Volatile compounds from three cultivars of Olea europaea from Italy

Chemical composition and antimicrobial activity of essential oils of two wild olive subspecies Olea europaea L.var. sylvestris and the endemic olive Olea europaea subsp. lapperinie from Algeria

Two wild olive subspecies are fixed in this research: Olea europaea L.var. sylvestris and Olea europaea subsp. laperrinei despite its ecological value, the chemical composition of subsp. laperrinei oil remains unknown. The samples were harvested from the different geographical area. Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-flame-ionization detection (GC-FID) analysis of Olea europaea L. var. sylvestris allowed the identification of 29 compounds oil with Nonanal (11.82%), theaspiranea A (9.81%), 3-hexen-1-ol,benzoate(9.31%) as a major constituents, while in the subspecies of the Saharan region 31 compounds were separated, where α-pinene (16%), β-Ocimene (12.82%), dl-Limonene (8.20%) were the main components. The results of the disc diffusion method showed that the two volatile oils have efficient antibacterial activity but, subsp. laperrinei essential oil has a higher range of inhibition, in which P. aeruginosa and B. subtilis showed an extreme sensitivity, while the K. pneumoniae bacterium shows a great resistance to the two essential oils.

Influence of Chabazite Zeolite Foliar Applications Used for Olive Fruit Fly Control on Volatile Organic Compound Emission, Photosynthesis, and Quality of Extra Virgin Olive Oil

The olive fruit fly (Bactrocera oleae Rossi) is the most dangerous pest of olive fruits and negatively influences the chemical and sensory quality of the oil produced. Organic farms have few tools against this pest and are constantly looking for effective and sustainable products such as geomaterials, i.e., zeolite. Since a particle film covers the canopy, a study was carried out on the olive tree's responses to zeolite foliar coating. The tested treatments were natural zeolite (NZ), zeolite enriched with ammonium (EZ), and Spintor-Fly® (SF). EZ was associated with higher photosynthetic activity with respect to the other treatments, while no differences were found between SF and NZ. Foliar treatments affect the amount of BVOC produced in both leaves and olives, where 26 and 23 different BVOCs (biogenic volatile organic compounds) were identified but not the type of compounds emitted. Foliar treatment with EZ significantly affected fruit size, and the olive fruit fly more frequently attacked the olives, while treatment with NZ had olives with similar size and attack as those treated with Spintor-Fly®; no difference in oil quantity was detected. Oil produced from olives treated with NZ presented higher values of phenolic content and intensities of bitterness and spiciness than oils from those treated with EZ and SF. According to the results of this study, using zeolite films on an olive tree canopy does not negatively influence plant physiology; it has an impact on BVOC emission and the chemical and sensory characteristics of the oil.

Infestation of the gall midge Dasineura oleae provides first evidence of induced plant volatiles in olive leaves

In this study, we present the first characterization of herbivore-induced plant volatiles (HIPVs) released from infested olive leaves. The gall midge Dasineura oleae is a specific pest of Olea europaea and endemic of the Mediterranean Basin, an area in which severe outbreaks currently occurred. Little is known about the damage caused by the pest and the relationship with its host. Since gall formation and larval feeding activity may lead to the release of specific plant volatile compounds, we investigated the volatile profiles emitted from infested plants compared with healthy plants under both laboratory and field conditions. Additionally, the volatiles emitted from mechanically damaged plants were considered. A blend of 12 volatiles was emitted from olive trees infested by D. oleae. Of these, β-copaene, β-ocimene, cosmene, unknown 1 and unknown 3 were found to be exclusively emitted in infested plants. The emission of germacrene-D, (E,E)-α-farnesene, and (Z,E)-α-farnesene, α-copaene, (E)-4,8-dimethylnona-1,3,7-triene, (E)-β-guaiene and heptadecane significantly increased in infested trees. Linalool, β-copaen-4-α-ol, β-bourbonene, β-cubebene, β-elemene, β-copaene and δ-amorphene were found only in the field trial and showed differences depending on the level of infestation and the plant stage. (Z)-3-Hexenol, (E)-4-oxohen-2-enal, and 2-(2-butoxyethoxy)-ethanol, were exclusively emitted from the leaves after mechanical damage. In a field trial in Italy, we also demonstrated spring synchronization between adults of D. oleae and O. europaea trees. Analyses of morphoanatomical malformations of gall leaves showed that tissue alterations occur at the spongy parenchyma causing an increase of the leaf blade thickness. We speculate that tissue alterations may lead to HIPV release, in turn potentially attracting D. oleae natural enemies.

Essential Oil Volatile Fingerprint Differentiates Croatian cv. Oblica from Other Olea europaea L. Cultivars

Olive leaves are a highly available by-product from table olive and olive oil production. They are nowadays strongly valuable for their major bioactive compounds and their beneficial effects. To determine the differences between two Croatian domestic (Lastovka, Oblica) and two introduced (Leccino, Frantoio) cultivars, physical and chemical analysis of olive leaves were performed: surface area, color variability, total phenolic amounts, and essential oil volatile profiles were analyzed at three harvest periods. All cultivars greatly differed in surface area, with cv. Lastovka being the smallest. Color variability resulted in an overall decrease in darkness and amounts of green and yellow that could be attributed to a decrease in photosynthetic demand and chlorophyll content. The highest amount of total phenolic content occurred in the summer months, followed by a reduction until October. Essential oils volatiles were determined by GC-MS and showed great diversity not only amongst cultivars but also between harvest periods, with overall 45 compounds identified. Principal component analysis distinguished domestic cultivar Oblica from the other observed cultivars, mainly due to its essential oil volatile fingerprint. Compounds that differentiated cv. Oblica were aldehydes ((E,Z)-2,4-heptadienal, (E,E)-2,4-heptadienal, decanal), ketones ((E)-β-damascone, dihydrodehydro-β-ionone), sesquiterpenes (cyclosativene, α-copaene, α-muurolene) and saturated hydrocarbons (tetradecane, hexadecane). Essential oil volatile fingerprint attributed the highest to the biodiversity of domestic cv. Oblica through all three harvest periods.

Trichoderma Strains and Metabolites Selectively Increase the Production of Volatile Organic Compounds (VOCs) in Olive Trees

Plants emit volatile organic compounds (VOCs) that induce metabolomic, transcriptomic, and behavioral reactions in receiver organisms, including insect pollinators and herbivores. VOCs’ composition and concentration may influence plant-insect or plant-plant interactions and affect soil microbes that may interfere in plant-plant communication. Many Trichoderma fungi act as biocontrol agents of phytopathogens and plant growth promoters. Moreover, they can stimulate plant defense mechanisms against insect pests. This study evaluated VOCs’ emission by olive trees (Olea europaea L.) when selected Trichoderma fungi or metabolites were used as soil treatments. Trichoderma harzianum strains M10, T22, and TH1, T. asperellum strain KV906, T. virens strain GV41, and their secondary metabolites harzianic acid (HA), and 6-pentyl-α-pyrone (6PP) were applied to olive trees. Charcoal cartridges were employed to adsorb olive VOCs, and gas chromatography mass spectrometry (GC-MS) analysis allowed their identification and quantification. A total of 45 volatile compounds were detected, and among these, twenty-five represented environmental pollutants and nineteen compounds were related to olive plant emission. Trichoderma strains and metabolites differentially enhanced VOCs production, affecting three biosynthetic pathways: methylerythritol 1-phosphate (MEP), lipid-signaling, and shikimate pathways. Multivariate analysis models showed a characteristic fingerprint of each plant-fungus/metabolite relationship, reflecting a different emission of VOCs by the treated plants. Specifically, strain M10 and the metabolites 6PP and HA enhanced the monoterpene syntheses by controlling the MEP pathway. Strains GV41, KV906, and the metabolite HA stimulated the hydrocarbon aldehyde formation (nonanal) by regulating the lipid-signaling pathway. Finally, Trichoderma strains GV41, M10, T22, TH1, and the metabolites HA and 6PP improve aromatic syntheses at different steps of the shikimate pathway.

Biochar-derived smoke-water exerts biological effects on nematodes, insects, and higher plants but not fungi

The pyrolysis of organic feedstock yields the solid fraction biochar, bio-oils, and a volatile fraction that can be reused for energetic purposes or technological applications in agro-ecosystems in the form of smoke-water (SW). In this study, 10 SW types were created from five organic feedstocks (i.e. cellulose, wood sawdust, olive mill residues, maize, and alfalfa litter) at two pyrolysis temperatures (i.e. 300 and 500 °C). We characterized SW using liquid chromatography (LC)-electrospray ionization-time-of-flight (TOF) mass spectrometry (MS) combined with a multi-species bioassay including five crop plants, four fungi, one root-knot nematode (Meloidogyne incognita), and the olive fly pest (Bactrocera oleae). All SW types were acidic, exhibiting a pH range of 1.9-4.6. LC-MS analysis revealed differences in the chemical profiles of SW types in relation to the organic feedstock type and pyrolysis temperature. All SW types exerted concentration-dependent effects on crops, with evident phytotoxic activity at high concentrations. Conversely, they exerted stimulatory effects when diluted with water at ratios ranging from 1:100 to 1:1000. Moreover, all SW types displayed slight or null fungitoxic activity. On the contrary, SW strongly inhibited egg hatching by M. incognita after 72 and 144 h of incubation. The strongest inhibition was found for olive mill SW, and the weakest effect was noted for alfalfa SW. Finally, the application of SW over fresh olives reversed the attraction of B. oleae adults, demonstrating a strong repellent effect toward this pest. Nevertheless, only olive mill SW consistently attracted B. oleae. In conclusion, biochar SW exhibited notable biological activities and potential applications for plant growth promotion, if opportunely diluted, and for the control of root-knot nematodes and olive fruit flies.

Cold-Pressing Olive Oil in the Presence of Cryomacerated Leaves of Olea or Citrus: Nutraceutical and Sensorial Features

The nutraceutical properties of extra-virgin olive oil (EVOO) can be further improved by the addition of olive leaves during olive pressing. However, while Citrus leaves are rich sources of bioactive substances, no data are available in the literature about the effect of Citrus leaf addition on the nutraceutical and sensorial profiles of olive oil. This study aimed at comparing the chemical and sensorial qualities of olive oils obtained from ripe olives pressed together with either Olea or Citrus spp. (lemon or orange) cryomacerated leaves. General composition parameters as well as major antioxidants and antioxidant activity were measured. A panel test evaluation, as well as headspace volatile characterization (headspace solid phase microextraction, HS-SPME), were also performed. All data were compared with an EVOO extracted from the same olive batch used as control. It was possible to obtain Leaf Olive Oils (LOOs) characterized by a higher (p < 0.05) content of antioxidants, compared to the control sample, and the highest oleuropein concentration was detected in the olive oil extracted in presence of olive leaf (+50% in comparison with the control). All the LOOs showed a higher smell complexity and the scent of ripe fruit was generally mitigated. Lemon and olive LOOs showed the best smell profile.

Patè Olive Cake: Possible Exploitation of a By-Product for Food Applications

Patè Olive Cake (POC) is a new by-product derived from recently introduced new decanters in the olive oil production process. POC, is essentially composed of water, olive pulp and olive skin, and is rich in several valuable bioactive compounds. Moreover, it still contains about 8-12% residual olive oil. We characterized the main bioactive compounds in POC from black olives (cv. Leccino and Cellina di Nardò) and also verified the biotechnological aptitude of selected yeast and lactic acid bacteria from different sources, in transforming POC into a new fermented product. The strategy of sequential inoculum of Saccharomyces cerevisiae and Leuconostoc mesenteroides was successful in driving the fermentation process. In fermented POC total levels of phenols were slightly reduced when compared with a non-fermented sample nevertheless the content of the antioxidant hydroxytyrosol showed increased results. The total levels of triterpenic acids, carotenoids, and tocochromanols results were almost unchanged among the samples. Sensory notes were significantly improved after fermentation due to the increase of superior alcohols, esters, and acids. The results reported indicate a possible valorisation of this by-product for the preparation of food products enriched in valuable healthy compounds.

Antennal olfactory responses of adult meadow spittlebug, Philaenus spumarius, to volatile organic compounds (VOCs)

The meadow spittlebug, Philaenus spumarius L. (Hemiptera, Aphrophoridae) is a commonly found vector of Xylella fastidiosa Wells et al. (1987) strain subspecies pauca associated with the "Olive Quick Decline Syndrome" in Italy. To contribute to the knowledge of the adult P. spumarius chemoreceptivity, electroantennographic (EAG) responses of both sexes to 50 volatile organic compounds (VOCs) including aliphatic aldehydes, alcohols, esters, and ketones, terpenoids, and aromatics were recorded. Measurable EAG responses were elicited by all compounds tested. In both sexes, octanal, 2-octanol, 2-decanone, (E)-2-hexenyl acetate, and vanillin elicited the strongest antennal amplitude within the chemical groups of aliphatic saturated aldehydes, aliphatic alcohols, aliphatic acetates and aromatics, respectively. Male and female EAG responses to sulcatol, (±)linalool, and sulcatone were higher than those to other terpenoinds. In both sexes, the weakest antennal stimulants were phenethyl alcohol and 2-pentanone. Sexual differences in the EAG amplitude were found only for four of test compounds suggesting a general similarity between males and females in antennal sensitivity. The olfactory system of both sexes proved to be sensitive to changes in stimulus concentration, carbon chain length, and compound structure. Compounds with short carbon chain length (C5-C6) elicited lower EAG amplitudes than compounds with higher carbon chain length (C9-C10) in all classes of aliphatic hydrocarbons with different functional groups. The elucidation of the sensitivity profile of P. spumarius to a variety of VOCs provides a basis for future identification of behaviorally-active compounds useful for developing semiochemical-based control strategies of this pest.

Molecular and phytochemical analysis of wild type and olive cultivars grown under Saudi Arabian environment

This study aimed to assess genetic variability at molecular and phytochemical levels among the four most commonly grown olive cultivars and the wild-type olive of Saudi Arabia. Sixty-six and 80 amplicons were generated from 9 random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) primers, each, producing an average of 95.9 and 86.44% polymorphism for the two markers, respectively. The PIC values were 82.2% for the RAPD and 85.4% for the ISSR markers and the discrimination power for both the markers was 11.1%. The UPGMA cluster analysis based on the RAPD and ISSR data resulted in the aggregation of cultivars and wild accession with a good bootstrapping value according to their origin. Furthermore, a total of 199 compounds were identified in the cultivars based on peak area, retention time, and molecular formula using GC-MS analyses of methanolic and ethanolic extracts. These compounds were classified according to their chemical class; most of them were fatty acids, alcoholic compounds, carboxylic acids, aldehydes, heterocyclic compounds, ketones, alkanes, and phenols. Genetic and phytochemical distances were significantly correlated, based on the Mantel test. The Saudi wild accession also had high numbers of fatty acids and their esters, and can be used in breeding programs for generating new genotypes with interesting characters.

Comparative Study of Oil Quality and Aroma Profiles from Tunisian Olive Cultivars Growing in Saharian Oasis Using Chemometric Analysis

Aroma profile, oxidative stability and quality parameters of virgin olive oil from four cultivars (Chemlali, Chetoui, Koroneiki and Rjim), grown in Rjim Maatoug oasis in southern of Tunisia, were studied for the first time. The olive oil samples were obtained during maturation from a crop season (2012-2013). The results showed the quality parameters, i.e., free fatty acid, UV absorbance at 232 and 270 nm, increases during maturation exceeding the upper limit established by the IOOC norm. Chlorophyll and carotenoid pigments tended to decrease during ripening stages. The trend of oxidative stability, total phenols and Odiphenols exhibited a reduction of antioxidant activity at more advanced stages of maturity. The marks achieved showed that oil quality degradation is due to the great drought of climate: high temperature, high light intensity and low rainfall. Studied aroma profiles of cultivars were also influenced by severe climatic conditions. Twenty-four compounds were characterized, representing 94.8-99.8% of the total volatiles. In all samples, a strong decrease was observed in aldehydes compounds.

VOCs-Mediated Location of Olive Fly Larvae by the Braconid Parasitoid Psyttalia concolor: A Multivariate Comparison among VOC Bouquets from Three Olive Cultivars

Herbivorous activity induces plant indirect defenses, as the emission of herbivorous-induced plant volatiles (HIPVs), which could be used by parasitoids for host location. Psyttalia concolor is a larval pupal endoparasitoid, attacking a number of tephritid flies including B. oleae. In this research, we investigated the olfactory cues routing host location behavior of P. concolor towards B. oleae larvae infesting three different olive cultivars. VOCs from infested and healthy fruits were identified using GC-MS analyses. In two-choice behavioral assays, P. concolor females preferred infested olive cues, which also evoked ovipositional probing by female wasps. GC-MS analysis showed qualitative and quantitative differences among volatiles emitted by infested and healthy olives. Volatile emissions were peculiar for each cultivar analyzed. Two putative HIPVs were detected in infested fruits, regardless of the cultivar, the monoterpene (E)-β-ocimene, and the sesquiterpene (E-E)-α-farnesene. Our study adds basic knowledge to the behavioral ecology of P. concolor. From an applied point of view, the field application of the above-mentioned VOCs may help to enhance effectiveness of biological control programs and parasitoid mass-rearing techniques.

Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae)

The olive fly, Bactrocera oleae (Rossi), is a monophagous pest that displays an oviposition preference among cultivars of olive (Olea europaea L.). To clarify the oviposition preference, the olive leaf volatiles of three olive cultivars (Cobrançosa, Madural and Verdeal Transmontana) were assessed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) at six different periods of olive fruit maturation and degrees of infestation. A total of 39 volatiles were identified, mainly esters and alcohols, with a minor percentage of aldehydes, ketones and terpenic compounds, including sesquiterpenes. At sampling dates with higher degrees of infestation, cv. Cobrançosa had, simultaneously, significantly lower infestation degrees and higher volatile amounts than the other two cultivars, with a probable deterrent effect for oviposition. The green leaf volatiles (GLVs) (Z)-3-hexen-1-ol and (Z)-3-hexen-1-ol acetate) were the main compounds identified in all cultivars, together with toluene. The abundance of GLVs decreased significantly throughout maturation, without significant differences among cultivars, while toluene showed a general increase and positive correlation with olive fly infestation levels. The results obtained could broaden our understanding of the roles of various types and amounts of olive volatiles in the environment, especially in olive fly host selection and cultivar preference.

Changes in olive oil volatile organic compounds induced by water status and light environment in canopies of Olea europaea L. trees

BACKGROUND

Light and water are major factors in fruit development and quality. In this study, the effect of water and light in Olea europaea trees on volatile organic compounds (VOCs) in olive oil was studied over 2 years. Mature fruits were harvested from three zones of the canopy with different light exposure (64%, 42% and 30% of incident light) of trees subjected to full, deficit or complementary irrigation. VOCs were determined by SPME GC-MS and analysed by principal component analysis followed by discriminant analysis to partition treatment effects.

RESULTS

Fruit fresh weight and mesocarp oil content decreased in zones where intercepted light was less. Low light levels significantly slowed down fruit maturation, whereas conditions of water deficit accelerated the maturation process. The presence of cyclosativene and α-muurulene was associated with water deficit, nonanal, valencene with full irrigation; α-muurulene, (E)-2-hexanal were related to low light conditions, while trans-β-ocimene, α-copaene, (Z)-2-penten-1-ol, hexanal and nonanal to well exposed zones. The year strongly affected the VOC profile of olive oil.

CONCLUSION

This is the first report on qualitative changes in VOCs induced by light environment and/or water status. This information is valuable to better understand the role of environmental factors on the sensory quality of virgin olive oil.

Altered volatile profile associated with precopulatory mate guarding attracts spider mite males

Proximate factors affecting animal behavior include stimuli generated by conspecifics. In spider mites of the genus Tetranychus (Acari: Tetranychidae), males guard pre-reproductive quiescent females, because only the first mating results in fertilization. In a dual-choice experiment, more adult males of T. urticae were attracted to females guarded by a male than to solitary females. Because spider mites are known to perceive volatiles, we hypothesized that guarded and solitary females differ in the volatile blends emitted. To test this hypothesis, headspace volatiles of guarded females, solitary females, and solitary males were collected, respectively. GC/MS analysis detected octanal, methyl salicylate, ethyl 4-ethoxybenzoate, and methyl cis-dihydrojasmonate in all of the groups. Orthogonal Projection to Latent Structures Discriminant Analysis (OPLS-DA) of the blends clearly discriminated guarded females from solitary females, supporting our hypothesis. Individual compounds did not show significant difference in emission rates for guarded females vs. solitary females, suggesting that differences lay in the total blend composition. OPLS-DA did not discriminate between the blends emitted by guarded females and solitary males. In conclusion, the differences in the volatile blends are likely to mediate male discrimination between guarded and solitary females.

Mechanical Strategies to Increase Nutritional and Sensory Quality of Virgin Olive Oil by Modulating the Endogenous Enzyme Activities

 This monograph is a critical review of the biological activities that occur during virgin olive oil (VOO) extraction process. Strategic choices of plant engineering systems and of processing technologies should be made to condition the enzymatic activities, in order to modulate the nutritional and the sensory quality of the product toward the consumer expectations. "Modulation" of the product quality properties has the main aim to predetermine the quantity and the quality of 2 classes of substances: polyphenols and volatile compounds responsible of VOO nutritional and sensory characteristics. In the 1st section, a systematic analysis of the literature has been carried out to investigate the main olive enzymatic activities involved in the complex biotransformation that occurs during the mechanical extraction process. In the 2nd section, a critical and interpretative discussion of the influence of each step of the extraction process on the polyphenols and the volatile compounds has been performed. The effect of the different mechanical devices that are part of the extraction process is analyzed and recommendations, strategies, and possible avenues for future researches are suggested.

Effect of addition of olive leaves before fruits extraction process to some monovarietal Tunisian extra-virgin olive oils using chemometric analysis

The analysis of the effect of cultivar and olive leaves addition before the extraction on the different analytical values revealed significant differences (p < 0.05) in some parameters, mainly in peroxide value, phenols and tocopherol contents, and oxidative stability. Aroma profiles were also influenced by the different varieties and the addition of different amounts (0% and 3%) of olive leaves. Twenty-three compounds were characterized, representing 86.1-99.2% of the total volatiles. Chétoui cultivar has the highest amount of (E)-2-hexenal, followed by Chemlali cultivar, whereas (E)-2-hexen-1-ol was the major constituent of Zalmati and crossbreeding Chemlali by Zalmati cultivars. Sensory analysis showed that Chemlali and Chétoui Zarzis possessed a high fruity, bitter, and pungent taste, whereas the Zalmati and crossbreeding Chemlali by Zalmati had a 'green' taste among its attributes. Indeed, the taste panel found an improvement of the oil quality when an amount of olive leaves (3%) added to the olives fruits.

Valuable nutrients and functional bioactives in different parts of olive (Olea europaea L.)-a review

The Olive tree (Olea europaea L.), a native of the Mediterranean basin and parts of Asia, is now widely cultivated in many other parts of the world for production of olive oil and table olives. Olive is a rich source of valuable nutrients and bioactives of medicinal and therapeutic interest. Olive fruit contains appreciable concentration, 1-3% of fresh pulp weight, of hydrophilic (phenolic acids, phenolic alchohols, flavonoids and secoiridoids) and lipophilic (cresols) phenolic compounds that are known to possess multiple biological activities such as antioxidant, anticarcinogenic, antiinflammatory, antimicrobial, antihypertensive, antidyslipidemic, cardiotonic, laxative, and antiplatelet. Other important compounds present in olive fruit are pectin, organic acids, and pigments. Virgin olive oil (VOO), extracted mechanically from the fruit, is also very popular for its nutritive and health-promoting potential, especially against cardiovascular disorders due to the presence of high levels of monounsaturates and other valuable minor components such as phenolics, phytosterols, tocopherols, carotenoids, chlorophyll and squalene. The cultivar, area of production, harvest time, and the processing techniques employed are some of the factors shown to influence the composition of olive fruit and olive oil. This review focuses comprehensively on the nutrients and high-value bioactives profile as well as medicinal and functional aspects of different parts of olives and its byproducts. Various factors affecting the composition of this food commodity of medicinal value are also discussed.

Ripening attributes of new passion fruit line featuring seasonal non-climacteric behavior

The passion fruit hybrid cultivar 'Passion Dream' (PD) produces two cycles of fruiting per year, in the summer and winter. Self-hybridization of PD created various lines, including 'Ripens during Summer' (RS), which lacks the ability to abscise during winter, suggesting a seasonal nonclimacteric behavior. The two lines were characterized by several quality traits: PD produced high ethylene levels in both seasons; RS produced significantly less ethylene during summer and almost none during winter. The ratio of total soluble solids to titratable acidity (TSS/TA), and aroma volatiles production, as determined by solid-phase microextraction/gas chromatograph-mass spectrometer (SPME/GC-MS) techniques, and taste indices were highest in PD summer fruits and lowest in RS winter fruits. Peel color in PD was affected by environmental and storage temperatures, whereas RS fruits always showed a strong purple color. The present findings suggest that ethylene production levels in passion fruit greatly influence various ripening processes, including acid degradation, increased TSS/TA ratio, accumulation of aroma volatiles, and tastiness.

Determination of the volatile profile of stoned table olives from different varieties by using HS-SPME and GC/IT-MS

BACKGROUND

The volatile composition of alcaparras stoned table olives produced from five of the most representative olive cultivars (cv. Cobrançosa, Madural, Negrinha de Freixo, Santulhana and Verdeal Transmontana) from the Trás-os-Montes region (north-east of Portugal) was analytically characterised using headspace-solid phase microextraction/gas chromatography-ion trap-mass spectrometry.

RESULTS

Overall, 42 volatile compounds were identified, belonging to distinct chemical classes: 15 aldehydes, seven esters, five alcohols, five sesquiterpenes, four norisoprenoids derivates, three monoterpenes, o ne ketone and two alkenes. Aldehydes were the major chemical class identified in all olive cultivars studied (more than 74% of all the volatile compounds identified). Hexanal, phenylacetaldehyde and (E,E)-2,4-heptadienal were the major volatile compounds identified.

CONCLUSIONS

It was possible to discriminate the results obtained from the volatile profile of the five olive cultivars by using principal component analysis. Both qualitative and quantitative fractions of alcaparras table olives were influenced by olive cultivar, which confers a single aroma. This fact certainly influences consumer preference and acceptability towards a specific olive cultivar.

Oleuropein in olive and its pharmacological effects

Olive from Olea europaea is native to the Mediterranean region and, both the oil and the fruit are some of the main components of the Mediterranean diet. The main active constituents of olive oil include oleic acid, phenolic constituents, and squalene. The main phenolic compounds, hydroxytyrosol and oleuropein, give extra-virgin olive oil its bitter, pungent taste. The present review focuses on recent works that have analyzed the relationship between the major phenolic compound oleuropein and its pharmacological activities including antioxidant, anti-inflammatory, anti-atherogenic, anti-cancer activities, antimicrobial activity, antiviral activity, hypolipidemic and hypoglycemic effect.

Comparative study on volatile compounds from Tunisian and Sicilian monovarietal virgin olive oils

The effects of ripening degree of olives on volatile profile of monovarietal virgin olive oils (VOO) from Tunisian and Sicilian cultivars were investigated. Fruits obtained from Tunisia (Chétoui and Chemlali) and Italy (Nocellara del Belice, Biancolilla and Cerasuola) were picked at three different stages of ripeness and then immediately processed. Moreover, the changes in volatile composition were evaluated in Chétoui variety as a function of the irrigation regime versus the rain-fed control. Using headspace-solid-phase microextraction (HS-SPME) technique coupled to GC-MS and GC-FID, the volatile compounds of the monovarietal virgin olive oils were identified and quantitatively analyzed. The proportions of different classes of volatiles of oils showed significant differences throughout the maturity process. The results suggest that adding to the genetic factor; agronomic conditions affect the volatile formation and therefore the organoleptic properties of VOO.

Characterization of terpenoid volatiles from cultivars of eastern hemlock (Tsuga canadensis)

The volatile terpenoid fraction from needles in 13 cultivars of Tsuga canadensis L. (Carriere) was analyzed by gas chromatography with mass spectrometry (GC-MS). The results of this study are considered along with previously reported results for foliar terpenoid levels of the Asian (T. sieboldii, T. chinensis, T. diversifolia), western North American (T. mertensiana, T. heterophylla), and eastern North American species (T. canadensis, T. caroliniana) of hemlock to draw conclusions about the potential of cultivar host resistance to the hemlock woolly adelgid (Adelges tsugae Annand). It is suggested that hemlocks in eastern North America have adapted their terpenoid chemistry for protection against endemic defoliators and that this has made them vulnerable to non-native, sucking pests such as adelgids and scales. Some cultivars of T. canadensis have a terpenoid profile that resembles that of the resistant noneastern North American species and are candidates for biological screening for resistance. Among the cultivars, the variation in terpenoid chemistry did not absolutely correspond with the considerable differences in morphological characters observed, indicating that the terpenoid chemistry is not definitively coupled with hemlock morphology.

A metabolomic approach to the evaluation of the origin of extra virgin olive oil: a convenient statistical treatment of mass spectrometric analytical data

The selection of suitable markers from the secondary metabolism of lipoxygenase, in experimental olive oils produced from drupes harvested in different areas of the Italian Calabria region and of Tunisia, allows an easy discrimination between each cluster of samples. The origin of the foodstuff can be ascertained even when the distances between the production zones are very close to each other as in Calabria. Olive oils produced from irrigated and nonirrigated farms in Tunisia were also clearly distinguishable. The markers were detected by chemical ionization mass spectrometry with an ion trap gas chromatography-mass spectrometry apparatus. The quantitative data of Calabrian olive oil samples were subjected to linear discriminant analysis, whereas the Tunisian data were treated by means of other two statistical tools, i.e., the Kruskal-Wallis test and the Wald-Wolfowitz test.

Discrimination of olive oils and fruits into cultivars and maturity stages based on phenolic and volatile compounds

Olive oil and fruit samples from six cultivars sampled at four different maturity stages were discriminated into cultivars and maturity stages. The variables-volatile and phenolic compounds-that significantly (p < 0.01) discriminated cultivars and maturity stage groups were identified. Separation by stepwise linear discriminant analysis revealed that Manzanilla olive cultivar was separated from cultivars Leccino, Barnea, Mission, Corregiola, and Paragon, whereas cultivars Corregiola and Paragon formed a cluster. The volatile compounds hexanol, hexanal, and 1-penten-3-ol were responsible for the discrimination of cultivars. All maturity stages were discriminated, with the separation of early stages attributed to oil phenolic compounds, tyrosol and oleuropein derivatives, whereas the volatile compounds (E)-2-hexenal, hexanol, 1-penten-3-ol, and (Z)-2-penten-3-ol characterized the separation of all maturity stages and in particular the late stages. Hexanol and 1-penten-3-ol characterized the separation of both cultivars and maturity stages.

Preliminary assay on the radical scavenging activity of olive wood extracts

The dichloromethane and ethanol extracts of Olea europaea wood (picual olive cultivar) were screened for antioxidant activity, determined by the DPPH free radical scavenging assay. The ethanol extract displayed potent antioxidant activity.

Screening for key odorants in Moroccan green olives by gas chromatography-olfactometry/aroma extract dilution analysis

"Spanish style" Moroccan green table olives were screened for potent odorants by gas chromatography-olfactometry/aroma extraction dilution analysis of a representative Likens-Nickerson extract. (Z)-3-Hexenal [flavor dilution factor (FD) = 256], (E,E)-2,4-decadienal (FD = 128), and (E,Z)-2,4-decadienal (FD = 64) were revealed to confer green and coriander/paraffin oil odors to both fruit and oil extracts, whereas guaiacol (FD = 128) imparted a bad olive, phenolic note. Methional (3-methylthiopropionaldehyde, FD = 128) and several terpenes (FD </= 64) such as alpha-farnesene, trans-nerolidol, nerol acetate, limonene, alpha-, beta-, and gamma-terpineol, linalool, and beta-myrcene were detected in the fruit extract, although they were not reported as olive oil constituents.

Volatile fractions from three cultivars of Olea europaea L. collected in two different seasons

The chemical composition of the volatile fractions from leaves of three Olea europaea L. cultivars (Leccino, Frantoio, and Cipressino) harvested at two different times of the year were examined by GC and GC-MS. The results showed a high content of aliphatic aldehydes in the three cultivars during both harvesting periods and an increase of (E)-2-hexenal (an aldehyde with high antimicrobial properties) percentage from July to November.

Volatiles from leaves, fruits, and virgin oil from Olea europaea Cv. Olivastra Seggianese from Italy

The volatiles produced by leaves and fruits of Olea europaea cv. Olivastra Seggianese have been analyzed in two different phenological stages. Furthermore, the volatiles of the virgin olive oil obtained from ripe fruits has been characterized. The volatiles were sampled by means of two different techniques: hydrodistillation and SPME. Differences were observed between the two different collection times, the different organs, and sampling techniques. The major constituents were often aldehydes, particularly (E)-2-hexenal (9.8-48.0%); however, also many terpenoids have been identified, mainly (E,E)-alpha-farnesene (0.2-27.0%), linalool (0-3.6%), beta-caryophyllene (0-8.1%), and valencene (0-2.5%). This is the first investigation on this cultivar.