Mandarin Oil Research Articles

Konjac glucomannan films incorporated pectin-stabilized Mandarin oil emulsions: Structure, properties, and application in fruit preservation

To enhance the water-resistance and antibacterial properties of KGM films, mandarin oil (MO), was directly emulsified by pectin and then dispersed to the KGM matrix. The effect of MO concentration (0, 0.5, 1.0, 1.5, and 2 wt%) on the performance of the film-forming emulsions as well as the emulsion films was investigated. The results revealed that pectin could encapsulate and protect MO, and KGM as film matrix could further contributed to the high stability of the film-forming emulsions. The FT-IR, XRD, and SEM suggested that MO stabilized by pectin was uniformly distributed in the KGM matrix. The compatibility and good interaction between KGM and pectin contributed to highly dense and compact structure. Furthermore, increasing the concentration of MO effectively improved water-resistance, oxygen barrier, and antimicrobial activity of the KGM based films. The 1.5 wt% MO loaded KGM film had the highest tensile strength (72.22 MPa) and water contact angle (θ = 95.73°), reduced the WVP and oxygen permeability by about 25.8 % and 32.8 times, respectively, prolonged the shelf life of strawberries for 8 days. As demonstrated, the 1.5 wt% MO-loaded KGM film has considerable potential for high-performance natural biodegradable active films to ensure food safety and reduce environmental impacts.

Efficacy of Nano-Encapsulated Mandarin Oil using (Polyethylene Oxide/Polyacrylamide) and Gamma Irradiation against Culex pipiens Larvae

Efficacy of Nano-Encapsulated Mandarin Oil using (Polyethylene Oxide/Polyacrylamide) and Gamma Irradiation against Culex pipiens Larvae

Effect of edible coating incorporating sodium carboxymethyl cellulose/cellulose nanofibers and self-produced mandarin oil on strawberries

Edible coatings were prepared using a mixture of 1.0 % (w/v) sodium carboxymethyl cellulose (CMC), 0.5 % (w/v) cellulose nanofibers (CNF), and varying concentrations of mandarin oil (MO) at 0.05, 0.1, 0.2, 0.3, or 0.4 % (w/v). The research investigated the physicochemical characteristics and antifungal activities of the films on Botrytis cinerea (B. cinerea). CMC/CNF/MO coatings were used to preserve the strawberries (Amaou). The changes in quality and antifungal activity on the strawberries were assessed during storage at 5 °C and 85 ± 5 % relative humidity (RH). Results showed the major components of MO include β-pinene, limonene, and methyl palmitate. The addition of MO into coatings indicated a significant effect on the properties of coating solutions as well as the film characteristics as shown in b* and roughness values increased strongly. The coatings contained MO also represented a marked effect on fruit weight loss and antifungal activity against B. cinerea strain both in vitro and in vivo. The addition of MO at a concentration of 0.05 % illustrated the significant effect in controlling weight loss and antifungal activity on strawberries.

Potential of selected plant essential oils in management of Sitophilus oryzae (L.) and Rhiyzopertha dominica (F.) on wheat grains

BackgroundTwo plant essential oils, basil (Ocimum basilicum L.) and petitgrain mandarin (Citrus reticulate L.), and one pyrethroid chemical insecticide, lambda-cyhalothrin, were evaluated against two of the most important stored product insect pests, Sitophilus oryzae and Rhyzopertha dominica, on wheat grains under laboratory conditions using mixing with feeding method. The effect of the tested materials was studied on F1 progeny of the tested insects. Chemical components of the oils and side effects on protein content percentage, total carbohydrates of wheat grain and germination were investigated.ResultsResults obtained showed that the two oils had a good insecticidal effect on the tested insects. Petitgrain mandarin oil was the premier. The two tested essential oils reduced the F1 progeny. In addition, the progressive of periods after storage (0–180 days) significantly reduced protein content (%) and total carbohydrates compared to control. Nearly, there were no significant differences between treatments (LC50 and LC95) of basil and (petitgrain) mandarin on the studied parameters. Germination percentages from 0 to 180 days post-storage had slight differences between control and treatments for oils. Lambda-cyhalothrin significantly reduced germination, especially with the LC95 from 60 to 180 days. Chemical analysis demonstrated that the main components of basil oil were linalool, eugenol, methyl chavicol and cani, while the main components of petitgrain mandarin oil were dimethyl panthenalate, α-terpinene, β-cinem and citral accounting for 71.1 and 95% of the two oils, respectively.ConclusionsThe results obtained proved that the two tested plant essential oils had an obvious role in suppressing the activity of the two tested insects and can be used in an integrated pest management program. The two tested essential oils can be used as green pesticides and can be effective alternatives for chemical pesticides.

GC/MS analysis and potential synergistic effect of mandarin and marjoram oils on Helicobacter pylori

Helicobacter pylori can cause chronic gastritis, peptic ulcer, and gastric carcinoma. This study compares chemical composition and anti-H. pylori activity of mandarin leaves and marjoram herb essential oils, and their combined oil. GC/MS analysis of mandarin oil revealed six compounds (100% identified), mainly methyl-N-methyl anthranilate (89.93%), and 13 compounds (93.52% identified) of marjoram oil, mainly trans-sabinene hydrate (36.11%), terpinen-4-ol (17.97%), linalyl acetate (9.18%), and caryophyllene oxide (8.25%)). Marjoram oil (MIC = 11.40 µg/mL) demonstrated higher activity than mandarin oil (MIC = 31.25 µg/mL). The combined oil showed a synergistic effect at MIC of 1.95 µg/mL (same as clarithromycin). In-silico molecular docking on H. pylori urease, CagA, pharmacokinetic and toxicity studies were performed on major compounds from both oils. The best scores were for caryophyllene oxide then linalyl acetate and methyl-N-methyl anthranilate. Compounds revealed high safety and desirable properties. The combined oil can be an excellent candidate to manage H. pylori.

Response surface methodology for optimization studies of hydro-distillation of essential oil from pixie mandarin (Citrus reticulata Blanco) peels

Abstract Essential oil extraction technique from mandarin pixie peels by hydro-distillation is optimized by response surface methodology (RSM). Mathematical techniques were used in experimental design to evaluate the impacts of factors that affect the extraction process and improve the yield of the extraction process. A central mixed design based on influencing variables such as water ratio (3–5 mL/g), temperature (110–130 °C) and extraction time (90–150 min) was adopted with essential oil yield as the target function. Correlation analysis of the mathematical regression model showed that the quadratic polynomial model can be used to optimize hydro-distillation of pixie mandarin oil. The results showed that under the optimum extraction conditions, the highest quantity of essential oils was achieved (7.28 mL/100 g materials). In terms of statistical analysis, the significance levels (p-value <0.05) of the model showed that the experimental results had a good impact between factors. The coefficient of determination indicating the match between the experimental value and the predicted value of the model was high (R2>0.9). The chemical composition of the essential oil was analyzed by Gas Chromatography-Mass Spectrometry, revealing the dominance of limonene content (97.667%), which implies that the essential oil of pixie mandarin could be an alternative source of limonene.

Bioactive Molecules of Mandarin Seed Oils Diminish Mycotoxin and the Existence of Fungi.

Mandarin is a favorite fruit of the citrus family. Mandarin seeds are considered a source of nontraditional oil obtained from byproduct materials. This investigation aimed to assess the biomolecules of mandarin seeds and evaluated their antimycotic and antimycotoxigenic impact on fungi. Moreover, it evaluated the protective role of mandarin oil against aflatoxin toxicity in cell lines. The two types of extracted oil (fixed and volatile) were ecofriendly. The fatty acid composition, tocopherol, sterols, and carotenoids were determined in the fixed oil, whereas volatiles and phenolics were estimated in the essential oil. A mixture of the two oils was prepared and evaluated for its antimicrobial impact. The reduction effect of this mixture was also investigated to reduce mycotoxin secretion using a simulated experiment. The protective effect of the oil was evaluated using healthy strains of cell lines. Fixed oil was distinguished by the omega fatty acid content (76.24%), lutein was the major carotenoid (504.3 mg/100 g) and it had a high β-sitosterol content (294.6 mg/100 g). Essential oil contained limonene (66.05%), α-pinene (6.82%), β-pinene (4.32%), and γ-terpinene (12.31%) in significant amounts, while gallic acid and catechol were recorded as the dominant phenolics. Evaluation of the oil mix for antimicrobial potency reflected a considerable impact against pathogenic bacteria and toxigenic fungi. By its application to the fungal media, this oil mix possessed a capacity for reducing mycotoxin secretion. The oil mix was also shown to have a low cytotoxic effect against healthy strains of cell lines and had potency in reducing the mortality impact of aflatoxin B1 applied to cell lines. These results recommend further study to involve this oil in food safety applications.

Safety and efficacy of a feed additive consisting of expressed mandarin oil from the fruit peels of Citrus reticulata Blanco for use in all animal species (FEFANA asbl).

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of expressed mandarin oil from the fruit peels of Citrus reticulata Blanco, when used as a sensory additive (flavouring) in feed and water for drinking for all animal species. The FEEDAP Panel concluded that the essential oil under assessment is safe up to the maximum proposed use levels in complete feed of 15 mg/kg for poultry, 33 mg/kg for pigs, 30 mg/kg for ruminants, 40 mg/kg for horse, and 15 mg/kg for salmon and rabbit. The presence of perillaldehyde was identified as a source of potential concern. However, in target species fed citrus by‐products as part of daily feed the use of the expressed mandarin oil in feed was not expected to increase the exposure to perillaldehyde to a relevant extent (< 4%). For companion animals and ornamental fish not normally exposed to citrus by‐products, no conclusion can be drawn. The FEEDAP Panel considered that the use in water for drinking is safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed. No concerns for consumer safety were identified following the use of the additive up to the maximum proposed use level in feed. The essential oil under assessment should be considered as irritant to skin, eyes and the respiratory tract, and as a skin sensitiser. The use of the additive in animal feed under the proposed conditions of use was not expected to pose a risk for the environment. Expressed mandarin oil was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Synergistic mechanism of insecticidal activity in basil and mandarin essential oils against the tobacco cutworm

Owing to the complexity in the chemical composition of plant essential oils, they often display enhanced insecticidal activity when applied as a mixture. Although the insecticidal activity of plant essential oils has been gaining more attention recently, understanding in the mechanism of synergy has not been studied as much. In the present study, insecticidal activity of 28 individual essential oils and their mixtures against the third instar larvae of Spodoptera litura was examined. Among the oils tested, basil oil exhibited the strongest contact toxicity, and mandarin oil displayed the greatest boosting effect when the remaining oils were mixed with basil oil. Estragole and linalool were determined as the major active constituents for the insecticidal activity of basil oil and limonene for mandarin oil from the chemical analyses and compound elimination assay. Based on the LD50 values, the binary mixture of basil and mandarin oils exhibited enhanced toxicity compared to the individual application of the two oils, showing synergy ratios of 1.3 and 1.4 from two statistical models. As for the major active compounds, synergistic interaction was found in tertiary mixture of estragole, linalool, and limonene in the blending ratio of 7:2:7, displaying the same insecticidal activity of the binary mixture of basil and mandarin oils. The synergistic effect was only observed in the tertiary mixture, indicating each compound play crucial roles of the overall contact toxicity. Increased penetration through cuticular layer and amplified neurophysiological response were proposed for the mechanism of synergistic effect.

STUDIES ON MICROBIOLOGICAL AND CHEMICAL PROPERTIES OF PROBIOTIC CONTAINING LABNEH

Labneh is one of the most widespread dairy products in the Middle East. It is known as concentrated youghurt. Its manufacturing and consumption in Egypt has been increased recently because of its nutritional and health benefits. The objective of this study was to improve the nutritional and health attributes of Labneh. Therefore the effects of incorporating probiotic bacteria and mandarin oil on the quality of Labneh have been studied. The obtained results indicated that using probiotic bacteria affect the chemical, rheological and organoleptic properties of Labneh. Although all Labneh treatment were accepted by panelists, treatment (T3) that was made by adding L.plantarum was the most acceptable Labneh treatment. Adding mandarin oil in the second part of this study indicated that adding mandarin oil caused a slight increase of total solids and fat contents, while decreased acidity, acetaldehyde and diacetyl contents and acidity of Labneh treatments and decreased the values of some texture parameters. Increasing mandarin oil a bove 0.2% decreased the scores of organoleptic properties. Treatments T1 and T2 these made by adding 0.1 and 0.2% mandarin oil were the most acceptable Labneh treatments. Therefore it is possible to make a good quality Labneh using L.plantarum and adding up to 0.2 % mandarin oil.

RESTRAIN HYPERCHOLESTEROLEMIA WITH ORANGE AND MANDARIN VOLATILE AND FOLDED OILS

ABSTRACT The findings of this study proved that orange peels contain more twice oil yield over mandarin peels (0.24% and 0.12%, respectively). Concentrated orange and mandarin peel essential oils were obtained by fractional distillation. The chemical constituents of original orange and mandarin oils (OO and MO) and their fivefold (5FOO and 5FMO) were fractionated and identified by GC/MS and GC. Limonene was the major monoterpene component in orange and mandarin oils, 89.65% and 65.57%, respectively, followed by myrcene (3.95%) and γ-terpinene (23.07%) in orange and mandarin oils, respectively. Octanal (1.47%) and linalool (1.5%) were the abundant oxygenated components in orange and mandarin oils, respectively. The decrement percentages of limonene were 18.58 and19.25% in five fold orange and mandarin oils, respectively. The major oxygenated component in 5FOO was the alcoholic β- Cis-terpeneol (4.27%). The main esters of mandarin oil, methyl N-methyl anthranilate and geranyl acetate were increased to 0.45% and 1.05%, respectively in 5FMO. In general, total oxygenated compounds percentages increased by 6.9 and7.3 times after folding of orange and mandarin oils, respectively. The above mentioned oils, pure limonene and synthetic antioxidant (BHT) were orally administrated for hypercholesterolemic rats for four weeks. No significant differences were recorded among groups of rats administrated with all different tested oils in body weight gain (%) or feed intake (g) (p≤ 0.05). In general, all rat groups administrated with orange and mandarin oils and their concentrates, showed improvement in HDL levels nearly to normal level compared to the negative control. Thus, the decrement of serum cholesterol level among cholesterol-fed groups did not correlate with the amount of limonene consumed by rats and may be related to other minor components associated with limonene and shared in the antioxidant effect. The efficiency of folded oils on hypocholesterolemic rats did not affect by decreasing limonene by deterpenation process.

Effect of Some Citrus Essential Oils on Post-Harvest Shelf Life and Physicochemical Quality of Strawberries during Cold Storage

Utilization of essential oils alone or incorporation with edible films is an appropriate technique to conserve the quality attributes and reduce post-harvest deterioration in fresh vegetables and fruits. Strawberries, being perishable fruits have a short shelf life, and using essential oils is considered one of the most suitable methods to prolong their shelf life during storage. The current study assessed the impact of different essential oils, including lemon oil (L), orange oil (O) and mandarin oil (M) on the physicochemical and microbial load of strawberries (Fragaria × ananassa cv. Festival) stored at 2 ± 1 °C and 95% relative humidity (RH) for 18 days. The differences in the physicochemical and microbial properties of strawberries were assessed by determining the following parameter changes: weight loss, decay percentage, firmness, soluble solids content, titratable acidity, color, anthocyanins, vitamin C, total phenol, total antioxidant, catalase activity, polyphenol oxidase activity, sensory evaluation, microbial content, total coliforms, molds, and yeasts. The results of this study indicated that the fruits treated with all essential oils treatments (L, O and M) had higher total antioxidant content and physicochemical properties than untreated fruits, due to protection against the microbial growth of molds, and yeasts. At the end of the storage period, the treated fruits showed a greater acceptance and sensory attributes than the untreated fruits. Furthermore, the correlation study showed a significant and negative relationship between the total antioxidant of treated fruits and following quality attributes including, weight loss, decay percentage, respiration rate soluble solids content, polyphenol oxidase activity, molds, and yeasts. It is noteworthy that all the essential oil treatments extended the shelf-life of strawberries and delayed their deterioration up to 18 days.

Influence of Sumac Extract on the Physico-chemical Properties and Oxidative Stability of Some Cold Pressed Citrus Seed Oils.

The acidity values changed between 1.03 mgKOH/100g (control) and 1.11 mgKOH/100g (0.1% extract) for orange oil, 1.06 mgKOH/100g (0.5% extract) and 1.13 mgKOH/100g (0.1% extract) and 1.25 mgKOH/100g (0.5% extract) and 1.31 mgKOH/100g (control) for mandarin oil. The peroxide values were determined between1.37 meqO2/kg (0.5% extract) and 1.43 meqO2/kg (0.1% extract) for orange oil, between 1.24 meqO2/kg (control) and 1.27 meqO2/kg (0.1% extract) for lemon and 1.60 meqO2/kg (0.5% extract) and 1.71 meqO2/kg (control) in mandarin oil samples. The viscosity values of samples changed between 0.051 Pa.S (control) and 0.065 Pa.S (0.5% extract) for orange, 0.051 Pa.S (control) and 0.067 Pa.S (0.5% extract) lemon and 0.044 Pa.S (control) and 0.057 Pa.S (0.5% extract) in mandarin oil samples. At the end of storage study (28th day), the acidity values significantly changed, and their values ranged between 2.28 mgKOH/100g (0.5% extract) and 3.64 mgKOH/100g (control) in orange, 1.67 mgKOH/100g (0.5% extract) and 2.28 mgKOH/100g (control) in lemon and 1.74 mgKOH/100g (0.5% extract) and 2.36 mgKOH/100g (control) in mandarin oil samples. While peroxide values vary between 11.68 meqO2/kg (0.5% extract) and 32.57 meqO2/kg (control) for orange, 12.55 meqO2/kg (0.5% extract) and 34.63 meqO2/kg (control) for lemon and between 17.56 meqO2/kg (0.5% extract) and 37.81 meqO2/kg (control) for mandarin oils, viscosity values after 28 day storage changed between 0.123 Pa.S (0.5% extract) and 0.675 Pa.S (control) in orange, 0.257 Pa.S (0.5% extract) and 0.697 Pa.S (control) in lemon and 0.215 Pa.S (0.5% extract) and 0.728 Pa.S (control) in mandarin oil samples.

Composite hydrogels with application in wound healing

More and more worrying cases of patients with wound infections caused by resistance to antibiotic drug treatment in many bacterial strains have led to advanced research to solve this common problem, which may even cause death. Mixing a hydrogel with some antimicrobial agents leads to a composite dressing that includes the characteristics required for successful healing, reassuring the properties of each material used, and thus ensuring the action of all at one place, compared to their action [1]. The present work is centralized on wound healing using a polyvinyl alcohol and alginate hydrogel that includes silver nanoparticles and antimicrobial mandarin oil. Thus, the focus is based on the release of antimicrobial agents at the site of the wound and on maintaining a wet environment for faster and more healing to absorb a significant amount of exudate and, last but not least, to present biocompatibility [2]. The paper presents the methods of analysis applied on the obtained hydrogels for wound treatment, using physical-chemical analyzes such as FT-IR, XRD, SEM, TEM and biological test based on the evaluation of the antibacterial activity of the composite hydrogels and on their biocompatibility assessment, which showed suitable results of dressing in wound dressing applications.

The stability of three different citrus oil-in-water emulsions fabricated by spontaneous emulsification

In this study, emulsions were prepared through spontaneous emulsification, using three different citrus oils as the oil phase and Tween 80 as the surfactant. Utilizing 4% Tween 80, three types of citrus oil emulsions were prepared with small particle size, monomodal distribution and high transmission. After 24 h, each emulsion exhibited different degrees of gravitational separation. Mandarin oil emulsions were the most unstable, showing coalescence of small droplets with an obvious cream layer formed at 9 h. Bergamot oil emulsions possessed small droplets with the best stability over 24 h, due to their relatively polar components (e.g. linalyl acetate) and water-insoluble constituents (e.g. γ-terpinene). These results suggest that the emulsifying properties and instability mechanism of citrus oil emulsions are strongly dependent on the inherent properties and composition of citrus oils. This study is significant for the development of an effective strategy to improve the stability of citrus oil-based colloidal systems.

Enzymatic Process Enhances the Flavour Profile and Increases the Proportion of Esters in Citrus Essential Oils.

Citrus essential oils (CEOs) are important flavors in the food and confectionary industries. A lipase process was proposed for enhancing the flavor profiles and increasing the proportions of esters in CEOs. The effects of the enzymatic process were explored by detecting the constituents of the CEOs of American sweet orange oil (ASO) and Brazil mandarin oil (BMO) through GC/MS and sensory evaluation by a trained panel, and positive effects were confirmed by both methods. A further eleven kinds of CEOs were treated via the lipase process and increments of 10-1170% were achieved in the proportions of esters, which were mostly ethyl esters. Enhancement in fruity odor, especially the top note, was demonstrated by all CEOs after enzymatic processing. All CEOs were tested for antimicrobial activities, and only ASO displayed fairly ideal antimicrobial activities. Meanwhile, modified ASO showed a certain increase in antimicrobial activities. This methodology might be considered a sustainable route for acquiring 'natural' essential oils with enhanced flavor profiles and simultaneously enhancing the comprehensive utilization of citrus fruits.

Antimicrobial and Antiradical Potential of Four Agro-waste Citrus Peels Cultivars

The peels essential oil profiles of four new cultivars of Citrus species have been studied by GC-MS. The hydro-distilled oils yield was 0.1 - 1.0% (w/w) with the highest yield in lime peel. Out of the forty-one characterized components, limonene was the major monoterpene hydrocarbons detected in all tested samples (89.3 ± 0.0, 88.5 ± 0.2, 78.1 ± 0.3 and 53.0 ± 0.0% in grapefruit, orange, mandarin and lime oils, respectively). Both β-pinene (16.0 ± 0.5%) and p-cymene (13.9 ± 0.2%) were major in lime oil, while mandarin oil was rich with γ-terpinene (9.0 ± 0.5%). Concentration of volatile oils constituents was calculated based on the average of 3 determination ± standard deviation (S.D.). Three citrus oils; orange (100 μl/ml), lime and grapefruit (250 μl/ml), demonstrate relatively equivalent antiradical potential (inhibit 70% of DPPH) as vitamin E (5.2 μl/ml), having IC50 of 110 ± 10.0, 142 ± 2.5 and 155 ± 5.0 μl/ml, respectively. Lime peel essential oil showed the highest antimicrobial activity recording MIC90 of 14, 11, 12 and 9 μl/ml against Staphylococcus aureus, E. coli, Candida albicans and Aspergillus flavus, respectively, while other tested oils demonstrated moderate antimicrobial activity against the eight pathogenic microorganisms.

Analysis of Solvent Properties of Mandarin Oil

Mandarin oil distilled from orange peels of producing the four different regions in China was the compound for the major component 85% limonene, mandarin oil were extracted twice to ensure the purity of limonene, respectively. The spectrum test and Solvent solubility of chemical analysis indicate that it is a certain fluorescence effect and the ultraviolet absorption scope of peak is at 220~280nm, the capability to dissolve polyphenyl foam plastics replace benzene, methylbenzene and tetrachloroethylene by Mandarin oil, the results show that limonene is a safe, non-toxic organic solvent with high performance in chemical industry.

Evaluación in vitro de la actividad fungistática del aceite esencial de mandarina sobre el crecimiento de Penicillium sp.

Los hongos Penicillium digitatum y P. italicum representan mundialmente la principal pérdida conómica para el sector citrícola durante la etapa de poscosecha. El uso de fungicidas es cada vez más restringido debido a sus efectos carcinogénicos, teratogénicos, alta residualidad, período largo de degradación, contaminación ambiental y aumento de la resistencia por parte de los patógenos, entre otros. Los compuestos antimicrobianos de origen natural pueden ser una alternativa viable y segura para minimizar las pérdidas por enfermedades que enfrenta el sector. En este trabajo se evaluó y comparó in vitro la actividad antifúngica del aceite comercial de mandarina, timol y carvacrol, a concentraciones de 40 y 50 ppm, usando el método de difusión en agar y pruebas microbiológicas. Todos los compuestos y aceites evaluados presentaron un porcentaje de inhibición entre 50% y 100%, para ambos hongos, siendo mayor la inhibición en dosis de 50 ppm. Carvacrol presentó mayor actividad antifúngica sobre ambos hongos. P. digitatum mostró mayor sensibilidad que P. italicum al efecto de los aceites esenciales evaluados. El aceite esencial comercial de mandarina puede ser una alternativa para el control de enfermedades poscosecha causadas por Penicillium sp., en productos vegetales.

INSECTICIDAL AND REPLLENET ACTIVITIES OF CITRUS PEEL OILS AGAINST MEALYBUG ICERYA SEYCHELLARUM (WESTWOD)

essential oils extracted from peels of five citrus fruit species namely: navel and baladi oranges (Citrus sinensis L.), grapefruit (Citrus paradisi Macfad), lemon (Citrus limon L.) and mandarin (Citrus reticulata Blanco), belonging to family Rutaceae were tested for their insecticidal and repellent activities at three different concentrations (1000, 5000, 10000ppm) against nymphs and adults of mealybug Icerya seychellarum . Also, formulated compounds, navel orange oil (1%), limonene (1%) and two recommended reference products (2% insecticidal soap and 1.5% Super Misrona), were bioassayed against mealybug I. seychellarum. The results revealed that, the oil of navel orange achieved the highest toxicity against nymphs and adults of mealybug I. seychellarum with LC50 values of (406.97, 370.04 ppm), respectively, while, oil of mandarin recorded the lowest toxicity (LC50= 4148.80, 3435.99 ppm), respectively. Navel orange oil (1%) was more potent than limonene (1%) alone, while, limonene (1%) was more potent than the two reference products. Citrus species oils exhibited high repellency rate against the nymphs of I. seychellarum at the used concentrations. The highest repellency was achieved by navel orange oil, while, the lowest one was recorded with mandarin oil. The essential oils of five citrus species were isolated by hydrodistillation and the analysis of essential oil by GC/MS revealed the presence of 32 peaks, approximately all peaks were identified. The chemical composition showed that limonene was the main constituent in the five citrus oils and ranged from 67.50 to 91.20%. No phytotoxic symptoms were observed on Mango leaves treated by the citrus essential oils (Orange and baladi) and limonene. The results of the present study suggested that, orange oils (Navel and baladi) and pure limonene used as safe, potential natural products for control of I. seychellarum on Mango trees and may be used as alternatives to the reference products after application of these results in the semifield and field experiments.