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Essential oils (EOs), which are complex biomolecules composed of volatile compounds, have emerged as a new strategy to deal with bacterial infections and as a valid alternative to synthetic drugs. Here, we report the modification of biodegradable wet-spun microfibers composed of cellulose acetate (CA) and polycaprolactone (PCL) with EOs, aiming at their localized, controlled release. Cinnamon leaf oil (CLO), cajeput oil (CJO), and clove oil (CO) were selected from a group of 20 EOs according to their minimal inhibitory concentration (MIC) against Staphylococcus aureus (

Pseudomonas aeruginosa is considered a public threat, with antibiotics increasing their resistance. Essential oils (EOs) have demonstrated significant effects against microorganisms. However, due to their volatile nature, they cannot be used in their free-state. Here, hydrogel-like films were produced from a combination of sodium alginate (SA) and gelatin (GN) to serve as delivery platforms for the controlled release of cinnamon leaf oil (CLO) entrapped within chitosan (CS) microcapsules. The minimum inhibitory concentration (MIC) of CLO was established at 39.3 mg/mL against P. aeruginosa. CS microcapsules were prepared via ionotropic gelation with tripolyphosphate (TPP), encapsulating CLO at MIC. Successful production was confirmed by fluorescent microscopy using Nile red as a detection agent. Microcapsules were embedded within a biodegradable SA/GN polymeric matrix processed by solvent casting/phase inversion with SA/GN used at 70/30 polymer ratio at 2 wt.% SA concentration. A concentration of 2 wt.% CaCl2 was used as a coagulation bath. The CLO-containing CS microcapsules’ homogeneous distribution was guaranteed by successive vortex and blending processes applied prior to casting. CLO controlled release from the films was monitored in physiological pH for 24 h. Hydrated films were obtained, with the presence of loaded CS capsules being confirmed by FTIR. Qualitative/quantitative antimicrobial examinations validated the loaded film potential to fight P. aeruginosa., Authors acknowledge the Portuguese Foundation for Science and Technology

This study was performed to examine the inhibitory effect of combined treatments with a positively charged cinnamon leaf oil (P-CL) emulsion and various organic acids against Listeria monocytogenes inoculated on fresh-cut Treviso leaves. Combined treatments with a P-CL emulsion and an organic acid exhibited a higher inhibitory effect than treatment with each alone or NaOCl. The highest inhibitory effect was achieved by combined treatment with the P-CL emulsion and lactic acid (LA), which showed a 2.85-log reduction compared to distilled water washing. In addition, the inhibitory effect of the combined treatment was maintained during 6 days of subsequent storage, and showed a 3.24-3.39-log reduction compared to unwashed samples. Treviso leaves treated with the P-CL emulsion and LA also maintained their sensorial properties, including appearance, odor, hardness, freshness, and overall acceptability, during subsequent storage. Therefore, combined treatment with a P-CL emulsion and LA can be used to effectively ensure the microbial safety and organoleptic quality of fresh-cut Treviso leaves.

Most insects utilize a diverse array of olfactory cues for host finding and reproduction behaviors. Males of several Dacini fruit fly species (Tephritidae) are selectively attracted to certain phytochemicals to acquire sex pheromone precursors. Despite the importance of olfaction, only a limited number of olfactory receptors (ORs) in Dacini fruit flies have been characterized. In this study, I focused on the OR94b-2 subfamily, because a clade consisting of these homologs was distinctly localized from other OR clades in a constructed phylogenetic tree. To deorphanize the ORs, I used plant essential oils to screen ligands. Using heterologous expression in Xenopus oocytes, I analyzed the functional properties of BdorOR94b-2 and ZcucOR94b-2 from the Oriental fruit fly, Bactrocera dorsalis, and the melon fruit fly, Zeugodacus cucurbitae, respectively. I found that cinnamon leaf oil evoked responses in oocytes expressing BdorOR94b-2 and the corresponding co-receptor BdorORCO. Gas chromatography-mass spectrometry analysis indicated that eugenol is a major component of cinnamon leaf oil. In accordance with the response to cinnamon leaf oil containing eugenol, BdorOR94b-2/BdorORCO revealed a weak but significant response to eugenol. BdorOR94b-2/BdorORCO also responded to isoeugenol, but not to other related aromatic semiochemicals such as known male-specific attractants and sex pheromones. In contrast, ZcucOR94b-2/ZcucORCO did not respond to any of the phenolic compounds tested, including eugenol analogs. Therefore, BdorOR94b-2/BdorORCO is narrowly tuned to eugenol analogs, whereas ZcucOR94b-2/ZcucORCO likely binds to other compound(s).

Some plants that are processed into foods often contain natural substances that may be hazardous to human health. One example is coumarin, which is known to cause liver and kidney damage in rats, mice and probably humans. Coumarin is found in different Cinnamomum species such as Cinnamomum cassia, Cinnamomum loureiroi, and Cinnamomum burmannii; all commonly referred to as cassia. Another hazardous substance is Safrole. Safrole is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals; and is mainly present in cinnamon leaf oil and could be a possible contaminant in cinnamon powder. European Council’s Directive on food flavourings 88/388/EEC limits safrole in foodstuffs to 1ppm. The content of coumarin is regulated in the European Regulation (EC) No 1334/2008. In the present study, coumarin and safrole levels were analyzed in locally bought cinnamon samples and cinnamon-flavored food products using a validated HPLC method with diode array detector (DAD). Appreciable amounts of coumarin were found in bakery products with concentrations up to 39.466 mg/kg in certain kinds of cookies, whereas safrole was undetectable. Our exposure data on coumarin in bakery products show that there is still a need for a continued regulation of coumarin in foods. A toxicological re-evaluation of coumarin with the aim to derive scientifically founded maximum limits should be conducted with priority.

New approaches to deal with the growing concern associated with antibiotic-resistant bacteria are emerging daily. Essential oils (EOs) are natural antimicrobial substances with great potential to mitigate this situation. However, their volatile nature, in their liquid-free form, has restricted their generalized application in biomedicine. Here, we propose the use of cellulose acetate (CA)/polycaprolactone (PCL) wet-spun fibers as potential delivery platforms of selected EOs to fight infections caused by Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Twenty EOs were selected and screened for their minimal inhibitory concentration (MIC), using the antibiotic ampicillin as positive control. The cinnamon leaf oil (CLO), cajeput oil (CJO), and the clove oil (CO) were the most effective EOs, against the Gram-positive (MIC &lt, 22.38 mg/mL) and the Gram-negative (MIC &lt, 11.19 mg/mL) bacteria. Uniform microfibers were successfully wet-spun from CA/PCL with an averaged diameter of 53.9 &plusmn, 4.5 &micro, m, and then modified by immersion with CLO, CJO and CO at 2 &times, MIC value. EOs incorporation was confirmed by UV-visible spectroscopy, Fourier-transformed infrared spectroscopy, and thermal gravimetric analysis. However, while microfibers contained ampicillin at MIC (control) after the 72 h modification, the CLO, CO and CJO-loaded fibers registered &asymp, 14%, 66%, and 76% of their MIC value, respectively. Data showed that even at small amounts the EO-modified microfibers were effective against the tested bacteria, both by killing bacteria more quickly or by disrupting more easily their cytoplasmic membrane than ampicillin. Considering the amount immobilized, CLO-modified fibers were deemed the most effective from the EOs group. These results indicate that CA/PCL microfibers loaded with EOs can be easily produced with increased antibacterial action, envisioning their use as scaffolding materials for the treatment of infections.

In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association initiated the safety re-evaluation of over 250 natural flavor complexes (NFCs) used as flavor ingredients. This publication, 4th in a series focusing on the safety evaluation of NFCs, presents an evaluation of NFCs rich in hydroxyallylbenzene and hydroxypropenylbenzene constituents using a procedure initially published in 2005 and updated in 2018 that evaluates the safety of naturally occurring mixtures for their intended use as flavoring ingredients. The procedure requires the characterization of the chemical composition for each NFC and subsequent organization of the constituents into defined congeneric groups. The safety of each NFC is evaluated using the conservative threshold of toxicological concern (TTC) approach together with studies on absorption, metabolism and toxicology of the NFC and its constituent congeneric groups. By the application of this procedure, seven NFCs, derived from clove, cinnamon leaf and West Indian bay leaf were affirmed as “generally recognized as safe (GRAS)” under their conditions of intended use as flavor ingredients. An eighth NFC, an oleoresin of West Indian bay leaf, was affirmed based on its estimated intake, which is below the TTC of 0.15 μg/person per day for compounds with structural alerts for genotoxicity.

In this study, Ecklonia cava alginate (ECA) was used as a base material for biodegradable films. Calcium chloride (CaCl2) was used as a cross-linking agent, and various concentrations (0%, 0.4%, 0.7%, and 1.0%) of cinnamon leaf oil (CLO) or cinnamon bark oil (CBO) were incorporated to prepare active films. The ECA film containing 3% CaCl2 had a tensile strength (TS) of 17.82 MPa and an elongation at break (E) of 10.36%, which were higher than those of the film without CaCl2. As the content of essential oils (EOs) increased, TS decreased and E increased. Addition of CLO or CBO also provided antioxidant and antimicrobial activities to the ECA films. The antioxidant activity of the ECA film with CBO was higher than that of the film containing CLO. In particular, the scavenging activities of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2&prime, azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals in the ECA film containing 1% CBO were 50.45% and 99.37%, respectively. In contrast, the antimicrobial activities against Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes were superior in the ECA films with CLO. These results suggest that ECA films containing CLO or CBO can be applied as new active packaging materials.

The potential for using pretreatment with cinnamon leaf oil or juniper foliage oil to improve the durability of viscoelastic thermal compression (VTC)–treated hybrid poplar was explored in...

Endive is widely consumed in a fresh-cut form owing to its rich nutritional content. However, fresh-cut vegetables are susceptible to contamination by pathogenic bacteria. This study investigated the antibacterial activities of the combined treatment of cinnamon leaf oil emulsion containing cetylpyridinium chloride or benzalkonium chloride (CLC and CLB, respectively) as a cationic surfactant and ultrasound (US) against Listeria monocytogenes and Escherichia coli O157:H7 on endive. The combined treatment of CLC or CLB with US reduced the population of L. monocytogenes by 1.58 and 1.47 log colony forming units (CFU)/g, respectively, and that of E. coli O157:H7 by 1.60 and 1.46 log CFU/g, respectively, as compared with water washing treatment. The reduction levels of both pathogens were higher than those observed with 0.2 mg/ml sodium hypochlorite. In addition, the combined treatment showed no effect on the quality of the fresh-cut endive (FCE). In particular, the degree of browning in FCE was less for the treatment group than for the control and water washing treatment groups. Thus, cationic surfactant-based cinnamon leaf oil emulsions combined with US may be an effective washing treatment for the microbial safety of FCE.

The physical, antioxidant and antimicrobial properties of chitosan (CH)-cinnamon leaf essential oil (C) films, containing or not oleic acid (OA), were evaluated. The addition of OA led an increase in surface charge and particle size of the film-forming dispersions. This is in agreement with a greater CH adsorption on the droplets containing OA and the entrapment of C compounds in the non-polar core of the OA molecule associations. OA contributed to a better retention of C in the film during its drying, diminished the changes in colour parameters provoked by C addition and reduced the film transparency. Water vapour permeability of CH films was reduced by OA incorporation while it increased when they contained only C. Every film containing C showed antioxidant and antifungal properties, depending on the C content (the higher the C content, the greater the effect). OA reduced the antifungal effectiveness of C containing films in line with its encapsulating effect on C compounds. All the coatings were effective in extending the shelf-life of cold-stored strawberries, mainly when CH was combined with C at the ratio 1: 0.5., The authors acknowledge the financial support provided by Universitat Politecnica de Valencia (UPPTE/2012/183) and Ministerio de Ciencia e Innovacion (AGL2010-20694). Author A. Perdones acknowledges Universitat Politecnica de Valencia for a doctoral grant.

Chitosan microcapsules containing cinnamon leaf oil were formed by ionotropic gelation of chitosan by crosslinking with sodium tripolyphosphate. The microencapsulation method for oil loading was optimized by varying the amounts of polymer, oil and cross linker. The effect of varying process parameters on the encapsulation efficience (EE), oil loading capacity (LC) and release rate was monitored. The formulated microcapsules were characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). SEM imaged clear spherical shaped oil loaded microcapsules with a crimpy surface while empty capsules had a smooth texture.FTIR spectra evidence for the successful encapsulation of oil within wall material. EE increased with increasing oil load while it decreased with increasing polymer and cross linker concentration. LC increased with increasing amounts of oil and crosslinker and showed a decrease with increasing polymer amounts. Release rate of oil increased with increasing oil loading whereas it decreased with increasing polymer and crosslinker amounts. Varying the process parameters has a direct impact on the EE, LC and release rate. The optimum formulation for cinnamon oil microcapsules is polymer, 1 g : oil, 3g: cross linker, 0.5 g with an EE of 91%, and a LC of 38%.

There is generally no kill-step when preparing salad vegetables, so there is a greater risk for foodborne illness from contaminated vegetables. Some essential oils have antimicrobial activities and could provide a natural way to reduce pathogens on fresh produce. The objective of this study was to investigate the antimicrobial activity of cinnamon oil wash against Salmonella enterica serotype Newport on organic leafy greens. Organic romaine and iceberg lettuce, and organic baby and mature spinach were inoculated with Salmonella Newport and then dip treated in a phosphate buffered saline (PBS) control and 3 different concentrations (0.1, 0.3, and 0.5% v/v) of cinnamon oil. The treatment time varied at either 1 or 2min, and storage temperature varied at either 4 or 8°C. Samples were collected at days 0, 1, and 3. For romaine and iceberg lettuce, S. Newport was not recovered on day 3 for 2min 0.3% and 0.5% cinnamon oil treatments. For mature spinach, S. Newport was not recovered by day 3 for the 2min 0.3% and 0.5% 4°C treatments. For baby spinach, there was no recovery of S. Newport by day 1 for all 0.5% treatments. Overall, the cinnamon oil treatments were concentration and time dependent with higher concentrations and longer treatment times providing the greatest reduction in S. Newport population on leafy greens. In addition, the treatments had a residual effect with the greatest reduction generally seen on the last day of sampling. Storage temperature did not have a significant effect on the reduction of S. Newport. Based on the results of this study, cinnamon oil has the potential to be used as a treatment option for washing organic baby and mature spinach, and iceberg and romaine lettuces.

The objective of this study was to evaluate the antimicrobial activity of lauric arginate (LAE) when used alone or in combination with the essential oil (EO) from cinnamon leaf and EO components, thymol and eugenol. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Enteritidis were determined by the microbroth dilution method in tryptic soy broth (TSB) at their optimal growth temperatures. The MIC for LAE was 11.8ppm against L. monocytogenes and E. coli O157:H7 and 23.5ppm against S. Enteritidis. Synergistic antimicrobial activity was demonstrated against L. monocytogenes with combinations of LAE and cinnamon leaf oil or eugenol, while the LAE and thymol combination showed additive antimicrobial activity. Conversely, antagonistic effects were shown for all combinations against E. coli O157:H7 and S. Enteritidis. Beef extract, at 2 or 5% w/v in TSB, showed no effects on the MIC and MBC of LAE against L. monocytogenes, while soluble starch from potato, at 2-10% w/v in TSB, increased the MIC and MBC. When tested in 2% reduced fat milk, significantly higher levels of antimicrobials were required to achieve similar inhibitions as in TSB. The growth curves of bacteria at 21°C followed similar trends as in TSB, showing synergism against the Gram-positive L. monocytogenes and antagonism against the two Gram-negative bacteria. Findings suggest that application of LAE could enhance microbial food safety, especially when used in combination with EO to inhibit the growth of Gram-positive bacteria.

There is renewed interest in the antibacterial and antioxidant properties of essential oils as food additives. Among essential oils, cinnamon leaf oil is a potent antibacterial and antioxidant agent; however, the application in food systems can be affected by its volatility. The use of edible films is a good alternative for incorporating antibacterial agents and antioxidants into foods. This study aimed to develop an edible pectin film enriched with the essential oil from cinnamon leaves and prove that this application can increase the antioxidant status and reduce bacterial growth of fresh-cut peach. Films with different oil concentrations (0.0, 7.3, 15.7 and 36.1 oil g/l) were evaluated regarding eugenol content, thickness, moisture content, water vapour transmission, in vitro antioxidant activity and antibacterial properties of the films. No significant differences were found for the water vapour transmission among the films with different oil concentrations. The higher the added oil concentration the higher the eugenol content and antioxidant capacity; the films with 36.1 g/l were the only materials showing inhibition zones against Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes. Peaches were positively affected by the coating treatment, increasing its antioxidant status, odour acceptability and decreasing bacterial growth. These results demonstrate that the development of an edible film formulated with cinnamon leaf oil can be useful to preserve fresh-cut peach quality. Copyright © 2012 John Wiley & Sons, Ltd.

The present chapter reviews and analyzes information on the combinational approach to formulating antimicrobial and antioxidant edible films using pectin and cinnamon leaf oil (CLO). Pectin and CLO are food ingredients that are generally recognized as safe. They can be combined to formulate antioxidant and antimicrobial edible films. The use of pectin as a carrier of CLO offers stability to the oil components and facilitates their application to food systems, maintaining the bioactive properties of CLO. The use of free CLO has been effective as an antimicrobial and antioxidant agent; however, the effective concentrations can negatively affect the sensorial acceptability of the treated food. Although, when these two substances are combined to formulate an edible coating, the negative effects can be solved. The antifungal, antibacterial, and antioxidant efficacy of this combination has been tested mainly in fresh produce; nevertheless, its application can be contemplated and suggested in other types of food.

Cinnamon leaf (CLO) and garlic oils (GO) are good antimicrobials, however, their volatility complicates their application as food preservatives. Hence, microencapsulation of CLO and GO with β-cyclodextrin (β-CD) was studied at 4:96, 8:92, 12:88, and 16:84 (oil:β-CD) percent weight ratios. Microcapsule characterization included gas chromatography analysis, moisture sorption–desorption isotherms, infrared spectroscopy (IR), and antifungal activity against Alternaria alternata. Major oil constituents were eugenol for CLO and allyl disulfide for GO. The 16:84 ratio (CLO:β-CD) showed the highest eugenol content; the allyl disulfide content was higher, but not significantly different (P > 0.05) for the 12:88 and 16:84 ratios. Microcapsules showed lower moisture sorption than β-CD, although during water desorption there were no difference between them. Hydrogen bonds were detected between oil constituents and β-CD by IR spectroscopy. CLO:β-CD and GO:β-CD microcapsules displayed good antifungal activity against Alternaria alternata. Therefore, CLO and GO microcapsules can have important applications in the food industry as stable natural antimicrobial compound systems.

The composition of the volatiles from leaves of Cinnamomum zeylanicum Blume from Sri Lanka was studied by GC-FID and GC-MS. The basic component of the oil was found to be eugenol (74.9%), followed by β-caryophyllene (4.1%), benzyl benzoate (3.0%), linalool (2.5%), eugenyl acetate (2.1%) and cinnamyl acetate (1.8%). The essential leaf oil from cinnamon demonstrated scavenger activity against the DPPH radical at concentrations which are lower than the concentrations of eugenol, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). This essential cinnamon oil showed also a significant inhibitory effect on hydroxyl radicals and acted as an iron chelator. Cinnamon leaf oil efficiently inhibited the formation of conjugated dienes and the generation of secondary products from lipid peroxidation at a concentration equivalent to that of the standard BHT.

The leaf oil of Cinnamomum zeylanicum Blume grown in Little Andaman was analysed by GC and GC-MS. Forty-seven constituents, representing 99.96% of the oil, were identified. The main constituents of the oil were eugenol (76.60%), linalool (8.5%) and piperitone (3.31%). The composition of the oil is comparable to cinnamon leaf oil produced in Bangalore and Hyderabad (south India) in terms of eugenol and linalool contents.

Twenty-five essential oils were tested for antioxidant activities using a conjugated diene assay, the aldehyde/carboxylic acid assay, the DPPH free radical scavenging assay, and the malonaldehyde/gas chromatography (MA/GC) assay. They were also tested for lipoxygenase inhibitory activities using the lipoxygenase inhibitor-screening assay. Thyme oil exhibited the greatest antioxidant effect in all assays (80-100%) except in the DPPH assay (60%). Clove leaf oil showed activities comparable to those of thyme oil (53-100%). Cinnamon leaf oil showed strong activities in the aldehyde/carboxylic acid assay (100%) and DPPH assay (84%), but only moderate activities in the conjugated diene assay (24%) and MA/GC assay (48%). Basil oil exhibited a strong effect in the DPPH assay (86%) and moderate activities in the MA/GC assay (35%). Bergamot oil exhibited 100% antioxidant activity in the aldehyde/carboxylic acid assay. Eucalyptus and chamomile oils showed appreciable activities only in the conjugated diene assay. Bitter orange oil exhibited moderate antioxidant activity (53%) only in the MA/GC assay. Aloe vera oil exhibited the greatest lipoxygenase inhibitory activity (96%), followed by thyme oil (86%) and bergamot oil (85%) at a concentration of 0.5 microg/mL. Chamomile oil showed slight lipoxygenase inhibitory activity at 0.5 microg/mL but strong lipoxygenase inducing activity at 5 microg/mL (-123%). Thyme and clove leaf oils contained high levels of thymol (23%) and eugenol (77%), respectively, as a principal of the antioxidant activity. The results obtained in the present study suggest that some essential oils possess strong medicinal activities, which can be utilized for treatment of certain diseases.

Introduction – Superheated water extraction (SHWE) potentially provides an environmentally friendly and clean extraction technique which uses a minimum or no organic solvent. The scope and limitations of the technique have still to be fully explored. Objective – To investigate the application of SHWE to cinnamon (Cinnamomum zeylanicum L.) bark and leaves as typical plant materials to determine if this extraction method can yield a higher quality oil. Methodology – Samples of cinnamon bark or leaves were extracted at 200°C with water under pressure. The essential oils were obtained from the aqueous solution using a solid phase extraction cartridge and were then examined by GC-MS. Results – Using superheated water extraction, cinnamon bark oil with over 80% cinnamaldehyde and cinnamon leaf oil containing up to 98% eugenol were obtained. Alternative solvent extraction methods were also studied but led to emulsion formation apparently because of the presence of cellulose breakdown products. Conclusion – Superheated water extraction offers a cheap, environmentally friendly technique with a shorter extraction time than hydrodistillation and yielded a higher quality oil with a higher proportion of eugenol than hydrodistillation. Copyright © 2010 John Wiley & Sons, Ltd.

The leaves of Cinnamomum tamala were collected from the trees grown in Nepal and were steam distilled to obtain the volatile oil. The chemical composition of this volatile oil was examined by GC/MS method. The components in cinnamon leaf oil were constituted of linalool (54.66%), a-pinene (9.67%), p-cymene (6.43%), β-pinene (4.45%), limonene (2.64%) and sixteen minor components less than 2.0%. The percentage of cinnamaldehyde is only 1.16% and then eugenol was absent in this volatile oil. The experimental data were compared with the data of different cinnamon leaf oils which were received from literature survey.

Cinnamon leaf oil contains a high percentage of eugenol and has antimicrobial, antioxidant and antiinflammatory properties. However, the undiluted oil can cause irritation to the skin. Therefore, the aims of this study were to develop and evaluate cinnamon leaf oil nanocream using palm oil. Nanocream base was prepared using different ratios of oil, surfactants and water. The surfactant used were mixture of Tween 80:Carbitol or Tween 80:Span 65 at different hydrophile-lipophile balance values. The pseudoternary phase diagrams were constructed to identify the nanocream base areas and the results showed that the nanocream bases using Span 65 as co-surfactant produced bigger cream area. Fifteen formulations using mixtures of Tween 80:Span 65 were further evaluated for accelerated stability test, droplet size, zeta potential, rheological properties and apparent viscosity. The nanocream base which had an average droplet size of 219 nm and had plastic flow with thixotropic behavior was selected for incorporation of 2% cinnamon leaf oil. The nanocream containing cinnamon leaf oil had the average size of 286 nm and good rheological characteristics. The in vitro release study demonstrated that eugenol as the main constituent of cinnamon leaf oil was released for about 81% in 10 h. The short-term stability study conducted for 6 months showed that the cinnamon leaf oil nanocream was stable at a temperature of 25° and thus, cinnamon leaf oil nanocream is a promising natural based preparation to be used for topical application.

The present study was conducted to evaluate the efficacy of essential oils from leaf and bark of cinnamon, Cinnamomum zeylanicum in controlling Meloidogyne graminicola and their effects on rice seedlings and young rice plants. This study was done; to determine the LC 50 of essential oils of the extracts of cinnamon leaf and bark to kill 50% of second stage juveniles (J 2 ) of Meloidogyne graminicola in rice root galls; to determine the efficacy of essential oils of cinnamon; in controlling J 2 in rice seedlings and young rice plants; and on the growth of rice plants. Cinnamon bark oil sample used in the current study contained about 72% cinnamaldehyde and the leaf sample contained about 86% eugenol. LC 50 for cinnamon leaf oil and cinnamon bark oil for killing 50% of juveniles of M . graminicola in rice root galls after three days of the treatment was 0.326 ppm and 0.454 ppm respectively. Number of galls in the root system of nematode infested rice seedlings was significantly reduced when they were treated with 0.9 ppm of cinnamon leaf oil and bark oil compared to untreated controls. However, the nematicidal activity between the cinnamon leaf oil and bark oil was not significantly different. The root gall index of infested young rice plants was significantly lowered when they were treated with either cinnamon leaf oil or bark oil compared to untreated controls. It was revealed that the mean plant height and the mean number of roots of essential oil treated plants were positively correlated with the number of root galls whereas, the number of dead plants and the mean percentage chlorosis were negatively correlated. Nevertheless, the mean root length did not show any significant correlation with number of root galls. This study concludes that essential oils of cinnamon leaf which contained 86% eugenol and bark which contained 72% cinnamaldehyde are similarly effective in suppression of M. graminicola in rice seedlings and young rice plants. According to the rates of application of essential oils of cinnamon leaf and bark, none of them have significant negative effect on the plant growth. Hence, they can be used as an alternative nematicide against the rice root knot nematode, M. graminicola in early stage of rice plants. Keywords: Cinnamomum zeylanicum ; essential oils; Meloidogyne graminicola;Oryza sativa DOI: http://dx.doi.org/10.4038/josuk.v6i0.4220 J Sci.Univ.Kelaniya 6 (2011) : 45-54

The repellent effects of ten oils, Domba ( Calophyllum inophyllum L), Batu ( Solanam indicum L), leaf oil and bark oil of Cinnamon ( Cinnamomum verum Presl . ), Mustard oil ( Brassica juncea Cross.), Neem oil ( Azadiracta indica A.Juss), Mee oil ( Maduka longifolia Koenig.), Castor oil ( Ricinus communis L.), Citronella oil ( Cymbopogon nardus L.) and Sesame oil ( Sesamum indicum L.) were tested for pulse beetle ( Callosobruchus maculatus L.) in the laboratory conditions. Data were recorded on distribution, oviposition and adult emergence. Ventilated containers each with five pairs of newly emerged adults with 20 green gram seeds were exposed to different oil vapours at the rate of 200μml. Each container was fixed to a device that provided a tunnel for pulse beetle to escape from or enter into any container. Citronella oil, Neem oil, Cinnamon leaf oil and Cinnamon bark oil vapours recorded significantly lowest number of pulse beetles after infestation and their oviposition and adult emergence indicating the highest repellent action and toxic effects. Mustard oil, Domba oil, Mee oil, Castor oil and Batu oil show indications of higher repellent effect at 4DAT on the distribution of the C. maculatus. Mustard oil and Domba oil showed a lower rate oviposition than that of Mee oil, Castor oil and Batu oil. All the treatments except Sesame oil had significantly reduced adult emergence at 18DAT. Sesame oil showed positive effect on distribution, oviposition and adult emergence and no repellent activity against the C. maculatus. Key words : C. maculatus ; Green gram; Oil vapours; Repellent effects DOI: 10.4038/tare.v12i1.1978 Tropical Agricultural Research & Extension 12(1):2009 13-16

Commercial cinnamon leaf oil and bark oil distillates from commercially ground cinnamon were oxidized via immobilized riboflavin at 22°C under 1740 lumens of light in a model system. Most components of bark oil were oxidized in the model system which produced singlet oxygen. Compound disappearance was observed in cinnamon bark oil distillates with storage time of ground cinnamon. Bleached and filtered cinnamon leaf oil was resistant to oxidation in the model system. Thirty-seven water-soluble compounds in bark distillate were identified using GUMS procedures. Of these compounds 10 had not been previously reported in the literature.