Figure 1 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Time to reach 40% decay of oranges inoculated with P. digitatum and dipped with irradiated (Ir) and non-irradiated (NIr) orange EO and citral. The value for each treatment is the mean of nine treatment units (three replicates x three batches of fruit). The bars on each treatment are the mean standard errors. Different letters indicate a significant difference between treatments at p = 0.05.
Source publication
The effect of UV-C irradiation on antifungal properties of orange essential oil (EO) against Penicillium digitatum in inoculated Navel oranges was examined. The UV-C irradiation of orange EO resulted in a 20% loss of the major constituent, limonene, and the generation of three hydroperoxide oxidation products, (2S,4R)-p-mentha-6,8-diene-2-hydropero...
Contexts in source publication
Context 1
... storage life, as the time taken for 40% of the fruit in each treatment to show a decay lesion diameter ≥4 mm, is presented in Figure 1. This shows firstly, that there was no significant difference between the time to 40% decay for the fruit dipped in any concentration of non-irradiated orange EO and the untreated control. ...
Context 2
... enhanced antimicrobial activity of the irradiated orange EO is attributed to the presence of limonene hydroperoxide derivatives, which Ben-Yehoshua [16] has claimed in a patent to reduce P. digitatum induced decay in kumquat and lemon fruits. The data presented in Figure 1 also show that dipping oranges in 1000 µL L −1 non-irradiated citral significantly delayed the onset of P. digitatum decay and was about twice as effective as dipping in the irradiated 4000 µL L −1 orange EO. This observation is consistent with Ben-Yehoshua et al. [23] who reported that citral extracted from lemon peel displayed a strong inhibitory activity against P. digitatum when applied at 2000 µL L −1 to mature green lemons. ...
Context 3
... the level of inhibition was not as high as that achieved with the non-irradiated citral, orange EO had a significantly commercial advantage of not generating any visible skin damage without the need for an ethanolic dip solution. Given the ready availability of orange skin tissue as a processing waste product and the ability to use the EO in an aqueous solution, it would seem worthwhile to conduct further studies to determine if other methods or combinations of methods, such as radiation, heat, oxygen, and water, could enhance the antimicrobial The data presented in Figure 1 also show that dipping oranges in 1000 µL L −1 non-irradiated citral significantly delayed the onset of P. digitatum decay and was about twice as effective as dipping in the irradiated 4000 µL L −1 orange EO. This observation is consistent with Ben-Yehoshua et al. [23] who reported that citral extracted from lemon peel displayed a strong inhibitory activity against P. digitatum when applied at 2000 µL L −1 to mature green lemons. ...
Citations
... Owing to the poor photostability of CT, it is particularly important to develop pesticide formulations with UV resistance to minimize the decomposition and enhance the utilization efficiency of CT. [45][46][47][48] As shown in Figure 5(A) and Table 3, the CT decomposition rate rapidly reached 15.73% after 1 h of UV radiation treatment. Then, after 48 h, the CT decomposition rate in both CT@HMS and CT@HMS@CH/TA was less than that of CT alone, wileyonlinelibrary.com/journal/ps ...
BACKGROUND
Owing to their surface modifiability, smart mesoporous silica nanoparticles (MSNs) can be designed to respond to plant disease‐microenvironmental stimuli, thereby achieving on‐demand release of active ingredients to control disease by effectively improving citral (CT) stability.
RESULTS
A pH/chitinase dual stimuli‐responsive essential oil‐delivery system (CT@HMS@CH/TA) was successfully fabricated by encapsulating CT in hollow mesoporous silica (HMS), and coating with tannic acid (TA) and chitosan (CH) within HMS by using the layer‐by‐layer assembly technique (LbL). CT@HMS@CH/TA with an average particle size of 125.12 ± 0.12 nm and a hollow mesoporous nanostructure showed high CT‐loading efficiency (16.58% ± 0.17%). The photodegradation rate of CT@HMS@CH/TA under UV irradiation (48 h) was only 15.31%, indicating a 3.34‐fold UV stability improvement. CT@HMS@CH/TA exhibited a higher CT release rate in response to acidic pH and the presence of chitinase, simulating the prevailing conditions as Magnaporthe oryzae infection. Furthermore, CT@HMS@CH/TA exhibited better adhesion without affecting normal rice growth, significantly upregulating chitinase gene expression and enhancing chitinase activity on M. oryzae, thus enhancing CT antifungal activity.
CONCLUSION
CT@HMS@CH/TA improved CT stability and showed intelligent, controlled release‐performance and higher antifungal efficacy, thus providing a new strategy for efficient application of essential oils for green control of rice blast disease. © 2024 Society of Chemical Industry.
... They also worked on epoxides and hydroperoxides derived by oxidation both photochemically and thermally from naturally monoterpene geranyl acetate. Recently, Rahman et al. [130] reported the effect of ultraviolet-C (UV-C) irradiation on antifungal properties of orange EO against P. digitatum in inoculated Navel oranges, finding that UV-C irradiation of orange EO under atmospheric conditions resulted in a 20% loss of the major constituent limonene, resulting in the generation of three ROS derivatives namely (2S,4 R)-p-mentha-6,8-diene 2-hydroperoxide, (1S,4 R)-p-mentha-2,8-diene-1-hydroperoxide and (1 R,4 R)-p-mentha-2,8-diene-1-hydroperoxide. P. digitatum growth in oranges was significantly inhibited by dipping them in UV-C treated orange EO formulations at concentrations of 1000 -4000 μL L −1 . ...
... No evidence of phytotoxic injury to the fruit was observed. [130] ...
Limiting postharvest losses of fruit from fungal attack is a major priority. While synthetic chemical fungicides are efficacious, the development of chemical resistance and consumer concerns are driving reinvestigation of natural antimicrobial agents. This review emphasizes the control of postharvest decay in citrus fruits with the use of some most common essential oils (EO), the efficacy of EOs in combating fungal infection in both in vitro and in vivo models, and the mode of action of EOs along with the potency of photochemical by-products that have also been investigated as antifungal agents.
... We attribute this reduction to the solubilization of free sugar and its removal during the filtration process. The spectra of both control samples demonstrated the existence of citral, a monoterpene in essential oils, at 200.34, 165.16, and 132.18 ppm [40]. The peaks attributed to citral were reduced in the oxidized orange peel indicating a successful degradation or modification of this component. ...
Orange peels are an abundant food waste stream that can be converted into useful products, such as polyhydroxyalkanoates (PHAs). Limonene, however, is a key barrier to building a successful biopolymer synthesis from orange peels as it inhibits microbial growth. We designed a one-pot oxidation system that releases the sugars from orange peels while eliminating limonene through superoxide (O2• −) generated from potassium superoxide (KO2). The optimum conditions were found to be treatment with 0.05 M KO2 for 1 h, where 55% of the sugars present in orange peels were released and recovered. The orange peel sugars were then used, directly, as a carbon source for polyhydroxybutyrate (PHB) production by engineered Escherichia coli. Cell growth was improved in the presence of the orange peel liquor with 3 w/v% exhibiting 90–100% cell viability. The bacterial production of PHB using orange peel liquor led to 1.7–3.0 g/L cell dry weight and 136–393 mg (8–13 w/w%) ultra-high molecular weight PHB content (Mw of ~1900 kDa) during a 24 to 96 h fermentation period. The comprehensive thermal characterization of the isolated PHBs revealed polymeric properties similar to PHBs resulting from pure glucose or fructose. Our one-pot oxidation process for liberating sugars and eliminating inhibitory compounds is an efficient and easy method to release sugars from orange peels and eliminate limonene, or residual limonene post limonene extraction, and shows great promise for extracting sugars from other complex biomass materials.
... In previous studies, a large number of antimicrobial substances have been reported in citrus, such as flavonoids, essential oils, phenolic acids, and limonoids [25,40,41]. Among them, PMFs, a kind of flavonoid, widely exist in the citrus waste peel and have been regarded as a promising natural antimicrobial active substance in the food industry [42,43]. ...
A major citrus postharvest pathogen, Penicillium italicum (P. italicum), causes substantial economic losses in citrus. In this study, a citral nanoemulsion containing polymethoxylated flavonoids (PMFs), the antimicrobial compounds from citrus, was prepared. The antifungal activity and potential antifungal mechanisms of the nanoemulsion against P. italicum were evaluated. The results showed that the growth of P. italicum was effectively inhibited by the nanoemulsion, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 62.5 and 250 mg L−1, respectively. The nanoemulsion significantly inhibited spore germination and mycelial growth, and it altered the morphology of P. italicum. In addition, the permeability of the cell membrane increased with increasing nanoemulsion concentrations, as evidenced by a rapid rise in extracellular electric conductivity and stronger red fluorescence from mycelia (propidium iodide staining). Compared with the control, the nanoemulsion treatment induced a decrease in total lipid and ergosterol contents in P. italicum cells by 64.61% and 60.58%, respectively, demonstrating that membrane integrity had been disrupted. The results indicated that the PMFs-loaded nanoemulsion exerted antifungal activity against P. italicum by disrupting cell membrane integrity and permeability; such a nanoemulsion may be used as a potential fungicide substitute for preservation in citrus fruits.
... The products of medicinal plants like EOs and their antimicrobial properties have been empirically recognized for centuries, but recently the antimicrobial properties have been studied and confirmed scientifically [13][14][15]. These EOs effectively control the growth of different microorganisms like fungus, yeasts, bacteria, etc., which has been reported in several studies [16][17][18][19][20][21]. The bark extract of hog plums exhibits a valuable antibacterial activity, while the aqueous extract of the bark has shown a moderate antibacterial activity against Escherichia coli, Salmonella typhimurium, and Vibrio cholerae [22,23]. ...
The hydro-distilled essential oil of hog plum peel may be used for enhancing the flavor
and taste of food products as well as for hiding the unpleasant odor of drugs. Thus, the waste peels of Spondias mombin appear to have economic importance. To find out the chemical composition and anti-microbial properties of hog plum peel oil, the samples were collected from different regions of Bangladesh for extraction and identification of volatile compounds by GC-MS, where dichloromethane was used as an extraction solvent. The required standard analytical methods were used to assay the anti-microbial properties of hog plums. In this study, pentenyl-3-thy-met-4-alphamethyl-
alpha-ethanol-oxiranen (29.04%), (3,3.1,1)-4-dimethylethyl-1,1-phenol (8.00%), cycohexanol-3 (10.85%), 4-hydroxy-penzeneethanamine (7.09%), hydroxylamine (4.63%), dibutyl phthalate (6.85%), etc., were majorly determined. Consequently, the highest content of 75.81% volatile compounds was found in the Dinajpur district, where the lowest content of 35.00% was found in the Rajshahi district. In contrast, 33 volatile compounds were identified in hog plum peels collected from the Barishal district, whereas 22 compounds were detected in the peel samples collected from the Dinajpur district. In addition, the antimicrobial activity of the oil was analyzed by the disk diffusion method, and the results revealed that the highest Ciprocin content was recorded in the hog plums of Barishal (22.0–23.0 mm), while the lowest was recorded in the Mymensingh sample (20.67–21.63 mm), which was on par with Rajshahi sample (20.70–21.50 mm). The results of the anti-fungal activities of the peel oil showed the highest zone of inhibition against the Aspergillus niger (11.63 � 0.0003 mm) and Penicillium oxalicum (13.67 � 1.97 mm) content of the Rajshahi and Pabna district samples, respectively.
... The products of medicinal plants like EOs and their antimicrobial properties have been empirically recognized for centuries, but recently the antimicrobial properties have been studied and confirmed scientifically [13][14][15]. These EOs effectively control the growth of different microorganisms like fungus, yeasts, bacteria, etc., which has been reported in several studies [16][17][18][19][20][21]. The bark extract of hog plums exhibits a valuable antibacterial activity, while the aqueous extract of the bark has shown a moderate antibacterial activity against Escherichia coli, Salmonella typhimurium, and Vibrio cholerae [22,23]. ...
Citation: Plabon, M.E.A.; Mondal, S.C.; Or Rashid, M.M.; Chowdhury, M.K.; Saeid, A.; Althobaiti, F.; Dessok, E.S.; Rehmani, M.I.A.; Mustafa, S.K.; Islam, M.S. Chemical Composition and Anti-Microbial Activity of Hog Plum (Spondias mombin L.) Peel Oil Extracted from Different Regions of Tropical Climates. Horticulturae 2021, 7, 428. https://doi.org/10.3390/ horticulturae7110428 Academic Editors: Dasha Mihaylova and Aneta Popova
