Volatile composition of sweet basil essential oil (Ocimum basilicum L.) as affected by drying method

Volatile Composition of Essential Oils from Different Aromatic Herbs Grown in Mediterranean Regions of Spain

Volatile composition of essential oils from dill, parsley, coriander, and mint were investigated at different harvest dates to determine the most suitable harvest time for each these herbs. Hydrodistillation (HD), using a Deryng system, was used for isolating the essential oils. Isolation and identification of the volatile compounds were performed using gas chromatography-mass spectrometry (GC-MS) instrument. The results of gas chromatography-flame ionization detector (GC-FID) analysis (quantification) showed that the main components in the essential oil of dill shoots were α-phellandrene, dill ether, and β-phellandrene, and the optimal harvest date was D2 (second harvest, fourth week of February 2015). For parsley shoots, the main compounds were 1,3,8-p-menthatriene, β-phellandrene, and P1 (first harvest, third week of November 2014) was the sample with the highest essential oil. For coriander, the main compounds were E-2-dodecenal, dodecanal, and octane and the highest contents were found at C2 (second harvest, 5 February 2015); while, the main two components of mint essential oil were carvone and limonene, and the highest contents were found at M1 (first harvest, second week of December 2014). The present study was the first one reporting data on descriptive sensory analysis of aromatic herbs at this optimal harvest date according to the content of volatile compounds of their essential oils.

Chemical composition and antibiofilm activity of Petroselinum crispum and Ocimum basilicum essential oils against Vibrio spp. strains

In this study, we evaluated the antibacterial activity of parsley and basilic essential oils tested against Vibrio strains and their abilities to inhibit and eradicate the mature biofilm using the XTT assay. Petroselinum crispum essential oil was characterized by 1,3,8-p-menthatriene (24.2%), β-phellandrene (22.8%), apiol (13.2%), myristicin (12.6%) and terpinolene (10.3%) as a major constituents. While, in the basilic oil, linalool (42.1%), (E)-methylcinnamate (16.9%) and 1-8 cineole (7.6%) were the main ones. These two essential oils exhibit high anti-Vibrio spp. activity with varying magnitudes. All microorganisms were strongly affected indicating an appreciable antimicrobial potential of basilic with a diameter of inhibition zones growth ranging from 8.67 to 23.33 mm and MIC and MBC values ranging from (0.023-0.047 mg/ml) and (>3->24 mg/ml), respectively. The two essential oils can inhibit and eradicate the mature biofilm formed on polystyrene surface even at low concentrations, with high magnitude for Ocimum basilicum essential oil. This study gives a better insight into the anti-Vibrio activity of parsley and basilc oils and the possibility of their use to prevent and eradicate contamination of sea products by these strains.

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

Ocimum basilicum L. essential oil and its β-cyclodextrin (β-CD) complex have been investigated with respect to their stability against the degradative action of air/oxygen and temperature. This supramolecular system was obtained by a crystallization method in order to achieve the equilibrium of complexed-uncomplexed volatile compounds in an ethanol/water solution at 50 °C. Both the raw essential oil and its β-CD complex have been subjected to thermal and oxidative degradation conditions in order to evaluate the protective capacity of β-CD. The relative concentration of the O. basilicum L. essential oil compounds, as determined by GC-MS, varies accordingly with their sensitivity to the thermal and/or oxidative degradation conditions imposed. Furthermore, the relative concentration of the volatile O. basilicum L. compounds found in the β-CD complex is quite different in comparison with the raw material. An increase of the relative concentration of linalool oxide from 0.3% to 1.1%, in addition to many sesquiterpene oxides, has been observed. β-CD complexation of the O. basilicum essential oil modifies the relative concentration of the encapsulated volatile compounds. Thus, linalool was better encapsulated in β-CD, while methylchavicol (estragole) was encapsulated in β-CD at a concentration close to that of the raw essential oil. Higher relative concentrations from the degradation of the oxygenated compounds such as linalool oxide and aromadendren oxide were determined in the raw O. basilicum L. essential oil in comparison with the corresponding β-CD complex. For the first time, the protective capability of natural β-CD for labile basil essential oil compounds has been demonstrated.

Antioxidant activity, volatile composition and sensory profile of four new very-early apricots (Prunus armeniaca L.)

BACKGROUND

Very-early apricot cultivars are interesting owing to the fact that they will be available in markets before any other cultivar. In order to achieve good fruit quality, very-early apricots require appropriate size, weight and color, good balance of sugars and organic acids, proper content of bioactive compounds, relatively strong apricot aroma as well as acceptable sensory quality.

RESULTS

Physical, chemical, antioxidant and sensory properties showed important variations among apricot cultivars. These differences were basically attributed to genetic reasons. Four very-early apricot cultivars were studied, namely 'Mirlo Blanco', 'Mirlo Anaranjado', 'Colorao' and 'Mogador'. All of them showed proper size and weight, but their contents of organic acids, sugars and bioactive compounds were low and the number of volatile compounds was also low. However, very-early apricots showed an appropriate sensory profile for fresh consumption.

CONCLUSION

Regarding physical, chemical and volatile composition and sensory properties, very-early apricot cultivars could be recommended for fresh consumption. However, future research must be focused on increasing their contents of sugars, organic acids and bioactive and volatile compounds, perhaps via cultural practices such as deficit irrigation and/or mulching.

Identification and field evaluation of non-host volatiles disturbing host location by the tea geometrid, Ectropis obliqua

Volatile organic compounds derived from non-host plants, Ocimum basilicum, Rosmarinus officinalis, Corymbia citriodora, and Ruta graveolens, can be used to mask host plant odors, and are repellent to the tea geometrid, Ectropis obliqua. Volatile compounds were collected by headspace absorption, and the components were identified and quantified by using gas chromatography/mass spectrometry. The responses of antennae of female E. obliqua to the compounds were evaluated with gas chromatography/electroantennography detection. Qualitative and quantitative differences were found among the four odor profiles. Consistent electroantennographic activity was obtained for eight of the volatiles from the four plants: β-myrcene, α-terpinene, γ-terpinene, linalool, cis-verbenol, camphor, α-terpineol, and verbenone. In a Y-tube bioassay, six chemicals, β-myrcene, γ-terpinene, (R)-(-)-linalool, (S)-(-)-cis-verbenol, (R)-(+)-camphor, and (S)-(-)-verbenone, were the main compounds responsible for repelling E. obliqua. An eight-component mixture including all of the bioactive compounds (in a ratio of 13:2:13:8:1:24:6:17) from R. officinalis was significantly more effective at repelling the moths than any single compound or a mixture of equal amounts of the eight compounds. Field results demonstrated that intercropping tea plants with R. officinalis effectively suppressed E. obliqua infestations in a tea plantation. Our findings suggests that odor blends of R. officinalis play a role in disturbing host orientation behavior, and in repelling E. obliqua adults, and that R. officinalis should be considered when developing "push-pull" strategies aimed at optimizing the control of E. obliqua with semiochemicals.