Chemical composition and insecticidal properties of some aromatic herbs essential oils from Algeria

Food Chemistry 129 (2011) 179–182

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Chemical composition and insecticidal properties of some aromatic herbs essential oils from Algeria Safia Zoubiri a,b,c,⇑, Aoumeur Baaliouamer a a Laboratory of Functional Organic Analysis, Faculty of Chemistry, University of Sciences and Technology Houari Boumediene, BP32, El-Alia, Bab-Ezzouar, 16111 Algiers, Algeria b Research and Development Center, EPE Aldar, Moubydal Group, Dar El-Beida, Algeria c Scientific and Technological Research Center on Physical and Chemical Analysis (CRAPC), Bou-Ismail site, Tipaza, Algeria

a r t i c l e

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Article history: Received 28 July 2010 Received in revised form 18 February 2011 Accepted 12 April 2011 Available online 19 April 2011 Keywords: Foeniculum vulgare Rosmarius officinalis Lippia citriodora Sitophilus granarius Activity

a b s t r a c t The biological effects on Sitophilus granarius were evaluated for three aromatic herbs essential oils: Foeniculum vulgare, Rosmarius officinalis and Lippia citriodora. Stored grain pests were currently controlled by chemical pesticides. This control method leads to pollution of the environment and intoxication of consumers. Essential oils of aromatic plants are more considered as good control alternative tools. Filter papers treated with 5, 50 and 500 ll of test oil were placed in the bottom cover of 1 l plastic bottle. The insects, 50 adults per bottle, were exposed for 1–5 days. Cumulative mortalities were determined 24 and 120 h after treatment. All treatments were replicated five times. The components of the essential oils were identified through GC and GC–MS. The identity of the constituents was confirmed and their relative proportions determined. The results indicate that these natural products may find potential application as useful, environmentally safe insect control and crop protectant agents. Ó 2011 Elsevier Ltd. All rights reserved.

1. Introduction Numerous plants have been demonstrated to produce pesticidal compounds, either as a chemical defence mechanism against predation or infection (Ciccia, Coussio, & Mongelli, 2000). Essential oils can also be used as functional ingredients. Several studies have documented the anti-oxidant, anti-microbial, anti-viral, antiinflammatory, anti-ulcerous and anti-carcinogenic properties of plant essential oils (Viuda-Martos, Ruiz-Navajas, Fernandez-Lopez, & Perez-Alvarez, 2010). Over 2000 species of plants are known to possess some insecticidal activity. In many cases the plants have a history of usage as folk remedies and are still used to kill or repel insects (Broussalis et al., 1999). Investigations in several countries confirm that some plant essential oils not only repel insects, but have contact and fumigant insecticidal actions against specific pests, and fungicidal actions against some important plant pathogens (Isman, 2000). Contact and fumigant insecticidal actions of plant essential oils have been well demonstrated against stored product pests. Some essential oils have acute toxicity, repellent action, feeding inhibition or harmful effects on the reproductive system of insects (Prates et al., 1998). ⇑ Corresponding author at: Laboratory of Functional Organic Analysis, Faculty of Chemistry, University of Sciences and Technology Houari Boumediene, BP32, ElAlia, Bab-Ezzouar, 16111 Algiers, Algeria. E-mail address: safi[email protected] (S. Zoubiri). 0308-8146/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2011.04.033

Environmentally stored-product control agents are urgently needed to replace synthetic pesticides that are ineffective, due to the increasing difficulty of managing pesticide resistance (Ukeh, Birkett, Pickett, Bowman, & Luntz, 2009). The number of confirmed resistant insect and mite species to synthetic pesticides has continued to rise, apart from risks associated with the use of these chemicals (Aslan, Özbek, Çalmasur, & SahInn, 2004). Stored products are attacked by more than 600 species of beetle pests, 70 species of moths and about 355 species of mites causing quantitative and qualitative losses (Rajendran & Sriranjini, 2008). Extracts and components from more than 75 plant species belonging to different families have been studied for fumigant toxicity. In industrialised countries, essential oils could be useful alternatives to synthetic insecticides in organic food production, while in developing countries, they can be a means of low cost protection (Cosimi, Rossi, Cioni, & Canale, 2009). Aromatic plants are among the most efficient insecticides of botanical origin and essential oils often constitute the bioactive fraction of plant extracts (Cosimi et al., 2009). Alternatives to conventional fumigants and contact insecticides are needed, because many are being banned from the market. Botanicals could have a role in replacing them to control stored rice pests. Several Mediterranean herbs have been reported to have various medicinal properties (Knio, Usta, Dagher, Zournajian, & Kreydiyyeh, 2008). Plant essential oils in general have been recognised as an important natural resource of insecticides (Bajpai, Shukla, & Kang, 2008).

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Generally, they are safe to humans and other mammals (Prajapati, Tripathi, Aggarwal, & Khanuja, 2005). Fennel (Foeniculum vulgare Mill.) is a hardy, perennial, Umbelliferous herb generally considered native to the Mediterranean areas that has become widely naturalised elsewhere; actually it may be found growing feral in many parts of the world. Fennel is highly aromatic with a characteristic aniseed flavour (Barros, Carvalho, & Ferreira, 2010). Fennel has been known, since antiquity, as a medicinal and aromatic herb. The fennel fruits contain essential oil in the mericarp. They are official in the pharmacopoeias of most of the countries. Fennel oil is a rich source of anethol and is largely used as a flavouring agent in culinary preparations, confectionary, cordials and liqueurs and occasionally employed in scenting soaps (Kapoor, Giri, & Mukerji, 2004). Moreover, the oil is used as an ingredient of cosmetic and pharmaceutical products for its balsamic, cardiotonic, digestive, lactagogue and tonic properties (Damjanovic, Lepojevic, Zivkovic, & Tolic, 2005). Verbenaceae includes approximately 200 species of herbs, shrubs and small trees (Argyropoulou, Daferera, Tarantilis, Fasseas, & Polissiou, 2007). Most of them are traditionally utilised as remedies for gastrointestinal and respiratory problems. Some species have shown antimalarial, antiviral and cytostatic properties. It is believed that their essential oils and phenolic compounds are responsible for these properties (Bilia, Giomi, Innocenti, Gallori, & Vincieri, 2008). Verbena leaves’ are largely used as herbal tea for their aromatic, digestive and antispasmodic properties (Carnat, Carnat, Fraisse, & Lamaison, 1999). Rosemary, (Rosmarius officinalis L.), of the family Labiatae, is an aromatic shrub with an intense pleasant smell reminiscent of pine wood. Rosemary is cultivated mainly in Mediterranean countries, such as Spain, Morocco, Tunisia, France and Italy (Szumny, Figiel, Gutierrez-Ortiz, & Carbonell-Barrachin, 2010). It is used as a food flavouring agent and known medicinally for its powerful antimutagenic and antibacterial properties, and as a chemopreventive agent. The plant is also known for its powerful antioxidant activity (Okoh, Sadimenko, & Afolayan, 2010). Rosemary essential oil is also used as an antifungal agent (Rezzoug, Boutekedjiret, & Allaf, 2005). The aim of this study is to identify the chemical composition by GC and GC–MS and evaluate the fumigant activity of some essential oils extracted from three plants of the Mediterranean flora: fennel (F. vulgare), verbena (Lippia citriodora) and rosemary (R. officinalis) tested on Sitophilus granarius. The reason of the selection of S. granarius for the present screening is based on its economic importance. S. granarius is a serious pest which destroys storedproduct (Broussalis et al., 1999). This idea is not new, in fact, it has been used indirectly in the developing countries to preserve grains in traditional storage (Lopez, Jordan, & Pascual-Villalobos, 2008). 2. Materials and methods 2.1. Plant material F. vulgare seeds, L. citriodora leaves and R. officinalis aerial parts were collected during May 2007 from cultivated plants in Sétif (300 km east of Algiers, 1096 m above sea level, coordinates: 36°110 N 5°240 E), Blida (45 km north of Algiers, 190 m above sea level, coordinates: 36°290 N 2°500 E) and the botanical garden of the University of Sciences and Technology (Bab Ezzouar, a suburb of the city of Algiers, coordinates: 36°430 N 3°110 E), respectively. 2.2. Essential oil isolation Fresh F. vulgare seeds, L. citriodora leaves and R. officinalis aerial part’s (300 g  10) were subjected to hydrodistilation for 3 h in a

Clevenger-type apparatus. The resulting essential oil was dried over anhydrous sodium sulphate and stored at +4 °C until use. 2.3. GC-FID and GC–MS analysis Analytical gas chromatography was carried out on a Hewlett– Packard 6890 gas chromatograph equipped with a flame ionization detector. An apolar HP-5 column (30 m, 0.32 mm, 0.25 lm film thickness) was used. The flow of the carrier gas (Helium) was 1 ml/min. The split ratio was 50:1. The analysis was performed using the following temperature program: oven isotherm at 40 °C for 8 min, from 40 to 250 °C at the rate of 2 °C/min and isotherm at 250 °C during 5 min. Injector and detector temperatures were held, respectively, at 250 °C. The injection volume was 0.5 ll. GC–MS analysis was performed on a gas chromatograph HP 6890 equipped with a HP 5973 mass spectrometer with electron ionization (70 eV). A HP-5MS capillary column (30 m, 0.25 mm, 0.25 lm film thickness) was used. The GC conditions were the same described above. 2.4. Compounds identification The identification of the oil constituents was based on a comparison of their retention indices relative to (C6–C27) n-alkanes with those in the literature (Adams, 2007). Further identification was made by matching their recorded mass spectra with those stored in the NIST mass spectral library of the GC–MS data system. The quantitative data were obtained from the FID electronic integration peak areas. 2.5. Insect cultures S. granarius was reared in 1 l glass jars containing chickpea grains, which were covered by fine mesh cloth for ventilation. Adult insects, 1–7 days old, were used for the fumigation toxicity test. All experimental procedures were conducted under environmental conditions identical to those of the cultures. 2.6. Fumigant toxicity bioassay A filter paper treated with an appropriate concentration (5–500 ll/l air) of test essential oil in acetone. The impregnated filter paper was then placed in the bottom cover of a plastic bottle of 1 l. The insects, 50 adults with undefined sex per bottle, were exposed for 1–5 days. The cumulative mortalities were determined 24 and 120 h after treatment. All treatments were replicated five times. The percentage insect mortalities are provided as the mean of five measurements. Standard deviations (SD) were in the range of 3–10%. The standard deviations were calculated using spreadsheet software (ExcelÒ). 3. Results and discussion 3.1. Chemical constituents of essential oil The constituents identified by GC–MS analysis, in order of elution on HP-5 and the quantitative data (GC-FID peak area percentages without correction factors) are presented in Table 1. In addition, Table 1 summarises previous investigations of authors on the analysis of the volatile oils from L. citriodora (Gillij, Gleiser, & Zygadlo, 2008), F. vulgare (Napoli, Curcuruto, & Ruberto, 2010b; Telci, Demirtas, & Sahin, 2009), and R. officinalis (Gachkar et al., 2007; Napoli, Curcuruto, & Ruberto, 2010a). The yield of the volatile fraction obtained through hydrodistilation was 0.36%, 1.21% and 0.50% for L. citriodora, F. vulgare and R. officinalis, respectively.

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S. Zoubiri, A. Baaliouamer / Food Chemistry 129 (2011) 179–182 Table 1 Chemical composition of essential oils from Lippia citriodora, Rosmarius officinalis and Foeniculum vulgare (in %) as reported in the literature. Compound

a-Pinene

L. citriodora

R. officinalis

F. vulgare

Ps

P1

Ps

P2

P3

P4

Ps

P5

P6

0.76 – 1.54 – 1.26 – – – 17.72 – – – – – – 1.37 – – 14.22

12.59 4.30 2.16 – – 1.18 1.99 13.46 1.20 3.10 11.75 9.41 3.13 – 0.99 1.32 8.29 – – – – – 4.24 – – 2.83 – – – 0.71 – – –

11.47 5.70 1.12 – – 1.25 – 11.91 – 2.02 16.57 5.74 – – 1.42 – 17.43 – – – – – 9.19 – – – – – – – – – –

14.50 3.80 2.50 – – 1.60 – 50.90 – 0.60 12.10 3.60 – – 1.00 4.10 – – – – – – 0.40 – – 0.90 – – – – – – –

14.90 3.33 – 1.61 – 2.07 – 7.43 – 14.90 4.97 3.68 – – 1.70 0.83 1.94 – – – – – 3.08 – – 2.68 1.26 – – – – – 1.01

1.22 0.19 – – – – – – 6.37 – – – – 12.93 – – – 3.41 – – – 72.86 – – – – – – – – – – –

1.30 0.10 0.10 – – 0.50 – 0.20 1.40 – 0.40 – – 18.00 0.10 – – 76.80 – – – 0.70 – – – – – – – – – – –

0.12 – 0.05 – – 0.38 – – 2.96 – – – – 1.19 0.95 – – 5.16 – – – 87.85 – – – – – – – – – – –

Camphene b-Pinene 3-Octanone 2-Octanone Myrcene 3-Carene Eucalyptol Limonene Linalool Camphor Borneol Isoborneol Fenchone Terpinen-4-ol a-Terpineol Verbenone Estragol Carvone Neral Geranial trans-Anethol Bornyl acetate a-Thujone Geranyl acetate b-Caryophyllene cis-beta-Farnesene ar-Curcumene trans-Nerolidol Caryophyllene oxide Spathulenol Bicyclosesquiphellandrene a-Bisabolol

14.79 – – – 1.07 1.39 – 6.35 1.53 12.38 1.17 2.04 –

1.10 0.50 – – – – – – 7.00 0.50 5.20 1.20 – – 0.40 0.40 – – 0.80 19.40 22.70 – – 14.20 – 0.40 – – 0.50 0.90 0.90 – –

Monoterpenes hydrocarbons Sesquiterpenes hydrocarbons Oxygenated monoterpenes Oxygenated sesquiterpenes Others

20.02 9.78 43.83 2.70 1.26

8.60 0.40 65.70 1.40 –

23.42 2.83 56.40 – –

19.54 – 64.28 – –

22.40 0.90 72.70 – –

20.30 3.94 38.53 1.01 1.61

7.78 – 12.93 – 76.27

3.40 – 18.70 – 77.50

3.51 – 2.14 – 93.01

Total listed Total identified

77.59 95.18

76.10 –

82.65 95.37

83.82 90.15

96.00 –

65.39 –

96.98 98.65

99.60 –

98.66 99.70

Ps: present study, P1: Gillij et al. (2008), P2: Okoh et al. (2010), P3: Napoli et al. (2010a), P4: Gachkar et al. (2007), P5: Napoli et al. (2010b), P6: Telci et al. (2009), ‘–’: nondetected.

The chemical composition of the essential oil of L. citriodora leaves was different from that observed from Argentinean plant materials (Gillij et al., 2008). The comparison of our results with literature shows some qualitative and quantitative differences in the composition of the oil. It was dominated by oxygenated monoterpenes (43.83% versus 65.70%, Gillij et al., 2008). The major components were limonene (17.72% versus 7.00%, Gillij et al., 2008), geranial (14.79% versus 22.70%, Gillij et al., 2008), carvone (14.22% versus 0.80%, Gillij et al., 2008) and caryophyllene oxide (12.38% versus 0.90%, Gillij et al., 2008). The oxygenated monoterpenes, such as camphor (5.20%), neral (19.40%) and a-thujone (14.20%) (Gillij et al., 2008) were not found in our essential oil. The F. vulgare seeds essential oil was made up largely of phenylpropanoids. trans-Anethol was the main component of the oil with rate of 72.86% versus 0.70% (Napoli et al., 2010b) and 87.85% (Telci et al., 2009). The component was followed by fenchone (12.93% versus 18.00%, Napoli et al., 2010b) and 1.19% (Telci et al., 2009). Limonene (6.37% versus 1.40%, Napoli et al., 2010b) and 2.96% (Telci et al., 2009), estragol (3.41% versus 76.80%, Napoli et al., 2010b) and 5.16% (Telci et al., 2009) and a-pinene (1.22% versus 1.30%, Napoli et al., 2010b) and 0.12% (Telci et al., 2009) are other components identified in the fennel oil. trans-Anethol and estragol are often the main fennel oil components. They are isomers with the only difference being the position of the double bound of the

propenyl chain. While trans-anethol is the main component in the studied oil, estragol constitutes the main component in the Turkish one (Telci et al., 2009). The R. officinalis areal part essential oil was characterised by a high content of oxygenated monoterpenes (56.40% versus 64.28%, Okoh et al., 2010), 72.70% (Napoli et al., 2010a), 38.35% (Gachkar et al., 2007). The major constituents were eucalyptol (13.46% versus 11.91%, Okoh et al., 2010), 50.90% (Napoli et al., 2010a), 7.43% (Gachkar et al., 2007), a-pinene (12.56% versus 11.47%, Okoh et al., 2010), 14.50% (Napoli et al., 2010a), 14.90% (Gachkar et al., 2007), camphor (11.75% versus 16.57%, Okoh et al., 2010), 12.10% (Napoli et al., 2010a), 4.97% (Gachkar et al., 2007), borneol (9.41% versus 5.74%, Okoh et al., 2010), 3.60% (Napoli et al., 2010a), 3.68% (Gachkar et al., 2007) and verbenone (8.29% versus 17.43%, Okoh et al., 2010), 1.94% (Gachkar et al., 2007). Compounds, such as isoborneol (3.13%), 3-carene (1.99%), limonene (1.20%) and caryophyllene oxide (0.71%) were detected only in our essential oil. 3.2. Fumigant toxicity For 24 and 120 h fumigation, the mortalities at concentrations of 5, 50 and 500 ll/l air of L. citriodora, F. vulgare and R. officinalis essential oil for S. granarius are shown in Fig. 1. Concentrations of 5, 50 and 500 ll/l air showed (0, 0, 0), (19, 25, 39) and (21, 30,

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Fig. 1. Mortality of Sitophilus granarius resulting from 24 to 120 h fumigation with different dosages of Foeniculum vulgare (Fo), Rosmarius officinalis (Ro) and Lippia citriodora (Lc) essential oils.

59) % kill after 24 h fumigation for L. citriodora, F. vulgare and R. officinalis essential oils, respectively. For 120 h fumigation, oil concentrations at 5 ll/l showed 50% mortality for the three plants oils. Complete controls can be achieved by treating air with 50 ll/l of F. vulgare or R. officinalis essential oil for 120 h. Moreover, the control of the half insect population was guaranteed using concentration of 5 ll/l after 120 h fumigation for the three studied essential oils. This percentage control could be achieved using 500 ll/l of R. officinalis essential oil for 24 h fumigation. However, when developing a new fumigant to meet regulatory requirements, it is necessary to have an understanding of the toxicity of the fumigant to the target insect pests (Lee, Annis, & Tumaali, 2003). The F. vulgare or R. officinalis essential oil show promise as a fumigant. Nevertheless, field trials with suitable formulations need to be carried out to further assess the efficacies of these essential oils. It would be interesting to determine the lowest concentration of these essential oils at which they are still effective as fumigants, and to study the effects of combining components to identify potential synergisms and antagonisms (Gillij et al., 2008). References Adams, R. P. (2007). Identification of essential oil components by gas chromatography/ mass spectroscopy. Carol Stream, Illinois: Allured Publishing Corporation. Argyropoulou, C., Daferera, D., Tarantilis, P. A., Fasseas, C., & Polissiou, M. (2007). Chemical composition of the essential oil from leaves of Lippia citriodora H.B.K. (Verbenaceae) at two developmental stages. Biochemical Systematics and Ecology, 35, 831–837. Aslan, I., Özbek, H., Çalmasur, Ö., & SahInn, F. (2004). Toxicity of essential oil vapours to two greenhouse pests, Tetranychus urticae Koch and Bemisia tabaci Genn. Industrial Crops and Products, 19, 167–173. Bajpai, V. K., Shukla, S., & Kang, S. C. (2008). Chemical composition and antifungal activity of essential oil and various extract of Silene armeria L. Bioresource Technology, 99, 8903–8908. Barros, L., Carvalho, A. M., & Ferreira, I. C. F. R. (2010). The nutritional composition of fennel (Foeniculum vulgare): shoots, leaves, stems and inflorescences. LWT – Food Science and Technology, 43, 814–818. Bilia, A. R., Giomi, M., Innocenti, M., Gallori, S., & Vincieri, F. F. (2008). HPLC–DAD– ESI-MS analysis of the constituents of aqueous preparations of verbena and lemon verbena and evaluation of the antioxidant activity. Journal of Pharmaceutical and Biomedical Analysis, 46, 463–470. Broussalis, A. M., Ferraro, G. E., Martino, V. S., Pinzon, R., Coussio, J. D., & Alvarez, J. C. (1999). Argentine plants as potential source of insecticidal compounds. Journal of Ethnopharmacology, 67, 219–223.

Carnat, A., Carnat, A. P., Fraisse, D., & Lamaison, J. L. (1999). The aromatic and polyphenolic composition of lemon verbena tea. Fitoterapia, 70, 44–49. Ciccia, G., Coussio, J., & Mongelli, E. (2000). Insecticidal activity against Aedes aegypti larvae of some medicinal South American plants. Journal of Ethnopharmacology, 72, 185–189. Cosimi, S., Rossi, E., Cioni, P. L., & Canale, A. (2009). Bioactivity and qualitative analysis of some essential oils from Mediterranean plants against storedproduct pests: evaluation of repellency against Sitophilus zeamais Motschulsky, Cryptolestes ferrugineus (Stephens) and Tenebrio molitor (L.). Journal of Stored Products Research, 45, 125–132. Damjanovic, B., Lepojevic, Z., Zivkovic, V., & Tolic, A. (2005). Extraction of fennel (Foeniculum vulgare Mill.) seeds with supercritical CO2: comparison with hydrodistillation. Food Chemistry, 92, 143–149. Gachkar, L., Yadegari, D., Rezaei, M. B., Taghizadeh, M., Astaneh, S. A., & Rasooli, I. (2007). Chemical and biological characteristics of Cuminum cyminum and Rosmarinus officinalis essential oils. Food Chemistry, 102, 898–904. Gillij, Y. G., Gleiser, R. M., & Zygadlo, J. A. (2008). Mosquito repellent activity of essential oils of aromatic plants growing in Argentina. Bioresource Technology, 99, 2507–2515. Isman, M. B. (2000). Plant essential oils for pest and disease management. Crop Protection, 19, 603–608. Kapoor, R., Giri, B., & Mukerji, K. G. (2004). Improved growth and essential oil yield and quality in Foeniculum vulgare mill on mycorrhizal inoculation supplemented with P-fertilizer. Bioresource Technology, 93, 307– 311. Knio, K. M., Usta, J., Dagher, S., Zournajian, H., & Kreydiyyeh, S. (2008). Larvicidal activity of essential oils extracted from commonly used herbs in Lebanon against the seaside mosquito, Ochlerotatus caspius. Bioresource Technology, 99, 763–768. Lee, B.-H., Annis, P.C., & Tumaali, F. (2003). The potential of 1,8-cineole as a fumigant for stored wheat, Proceedings of the Australian Post harvest Technical Conference, Canberra, 230–234. Lopez, M. D., Jordan, M. J., & Pascual-Villalobos, M. J. (2008). Toxic compounds in essential oils of coriander, caraway and basil active against stored rice pests. Journal of Stored Products Research, 44, 273–278. Napoli, E. M., Curcuruto, G., & Ruberto, G. (2010a). Screening of the essential oil composition of wild Sicilian rosemary. Biochemical Systematics and Ecology. doi:10.1016/j.bse.2010.04.001. Napoli, E. M., Curcuruto, G., & Ruberto, G. (2010b). Screening the essential oil composition of wild Sicilian fennel. Biochemical Systematics and Ecology, 38, 213–223. Okoh, O. O., Sadimenko, A. P., & Afolayan, A. J. (2010). Comparative evaluation of the antibacterial activities of the essential oils of Rosmarinus officinalis L. obtained by hydrodistillation and solvent free microwave extraction methods. Food Chemistry, 120, 308–312. Prajapati, V., Tripathi, A. K., Aggarwal, K. K., & Khanuja, S. P. S. (2005). Insecticidal, repellent and oviposition-deterrent activity of selected essential oils against Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. Bioresource Technology, 96, 1749–1757. Prates, H. T., Santos, J. P., Waquil, J. M., Fabris, J. D., Oliveira, A. B., & Foster, J. E. (1998). Insecticidal activity of monoterpenes against Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst). Journal of stored product Research, 34(4), 243–249. Rajendran, S., & Sriranjini, V. (2008). Plant products as fumigants for stored-product insect control. Journal of Stored Products Research, 44, 126–135. Rezzoug, S. A., Boutekedjiret, C., & Allaf, K. (2005). Optimization of operating conditions of rosemary essential oil extraction by a fast controlled pressure drop process using response surface methodology. Journal of Food Engineering, 71, 9–17. Szumny, A., Figiel, A., Gutierrez-Ortiz, A., & Carbonell-Barrachin, A. A. (2010). Composition of rosemary essential oil (Rosmarinus officinalis) as affected by drying method. Journal of Food Engineering, 97, 253–260. Telci, I., Demirtas, I., & Sahin, A. (2009). Variation in plant properties and essential oil composition of sweet fennel (Foeniculum vulgare Mill.) fruits during stages of maturity. Industrial Crops and Products, 30, 126–130. Ukeh, D. A., Birkett, V., Pickett, J. A., Bowman, A. S., & Luntz, A. J. M. (2009). Repellent activity of alligator pepper, Aframomum melegueta, and ginger, Zingiber officinale, against the maize weevil, Sitophilus zeamais. Phytochemistry, 70, 751–758. Viuda-Martos, M., Ruiz-Navajas, Y., Fernandez-Lopez, J., & Perez-Alvarez, J. A. (2010). Effect of adding citrus fibre washing water and rosemary essential oil on the quality characteristics of a bologna sausage. LWT – Food Science and Technology, 43, 958–963.