5
125
250
500
P. expansum
0.00 ±0.00 a
0.00 ±0.00 a
0.00 ±0.00 a
1.67 ±0.58 b
P. chrysogenum
0.00 ±0.00 a
2.67 ±0.58 b
4.00 ±1.00 b
5.67 ±0.58 b
Note: Means ± standard deviation. Values followed by different superscript within the same row are significantly different (p <0.05). GMEO – Green mandarin essential oil; 00.00 – total growth.
Several scientific studies have demonstrated that citrus EOs have been shown to reduce or completely inhibit the growth of microscopic fungi depending on their concentration (Sharma and Tripathi, 2006;Sharma and Tripathi, 2008). Droby et al. (2008) observed that citrus EOs (mandarin, lemon, grapefruit, and orange) in concentration of 20.0 μL.mL-1 stimulated the growth of P. italicum and P. digitatum. On the other hand, grapefruit EOs (in concentration of 40.0 μL.mL-1) had moderate antifungal activity against P. digitatum. Moreover, it was found that some microscopic fungi can catalyze the conversion of antifungal compounds in various plant extracts (including those obtained in EOs). Such conversion has also been reported for instance in P. digitatum which was able to convert limonene to α-terpineol, cis- and trans-p-menth-2-en-1-ol, neodihydrocarveol and limonene oxide (Tan, Day and Cadwallader, 1998;Demyttenaere, Van Belleghem and De Kimpe, 2001;Badee, Helmy and Morsy, 2011), i.e., to less effective substances related to antifungal activity. Therefore, we assume that a similar type of conversion may explain why GMEO was more powerful against P. chrysogenum as compared to P. expansum, as was reported in our study.
<italic>In situ</italic> antifungal vapor contact assay of GMEO
In general, antifungal agents are used in the food industry for the preservation of food (control natural spoilage processes) or their safety (prevent or control the growth of microorganisms; Shaaban, 2020). As spoilage of bakery products is often caused by microscopic fungi including Penicillium spp. (Salas et al., 2017) the antifungal properties of GMEO in the vapor phase on bread as a substrate for the growth of these species were evaluated in our study. The relative volatilities of the EOs compounds determine the characteristics of their vapors which have impacts on antimicrobial potential (Tullio et al., 2007). Several studies have shown that the vapor phases of EOs are more effective than liquid ones (Soylu, Soylu and Kurt, 2006;Mondello et al., 2009;Tyagi and Malik, 2010). This fact can be attributed to the free adhesion of EOs to the substrate (vapor phase), while in the aqueous phase the lipophilic molecules combine to form micelles suppressing the adhesion of EOs to the substrate (Inouye et al., 2003).
The inhibitory effects of our GMEO on the growth of the Penicillium spp. inoculated on wheat bread are demonstrated in Table 3 and Figure 1. From the results, it can be evident that all GMEO concentrations analyzed (62.5, 125, 250, and 500 μL.L-1) exhibited antifungal potential against P. chrysogenum, whereby the concentration of 250 μL.L-1 showed the best efficiency (54.15 ±1.15%). Moreover, between all concentrations used, statistically significant differences (p <0.05) were noted. Interestingly, the growth of P. expansum was only very weak (3.49 ±1.23%) inhibited by the lowest concentration (62.5 μL.L-1) of GMEO. On the other hand, the remaining concentrations used (125, 250, and 500 μL.L-1) acted proactively on the growth of this fungus which was indicated by the negative values of -11.77 ±0.40, - 51.37 ±3.01, and -15.35 ±0.99%, respectively.
Mycelial growth inhibition of the GMEO.
Fungal strains
MGI (%)
GMEO (μL.L-1)
62.5
125
250
500
P. expansum
3.49 ±1.23 a
-11.77 ±0.40 b
-51.37 ±3.01 c
-15.35 ±0.99 d
P. chrysogenum
14.17 ±0.53 a
20.02 ±2.13 b
54.15 ±1.15 c
45.61 ±0.88 d
Note: Means ± standard deviation. Values followed by different superscript within the same row are significantly different (p <0.05). MGI – Mycelial growth inhibition; GMEO – Green mandarin essential oil; 00.00 – total growth. The negative values indicate a profungal activity against Penicillium strains.
In situ antifungal analyses of bread with Penicillum expansum and Penicillium chrysogenum in vapor phase. Note: 1 – P. chrysogenum; 2 – P. expansum and after their treatment with different GMEO concentrations (A – control; B – 62.5 μL.L-1; C - 125 μL.L-1; D – 250 μL.L-1 and E – 500 μL.L-1).
We hypothesize that the weak antifungal activity of GMEO against P. expansum may be due to the high resistance of this strain (Adams, 2007). Therefore, we assume that GMEO used can be more effective against other species of microscopic fungi as was shown in the case of P. chrysogenum. Interestingly, P. chrysogenum was the most sensitive to the concentration of 250 μL.L-1 of the EO. For this reason, in our further research activities, we will deal with the optimization of GMEO concentration to obtain its highest possible efficiency. Moreover, the results are following our previous researches, in which the antifungal properties of other EOs, such as Citrus aurantium EO or (Kačániová et al., 2020a) coriander EO (Kačániová et al., 2020b), against the fungi of Penicillium spp. analysed were confirmed. These findings are of particular relevance for food production because by introducing GMEO, the contamination with pathogens could be avoided, and the growth of the microscopic fungi could be inhibited, which is primarily important for the food industry (Denkova-Kostova et al., 2021).
CONCLUSION
The aim of the present research was to assess the antifungal activity of GMEO in the vapor phase on the growth of selected Penicillium species inoculated on wheat bread. The chromatography analysis has shown that the major chemical compounds of the EO were α-limonene (71.5%), γ-terpinene (13.9%) and β-pinene (3.5%). The mandarin EO exhibited only weak AA comparable with Trolox as a standard with a value of 103.0 ±6.4 μg.mL-1 for DPPH, reflecting 5.6 ±0.7% of free radical-scavenging inhibition. The antifungal activity of GMEO against the tested fungi was shown to be not effective or moderate in vitro. Similar trend was also found for in situ analysis in which a maximum value for MGI (54.15 ±1.15%) was observed against P. chrysogenum using 250 μL.L-1 of GMEO. Thus, our results pointed to the fact that GMEO has weak both AA and inhibitory action against the growth of P. expansum. However, against P. chrysogenum it can be considered an appropriate alternative to use synthetic inhibitors for the preservation of bakery products such as wheat bread.
Funds:
This work was supported by the grant APVV SK-BY-RD-19-0014 “The formulation of novel compositions and properties study of the polysaccharides based edible films and coatings with antimicrobial and antioxidant plant additives”.
Conflict of Interest:
The authors declare no conflict of interest.
Ethical Statement:
This article does not contain any studies that would require an ethical statement.
AdamsR.P.Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry. USA : Allured Publishing Corporation, Carol Stream, IL. 456 p. ISBN 978-1-932633-11-4.2007BadawyM.E.I.LotfyT.M.R.ShawirS.M.S.Facile synthesis and characterizations of antibacterial and antioxidant of chitosan monoterpene nanoparticles and their applications in preserving minced meat.Int. J. Biol. Macromol.202015612713610.1016/j.ijbiomac.2020.04.04432289415BadeeA.Z.M.HelmyS.A.MorsyN.F.Utilisation of orange peel in the production of α-terpineol by Penicillium digitatum (NRRL 1202).Food Chem.2011126384985410.1016/j.foodchem.2010.11.046BehbahaniB.A.ShahidiF.YazdiF.T.MortazaviS.A.MohebbiM.Antioxidant activity and antimicrobial effect of tarragon (Artemisia dracunculus) extract and chemical composition of its essential oil.J. Food Meas. Charact.201711284786310.1007/s11694-016-9456-3BoudibaS.TamfuA.N.BerkaB.HaniniK.HiounS.AllafK.BoudibaL.CeylanO.Anti-quorum sensing and antioxidant activity of essential oils extracted from juniperus species, growing spontaneously in Tebessa Region (East of Algeria).Nat. Prod. Commun.202116611110.1177/1934578X211024039BoudriesH.LoupassakiS.Ladjal EttoumiY.SouaguiS.Bachir BeyM.NabetN.ChikhounneA.MadaniK.ChibaneM.Chemical profile, antimicrobial and antioxidant activities of Citrus reticulata and Citrus clementina (L.) essential oils.Int. Food Res. J.201724417821792BoughendjiouaH.MezedjeriN.E.H.IdjouadieneI.2020Chemical constituents of Algerian mandarin (Citrus reticulata) essential oil by GC-MS and FT-IR analysis.33419720110.2478/cipms-2020-0032BurtS.Essential oils: their antibacterial properties and potential applications in foods--a review.Int. J. Food Microbiol.200494322325310.1016/j.ijfoodmicro.2004.03.02215246235ChouhanS.SharmaK.GuleriaS.Antimicrobial activity of some essential oils—present status and future perspectives.Medicines (Basel)2017435810.3390/medicines403005828930272CoxS.D.MarkhamJ.L.Susceptibility and intrinsic tolerance of Pseudomonas aeruginosa to selected plant volatile compounds.J. Appl. Microbiol.2007103493093610.1111/j.1365-2672.2007.03353.x17897196DemyttenaereJ.C.Van BelleghemK.De KimpeN.Biotransformation of (R)-(+)- and (S)-(-)-limonene by fungi and the use of solid phase microextraction for screening.Phytochemistry200157219920810.1016/S0031-9422(00)00499-411382235Denkova-KostovaR.TenevaD.TomovaT.GoranovB.DenkovaZ.ShopskaV.SlavchevA.Hristova-IvanovaY.Chemical composition, antioxidant and antimicrobial activity of essential oils from tangerine (Citrus reticulata L.), grapefruit (Citrus paradisi L.), lemon (Citrus lemon L.) and cinnamon (Cinnamomum zeylanicum Blume).Z. Naturforsch. C J. Biosci.2020765-617518510.1515/znc-2020-012633909955Diniz do NascimentoL.MoraesA.A.B.CostaK.S.D.Pereira GalúcioJ.M.TaubeP.S.CostaC.M.L.Neves CruzJ.de Aguiar AndradeE.H.FariaL.J.G.Bioactive natural compounds and antioxidant activity of essential oils from spice plants: New findings and potential applications.Biomolecules202010798810.3390/biom1007098832630297DrobyS.A.M.I.R.EickA.MacarisinD.CohenL.RafaelG.I.N.A.T.StangeR.ShapiraR.Role of citrus volatiles in host recognition, germination and growth of Penicillium digitatum and Penicillium italicum.Postharvest Biol. Technol.200849338639610.1016/j.postharvbio.2008.01.016EspinaL.SomolinosM.LoránS.ConchelloP.GarcíaD.PagánR.Chemical composition of commercial citrus fruit essential oils and evaluation of their antimicrobial activity acting alone or in combined processes.Food Control201122689690210.1016/j.foodcont.2010.11.021FayedS.A.Antioxidant and anticancer activities of Citrus reticulate (Petitgrain Mandarin) and Pelargonium graveolens (Geranium) essential oils.Res. J. Agric. Biol. Sci.200955740747GalovičováL.BorotováP.ValkováV.VukovicN.L.VukicM.TerentjevaM.ŠtefánikováJ.ĎúranováH.KowalczewskiP.L.KačániováM.Thymus serpyllum Essential Oil and Its Biological Activity as a Modern Food Preserver.Plants2021107141610.3390/plants1007141634371619GaoY.TaoN.LiuY.GeF.FengB.Antimicrobial Activity of the Essential Oil from the Peel of Ponkan (Citrus reticulate Blanco).J. Essent. Oil-Bear. Plants201013223023610.1080/0972060X.2010.10643817InouyeS.AbeS.YamaguchiH.AsakuraM.2003Comparative study of antimicrobial and cytotoxic effects of selected essential oils by gaseous and solution contacts.International Journal of Aromatherapy131334110.1016/S0962-4562(03)00057-2IshfaqM.AkhtarB.MuhammadF.SharifA.AkhtarM.F.HamidI.SohailK.MuhammadH.Antioxidant and Wound Healing Potential of Essential Oil from Citrus reticulata Peel and Its Chemical Characterization.Curr. Pharm. Biotechnol.20212281114112110.2174/138920102199920091810212332957881KačániováM.GalovičováL.IvanišováE.VukovicN. L.ŠtefánikováJ.ValkováV.BorotováP.ŽiarovskáJ.TerentjevaM.FelšöciováS.TvrdáE.2020bntioxidant, antimicrobial and antibiofilm activity of coriander (Coriandrum sativum L.) essential oil for its application in foods.Foods9328210.3390/foods9030282KačániováM.TerentjevaM.GalovičováL.IvanišováE.ŠtefánikováJ.ValkováV.BorotováP.KowalczewskiP.L.KunováS.FelšöciováS.TvrdáE.ŽiarovskáJ.Benda ProkeinováR.VukovicN.Biological activity and antibiofilm molecular profile of Citrus aurantium essential oil and its application in a food model.Molecules2020a2517395610.3390/molecules2517395632872611Leyva SalasM.MounierJ.ValenceF.CotonM.ThierryA.CotonE.Antifungal microbial agents for food biopreservation—a review.Microorganisms2017533710.3390/microorganisms503003728698479MiladinovicD.L.IlicB.S.MatejicJ.S.RandjelovicV.N.NikolicD.M.Chemical composition of the essential oil of Geum coccineum.Chem. Nat. Compd.201551478578610.1007/s10600-015-1412-7MondelloF.GirolamoA.ScaturroM.RicciM.L.Determination of Legionella pneumophila susceptibility to Melaleuca alternifolia Cheel (tea tree) oil by an improved broth micro-dilution method under vapour controlled conditions.J. Microbiol. Methods200977224324810.1016/j.mimet.2009.02.01219264101NoipaT.SrijaranaiS.TuntulaniT.NgeontaeW.New approach for evaluation of the antioxidant capacity based on scavenging DPPH free radical in micelle systems.Food Res. Int.201144379880610.1016/j.foodres.2011.01.034RaspoM.A.VignolaM.B.AndreattaA.E.JulianiH.R.Antioxidant and antimicrobial activities of citrus essential oils from Argentina and the United States.Food Biosci.20203610065110.1016/j.fbio.2020.100651SandeepI.S.SanghamitraN.SujataM.Differential effect of soil and environment on metabolic expression of turmeric (Curcuma longa cv. Roma).Indian J. Exp. Biol.201553640641126155681SchaichK.M.TianX.XieJ.Hurdles and pitfalls in measuring antioxidant efficacy: A critical evaluation of ABTS, DPPH, and ORAC assays.J. Funct. Foods20151411112510.1016/j.jff.2015.01.043Sempere-FerreF.AsamarJ.CastellV.RosellóJ.SantamarinaM.P.Evaluating the Antifungal Potential of Botanical Compounds to Control Botryotinia fuckeliana and Rhizoctonia solani.Molecules2021269247210.3390/molecules2609247233922682ShaabanH.A.Essential Oil as Antimicrobial Agents: Efficacy, Stability, and Safety Issues for Food Application.Essential Oils-Bioactive Compounds, New Perspectives and Applications.202013310.5772/intechopen.92305Sharifi-RadJ.SuredaA.TenoreG.C.DagliaM.Sharifi-RadM.ValussiM.TundisR.Sharifi-RadM.LoizzoM.R.AdemiluyiA.O.Sharifi-RadR.AyatollahiS.A.IritiM.Biological activities of essential oils: From plant chemoecology to traditional healing systems.Molecules20172217010.3390/molecules2201007028045446SharmaN.TripathiA.Fungitoxicity of the essential oil of Citrus sinensis on post-harvest pathogens.World J. Microbiol. Biotechnol.200622658759310.1007/s11274-005-9075-3SharmaN.TripathiA.Effects of Citrus sinensis (L.) Osbeck epicarp essential oil on growth and morphogenesis of Aspergillus niger (L.) Van Tieghem.Microbiol. Res.20081633337344SikkemaJ.de BontJ.A.PoolmanB.Mechanisms of membrane toxicity of hydrocarbons.Microbiol. Rev.199559220122210.1128/mr.59.2.201-222.19957603409SoyluE.M.SoyluS.KurtS.Antimicrobial activities of the essential oils of various plants against tomato late blight disease agent Phytophthora infestans.Mycopathologia2006161211912810.1007/s11046-005-0206-z16463095SrinivasanV.ThankamaniC.K.DineshR.KandiannanK.ZachariahT.J.LeelaN.K.HamzaS.AnshaO.Nutrient management systems in turmeric: Effects on soil quality, rhizome yield and quality.Ind. Crops Prod.20168524125010.1016/j.indcrop.2016.03.027TanQ.DayD.F.CadwalladerK.R.Bioconversion of (R)-(+)-limonene by P. digitatum (NRRL 1202).Process Biochem.1998331293710.1016/S0032-9592(97)00048-4TaoN.G.LiuY.J.TangY.F.ZhangJ.H.ZhangM.L.ZengH.Y.Essential oil composition and antimicrobial activity of Citrus reticulata.Chem. Nat. Compd.2009453437438TullioV.NostroA.MandrasN.DugoP.BancheG.CannatelliM.A.CuffiniA.M.AlonzoV.CarloneN.A.Antifungal activity of essential oils against filamentous fungi determined by broth microdilution and vapour contact methods.J. Appl. Microbiol.200710261544155010.1111/j.1365-2672.2006.03191.x17578419TyagiA.K.MalikA.Antimicrobial action of essential oil vapours and negative air ions against Pseudomonas fluorescens.Int. J. Food Microbiol.2010143320521010.1016/j.ijfoodmicro.2010.08.02320850191ValkováV.ĎúranováH.GalovičováL.VukovicN.L.VukicM.KačániováM.In Vitro Antimicrobial Activity of Lavender, Mint, and Rosemary Essential Oils and the Effect of Their Vapours on Growth of Penicillium spp. in a Bread Model System.Molecules20212613385910.3390/molecules2613385934202776VandendoolH.KratzP.D.A Generalization of the Retention Index System Including Linear Temperature Programmed Gas-Liquid Partition Chromatography.J. Chromatogr. A196311463471Viuda-MartosM.Ruiz-NavajasY.Fernández-LópezJ.Pérez-ÁlvarezJ. A.2009Chemical composition of mandarin (C. reticulata L.), grapefruit (C. paradisi L.), lemon (C. limon L.) and orange (C. sinensis L.) essential oils.Journal of Essential Oil Bearing Plants12223624310.1080/0972060X.2009.10643716Viuda-MartosM.Ruíz-NavajasY.Fernández-LópezJ.Pérez-ÁlvarezJ.A.Chemical composition of the essential oils obtained from some spices widely used in Mediterranean region.Acta Chim. Slov.2007544921926WangH.TaoN.HuangS.LiuY.Effect of Shatangju (Citrus reticulata Blanco) essential oil on spore germination and mycelium growth of Penicillium digitatum and P. italicum.J. Essent. Oil-Bear. Plants201215571572310.1080/0972060X.2012.10644111YabalakE.Erdoğan EliuzE.A.NazlıM.D.Evaluation of Citrus reticulata essential oil: Chemical composition and antibacterial effectiveness incorporated gelatin on E. coli and S. aureus.Int. J. Environ. Health Res.202111010.1080/09603123.2021.187205933427494