2,001 research outputs found
Olfactory responses to volatile organic compounds and movement parameters of Philaenus spumarius and Cicadella viridis
Xylella fastidiosa, the causal agent of several diseases in crops of economic interest,
could be rapidly transmitted and spread throughout the agroecosystem landscape by
xylem sap-feeding
insects. Chemical signals in the environment drive the behaviour
of insects. Attractive or repulsive responses to signals may affect insects’ fitness, survival
and reproduction, and elicit different movement patterns. Specific movement
patterns derived from olfactory cues towards the selection of plants for feeding may
trigger the transmission of the pathogen by the insect. Thus, understanding vectors’
olfactory response and movement parameters are of utmost importance. This work
aimed to assess the olfactory response of Philaenus spumarius and Cicadella viridis
adults to two Volatile Organic Compounds (VOCs) (cis-3-
hexenyl
acetate and cis-3-
hexen-
1-
ol)
present in almond, olive and vine leaves. Insects’ behavioural responses
were conducted in a four-arm
olfactometer, and the two aforementioned VOCs were
tested at different concentrations (5, 10, 20 and 30 μg/μl). At the lowest concentration,
females of P. spumarius were significantly attracted by the two VOCs. At the
highest concentrations, no significant differences were detected among treatments.
Cicadella viridis individuals showed no significant differences in their choice at any
concentration. Additionally, the walking movement of these insects was also studied
in the absence of food. Females of P. spumarius and C. viridis can walk significantly
more at a significantly higher velocity than males. Knowledge of the olfactory response
of X. fastidiosa vectors and their movement parameters can be essential to
develop new tools to limit the spread of this phytopathogen.Fundação para a Ciência e a Tecnologia,
Grant/Award Number: (LA/P/0007/2020, 2020.07051.BD and UIDB/00690/2020; Horizon 2020 Framework Programme, Grant/Award Number: Grant Agreement 727987info:eu-repo/semantics/publishedVersio
Avaliação sensorial de infusões com diferentes misturas de Lippia alba e Syzygium aromaticum
Na atualidade, existe uma tendência crescente para o consumo de
infusões preparadas a partir de diferentes matérias-primas, sendo a mistura
de elas uma opção frequente. Contudo, para proporcionar uma maior
satisfação a quem as ingere, as quantidades e proporções das misturas deve
previamente ser estudada do ponto de vista sensorial. Assim, o presente
trabalho teve como principal objetivo proceder à avaliação sensorial infusões
obtidas a partir de diferentes misturas de lipia (Lippia albaj e de cravo
(Syzygium aromaticum) nomeadamente: Infusão l (li): 25% de cravo e 75%
de lipia; Infusão Zfl;): 50% de cravo e 50% de lipia; Infusão 3 (la): 75% de cravo
e 25% de lipia; Infusão 4 (14): 100% de cravo; e Infusão 5 (Is): 100% de lipia,
para verificar a que apresenta maior aceitação. As infusões foram preparadas
à razão de lOg de mistura de plantas/L de água, com água a 80^C e deixadas a
repousar durante 5 minutos. Posteriormente foram sujeitas à avaliação
sensorial por um painel de doze provadores previamente treinado e que
avaliou os seguintes aspetos: intensidade de cor, transparência, sensação do
aroma, intensidade do aroma, sensação bucal, persistência, amargar,
adstringência, doce o picante, numa escala não estruturada de O a 10. De
acordo com os resultados obtidos, verificou-se que a intensidade de cor
variou de 0,7 e 4,3 com os valores superiores a serem registados em lie l;. A
transparência, com valores a oscilar entre 0,8 e 2,7 sendo mais elevada em l;.
A 13 foi a que apresentou um aroma mais agradável comparativamente às
restantes infusões com uma mediana de 7, 1, em oposição a Is foi a infusão
considerada menos agradável de todas as testadas pelo painel. Na avaliação
da intensidade de aroma, a [4 foi a que apresentou maior intensidade de
aroma com valores médios de 7e a Isa que apresentou menores valores de
intensidade de aroma com 4 de mediana. As l; e [3 apresentaram uma
sensação bucal mais agradável, eas lie Iz a maior persistência. Na sensação de amargo, as l; e [4 foram as consideradas mais amargas e adstringentes. No
que respeita ao doce, a maior intensidade foi detetada em l; e Ig, enquanto a
menor correspondeu à 14. No picante, a [4 foi a que apresentou a maior
intensidade de picante foi apresentada pela [4 e a menor pela \s. Os aromas
sensoriais predominantemente referidos foram o herbal com sensação
eucalipto, menta, pinho e erva cortada; aromas doces a mel néctar e aromas
cítricos a limão, o que estará relacionado com a composição química dos
óleos essenciais das plantas em mistura, como por exemplo o teor em
eugenol do cravo que origina sensações de adocicado e o cravacol da lipia
como adstringente. De uma maneira geral, a mistura que continha 50% de
lipia e 50% de cravo (l;) foi a preferida pelo painel.info:eu-repo/semantics/publishedVersio
Physico-chemical and sensory characteristics of jellies made from seven grapevine (Vitis vinifera L.) varieties
Jellies of seven grapevine varieties were physico-chemical and sensorial characterized for the first time. Jellies differed significantly in moisture and ash contents, colour, pH, acidity and antioxidant activities. 'Tinta Carvalha' was the darkest and redness jelly, showing the highest antioxidant activity. Regarding sensory characteristics, no significant differences in the appearance, taste, sweetness, acidity and global assessment were observed among jellies. Nevertheless, these attributes were positively evaluated. In conclusion, the production of different jellies will allow the valorisation of grapevine varieties with less potential for wine production, helping to preserve biodiversity, and be an economic alternative to grape producers who may elaborate an enjoyable product with interesting bioactivity.Authors are grateful to POCTEP - Programa de
Cooperação Transfronteiriça Espanha - Portugal
for financial support (Project “RED/AGROTEC – Experimentation network and transfer for development of agricultural and agro industrial
sectors between Spain and Portugal).info:eu-repo/semantics/publishedVersio
The surrounding landscape shapes the abundance of Sphaerophoria scripta and Melanostoma mellinum (Diptera: Syrphidae) in Portuguese vineyards
1. The intensification of urban and agricultural use in the landscape is the major driver of biodiversity loss and the consequent decrease of ecosystem services provided by insects. Syrphids are important ecosystem service providers, including pest regulation, pollination, and matter decomposition.
2. Understanding how the surrounding landscape to crops affects syrphids is essential to implementing strategies to reverse the negative effects of the agricultural landscape’s simplification.
3. This study describes the Syrphidae community in Portuguese vineyards and the response of the most abundant species, Sphaerophoria scripta Linnaeus, 1758, and Melanostoma mellinum Linnaeus, 1758, to the landscape composition and configuration within a gradient of distances (500, 1000, and 2000 m) from the sampled vineyards.
4. The presence of seminatural habitats and other crops in the surrounding landscape increased both species at the largest distance, whereas the presence of artificial territory, olive orchards, and vineyards reduce M. mellinum at some of the buffers.
5. Increasing seminatural habitats in the vineyards surrounding landscape (2000 m) and, potentially, introducing nature-friendly practices in the principal crops around vineyards may favour syrphid abundance.The authors are grateful to the Foundation for Science and Technology
(FCT, Portugal) for financial support by national funds FCT/MCTES
(PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020), and
to the Associate Laboratory SusTEC (LA/P/0007/2020); Isabel Rodrigues
acknowledges the PhD grant (2020.07051.BD) provided by FCT.info:eu-repo/semantics/publishedVersio
Characterisation of olive oils from the Douro Valley, Portugal: study of the volatile fraction and its relationship with sensory characteristics
In recent years, the demand for olive oils from the Douro region (Portugal) has increased in line with wine. Thus, it is essential to characterise these olive oils to evaluate them. Therefore, this work describes the sensory and volatile profiles of olive oils produced in the Douro region. These were mainly identified as ripe fruity. Among the olfactory and gustatory sensations, the attributes of dried fruits, tomato, apple, tomato leaves, banana, and lavender stood out. Regarding volatile compounds, the following were detected in all samples: (E)-2-hexenal, (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol acetate, 1-hexanol, and 2-methyl-4-pentanal. Moreover, it was impossible to separate the olive oils by sub-regions. In conclusion, studying the volatile fraction and their relationship with sensory attributes are essential to guarantee the genuineness and identity of these olive oils with a view to their future appreciation.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal),
which gave financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021). The authors are also grateful to the Project OLIVECOA—Centenarian olive trees of Côa Valley region: rediscovering the past to valorize the future, ref. COA/BRB/0035/2019 and the GreenHealth Project (NORTE-01-0145-FEDER-
000042) co-financed by European Regional Development Fund (ERDF) through the NORTE 2020 (Programa
Operacional Regional do Norte 2014/2020). Nuno Rodrigues thanks to National funding by
FCT—Foundation for Science and Technology, P.I., through the institutional scientific employment
program contract.info:eu-repo/semantics/publishedVersio
Tire Rubber-cement Composites: Effect Of Slag On Properties [compósites De Cimento - Borracha De Pneus: Efeito Da Escória Nas Propriedades]
Tire rubber-cement composites prepared with type I and three slag-modified cements were studied. Flexural strength, water sorption and resistance to acid attack of specimens were investigated. A decrease in modulus of rupture (MOR) is observed for all specimens containing rubber, when compared with specimens without rubber (controls). The MOR increases with the increase of the hydraulic activity of the slag upon undistinguishable from specimens prepared with type I cement. This behavior is observed for all slag-cements pastes and for mortars control specimens. For mortar specimens with rubber the MOR is independent of the cement type used. A reduction in water sorption is observed for control and with-rubber mortar specimens prepared with all slag-cements, when compared to type I cement. For mortar specimens with rubber, the lower the basicity of the slag, the lesser the water sorption of the composites. These results denote lower porosity and consequently better rubber-matrix adhesion for these specimens. Also, a smaller rate of water sorption is observed for specimens with rubber, particularly for specimens prepared with the less basic slag cements, when comparing with the controls. Results of acid attack to the slag modified mortars indicate that specimen susceptibility is governed not only by microstructural aspects, like porosity and permeability, but also by chemical aspects as the difference in alkali content or the amount of unreacted slag in the specimens.52324283292Lee, B.I., Burnett, L., Miller, T., Postage, P., Cuneo, J., (1993) J. Mater. Sci. Lett, 12, p. 967I. B. Topçu, Gem. Conor. Res. 25 (1995) 304Raghavan, D., Huynh, H., Ferraris, C.F., (1998) J. Mater. Sci, 33, p. 1745Bignozzi, M.C., Saccani, A., Sandrolini, F., (2000) Composites A, 31, p. 97Raghavan, D., (2000) J. Appl. Polym. Sci, 77, p. 934M. Nehdi, A. Khan, Cem. Concr. Aggregates 23 (2001) 3Hernandez-Olivares, F., Barluenga, G., Bollati, M., Witoszek, B., (2002) Cem. Concr. Res, 32, p. 1587N. Segre, I. Joekes, Gem. Concr. Res. 30 (2000) 1421(2001) Lea's Chemistry of Cement and Concrete, , P. C. Hewlett Ed, 4 th Ed, Butterworth Heinemann, OxfordMyers, D., (1999) Surfaces, Interfaces, and Colloids-Principles and Applications, , 2nd Ed, John Wiley & Sons, New YorkBikerman, J.J., (1961) The Science of Adhesive Joints, , Academic Press, New YorkMindess, S., Interfaces in concrete (1989) Materials Science of Concrete I, p. 163. , J.P. Skalny Ed, The Am. Ceram. Soc, Westerville, OHLuke, K., Glasser, F.P., (1987) Cem. Concr. Res, 17, p. 273M. A. Cincotto, A. F. Battagin, V. Agopyan, Bulletin 65, Ed.: Institute for Technological Research, IPT, S. Paulo, Brazil (1992)ASTM C150 - Standard specification for Portland cement, American Society for Testing and Materials (1995)- Standard specification for blended hydraulic cements (1994), ASTM C595, American Society for Testing and MaterialsMindess, S., Young, J.F., (1981) Concrete, , Prentice-Hall, Englewood Cliffs, New JerseyMehta, P.K., Monteiro, P.J.M., (1993) Concrete: Structure, Properties and Materials, , 2nd Ed, Prentice-Hall, Englewood Cliffs, New JerseyGriffith, A.A., (1920) Phil. Trans. R. Soc. Lond. A, 221, p. 163Birchall, J.D., Howard, A.J., Kendall, K., (1981) Nature, 289, p. 388Martins, M.A., Mattoso, L.H.C., (2004) J. Appl. Polym. Sci, 91, p. 670Lumley, J.S., Gollop, R.S., Moir, G.K., Taylor, H.F.W., (1996) Cem. Concr. Res, 26, p. 139Glasser, F.P., Chemical, mineralogical, and microstructural changes occurring in hydrates slag-cement blends (1991) Materials Science of Concrete II, p. 41. , J. P. Skalny, S. Mindess Eds, The Am. Ceram. Soc, Westerville, OHSegre, N., Monteiro, P.J.M., Sposito, G., (2002) J. Colloid Interface Sci, 248, p. 521Falcon, P., Adenot, F., Jacquinot, J.F., Petit, J.C., Cabrillac, R., Jordas, M., (1998) Cem. Conor. Res, 28, p. 847Israel, D., Macphee, D.E., Lachowski, E.E., (1997) J. Mater. Sci, 32, p. 4109Chandra, S., (1988) Cem. Conor. Res, 18, p. 193Zivica, V., Bajza, A., (2001) Constr. Build. Mater, 15, p. 331Pavlik, V., (1994) Cem. Conor. Res, 24, pp. 551-562Debelie, N., Verselder, H.J., Deblaere, B., Vannieuwenburg, D., Verschoore, R., (1996) Cem. Conor. Res, 26, p. 1717Shi, C., Stegemann, J.A., (2000) Cem. Conor. Res, 30, p. 803Zivica, V., Bajza, A., (2002) Constr. Build. Mater, 16, p. 215Deceukelaire, L., (1992) Cem. Conor. Res, 22, p. 903A. Macias, S. Goni, J. Madrid, Cem. Conor. Res. 29 (1999) 2005J. Hill, E. A. Byars, J. H. Sharp, C. J. Lynsdale, J. C. Cripps, Q. Zhou, Cem. Conor. Compos. 25 (2003) 997Hobbs, D.W., (2001) Int. Mater. Rev, 46, p. 11
Biocontrol ability and production of volatile organic compounds as a potential mechanism of action of olive endophytes against Colletotrichum acutatum
Olive anthracnose, mainly caused by Colletotrichum acutatum, is considered a key biotic
constraint of the olive crop worldwide. This work aimed to evaluate the ability of the endophytes
Aureobasidium pullulans and Sarocladium summerbellii isolated from olive trees to reduce C. acutatum
growth and anthracnose symptoms, and to assess A. pullulans-mediated changes in olive fruit
volatile organic compounds (VOCs) and their consequences on anthracnose development. Among
the endophytes tested, only A. pullulans significantly reduced the incidence (up to 10-fold) and
severity (up to 35-fold) of anthracnose in detached fruits, as well as the growth (up to 1.3-fold),
sporulation (up to 5.9-fold) and germination (up to 3.5-fold) of C. acutatum in dual culture assays.
Gas chromatography–mass spectrometry analysis of olives inoculated with A. pullulans + C. acutatum
and controls (olives inoculated with C. acutatum, A. pullulans or Tween) led to the identification
of 37 VOCs, with alcohols being the most diversified and abundant class. The volatile profile
of A. pullulans + C. acutatum revealed qualitative and quantitative differences from the controls
and varied over the time course of microbial interactions. The most significant differences among
treatments were observed at a maximal reduction in anthracnose development. At this stage, a set of
VOCs, particularly Z-3-hexen-1-ol, benzyl alcohol and nonanal, were highly positively correlated
with the A. pullulans + C. acutatum treatment, suggesting they play a critical role in anthracnose
reduction. 6-Methyl-5-hepten-2-one and 2-nonanone were positively associated with the C. acutatum
treatment and thus likely have a role in pathogen infection.This research was funded by FEDER funds through COMPETE (Operational Programme
for Competitiveness Factors) and by the Foundation for Science and Technology (FCT, Portugal)
within the POCI-01-0145-FEDER-031133 (MicOlives, PTDC/ASP-PLA/31133/2017) project, as well
as the Mountain Research Center—CIMO (UIDB/00690/2020).info:eu-repo/semantics/publishedVersio
Impact of frost on the morphology and chemical composition of cv. Santulhana olives
Frost events and extreme weather phenomena greatly affect several characteristics of the
olive fruit. This study evaluated the impact of frost on the morphology, composition (moisture,
fat, fatty acids, tocopherols, and total phenolic contents), and antioxidant activity of olives of cv.
Santulhana. A total of 14 trees from the same geographical region (Santulhão, northeast of Portugal)
were chosen, including trees subjected or not subjected to frost conditions (n = 7 each). The results
showed that frost led to morphological changes in olive fruits, particularly in terms of weight and
diameter, which were imposed by a huge decrease in the moisture content (-20%). Fat relative
content increased as a consequence of the water loss (+29% in fresh pulp weight), with a slight
reduction of the relative abundance of saturated fatty acids (-4%) and tocopherol contents in the
fat (-17%). However, the total phenolic contents and antioxidant activity were severely affected
(-70% and -42%, respectively), with potential consequences for the olive oil stability and sensorial
attributes. Principal component analysis showed that both morphological and chemical parameters
could be used as biomarkers to identify olives subjected or not subjected to frost. The overall negative
impact of frost on the minor antioxidant contents of cv. Santulhana olives may anticipate a quality
loss of olive oils extracted from olives affected by frost.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for
financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to REQUIMTELAQV
(UIDB/50006/2020) units and to the Associate Laboratories for Green Chemistry-LAQV
(UIDB/50006/2020) and SusTEC (LA/P/0007/2020). Nuno Rodrigues thanks to National funding
by FCT—Foundation for Science and Technology, P.I., through the institutional scientific employment
program-contract. Ana I. Rodrigues thanks the financial support by OleaChain project “Skills for
sustainability and innovation in the value chain of traditional olive groves in the Northern Interior of
Portugal” (NORTE-06-3559-FSE-000188).info:eu-repo/semantics/publishedVersio
Olive oil sensory analysis as a tool to preserve and valorize the heritage of centenarian olive trees
In inland areas of Portugal and some regions of the Mediterranean basin, olive production
is based on traditional olive groves, with low intensification, local cultivars, aged plants, and centenarian
trees. These plants play a key role in the ecosystem, contributing to carbon sequestration and
possessing a high genetic diversity, particularly important for selecting cultivars more resistant to
climatic changes. Appreciation of the value of this genetic diversity implies genetic, morphological,
and physicochemical characterization of centenarian trees, which is expensive and time-consuming.
Sensory evaluation is also of utmost importance. Thus, in this study, centenarian olive trees were
selected in the Côa Valley region, a UNESCO World Heritage site. The descriptive sensory profile of
their extracted olive oils was established and used to cluster the oils, using hierarchical clustering
analysis, and consequently the olive trees, into five groups with similar intensities of perceived
olfactory–gustatory attributes. Each cluster revealed olive oils with unique sensory patterns, presumably
due to similarities of the olive trees, confirming the potential of the proposed screening
approach. The identification of sensorially homogeneous oil-tree groups would reduce the number of
specimens needed for subsequent morphological, genetic, and chemical characterization, allowing a
cost-effective and robust future evaluation procedure.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support from national funds FCT/MCTES to CIMO (UIDB/00690/2020) and SusTEC (LA/P/0007/2020). This work was also supported by the FCT project OLIVECOA-Centenarian olive trees of Coa Valley region: rediscovering the past to valorize the future, ref. COA/BRB/0035/2019. Nuno Rodrigues was funded by FCT-Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio
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