Autochthonous Croatian grapevine cultivar 'Jarbola' – molecular, morphological and oenological characterization

Research Note

Važnost tla za rast bijelog tartufa (Tuber magnatum) u motovunskoj šumi, Istra

The mixed oak forest located near the town of Motovun is a well-known white truffle (Tuber magnatum Pico) producing area of the Istria region. Motovun Forest covers a 900-ha area in the fluvial plain of the Mirna River, which flows into the Adriatic Sea through a hilly landscape originating in a sedimentary sequence of a Triassic-Eocene carbonatic platform and Eocene-Oligocene Flysch turbidites. T. magnatum production has been decreasing in the last 10 years and a study was specifically performed in an attempt to explain this. Productive soils of the valley bottom were compared with unproductive soils on the slopes, the latter being drier, thinner and more developed than the former. T. magnatum carpophores are not found all over the fluvial plain and Motovun Forest was further subdivided into productive, unproductive and occasionally productive areas. All soils of the valley bottom were thick and continuously rejuvenated by the frequent arrival of fine sediments from slopes, but only unproductive ones were characterized by water saturation in some periods of the year. The soil comparison proved the need of T. magnatum for an alkaline, moist, very well drained and aerated soil environment. Moreover, soils suitable for T. magnatum should be neither too dry nor too moist. In Motovun Forest, the decrease in production has been taking place in conjunction with public works that have modified the hydraulic equilibrium of the area causing an overall drying of the forest soil.Miješana motovunska hrastova šuma jedno je od najznačajnijih područja za sakupljanje bijelog tartufa (Tuber magnatum Pico) u Istri. Motovunska šuma pokriva područje od 900 ha u dolini rijeke Mirne, koja utiče u Jadransko more prolazeći kroz brežuljkasti pejzaž stvoren sedimentacijskim procesima na trijas-eocenskoj vapnenačkoj podlozi i eocen-oligocenskim fliš procesima. Bijeli tartuf pronalazi se samo u nizinskom dijelu doline, a pronađene količine u zadnjih nekoliko godina opadaju. Istraživanje je obavljeno s ciljem da se utvrde karakteristike tla u području Motovuna pogodnog za rast tartufa, i da se pokuša objasniti uzrok pada u njihovoj proizvodnji. Karpofore bijelog tartufa ne pronalaze se u cijelom riječnom području, zato je motovunska šuma podijeljena u produktivna, neproduktivna i povremeno produktivna područja. Produktivna područja u donjem dijelu šume uspoređena su s manje vlažnim, tanjim i bolje razvijenim neproduktivnim područjima na padinama. Sva tla u nizinskom dijelu doline su debela i slabo razvijena zahvaljujući stalnom spuštanju finog sedimenta s padina, ali su samo neproduktivna područja karakterizirana vodenim zasićenjem u nekim periodima u godini. Usporedba tala dokazala je potrebu bijelog tartufa za vlažnim, dobro dreniranim i lužnatim tlom, uz specifične zahtjeve za dobrim prozračivanjem i rahlošću. Tlo pogodno za rast bijelog tartufa ne smije biti previše suho, ni previše vlažno. Smatramo da je u motovunskoj šumi došlo do pada proizvodnje bijelog tartufa zbog niza javnih radova koji su promijenili vodni režim područja uzrokujući sušenje šumskog tla

Comparison of pyrethrins extraction methods efficiencies

Extraction efficiency of insecticidal active compounds from dried Dalmatian pyrethrum flowers (Chrysanthemum cinerariaefolium /Trevir/Vis) was tested using different techniques and solvents. The research included six treatments which are the combination of two techniques (soxtec and ultrasound) and three different solvents (hexane, ethanol and petroleum ether). Dalmatian pyrethrum is a perennial herb native to Croatia. Its powder prepared from dried flower heads has been used as naturalinsecticide for centuries in traditional Croatian farming systems. It has no toxicity to man and animals but possesses ecological benefits that have led to increasing worldwide production of this natural insecticide. Nowadays, it is cultivated mainly at higher altitudes in tropical countries such as Kenya, Tanzania and Rwanda. The present investigation was directed in identifying a simple and reliable extraction treatment using solvents with lower cost and toxicity and an adequate method for the identification and separation of active compounds (pyrethrins) with possible application in enterprises or industry. Best developed method was used for determination of pyrethrin content in three different natural populations of Chrysanthemum. The results revealed high content of total pyrethrins inpopulations grown in Croatia. Developed method and good quality product give a possibility for this culture to become again an exporting and economically valid product for Croatia

Influencia de la temperatura de almacenamiento sobre los parámetros de calidad, fenoles y compuestos volátiles de aceites de oliva vírgenes croatas

The influence of low storage temperature (+4 °C and －20 °C) and conventional storage room temperature on the quality parameters, phenolic contents and volatile profiles of Buža, Črna and Rosinjola monovarietal virgin olive oils after 12 months of storage was investigated in this study. Virgin olive oils stored at low temperatures maintained better quality parameters than oils stored at room temperature. A negligible decrease in the total phenols was detected after 12 months of storage at all investigated temperatures. The total volatile compounds, aldehydes, alcohols and esters in almost all stored samples were unchanged compared to fresh oils. Total ketones increased after storage, although at a lower temperature these changes were less notable. An increase in the oxidation indicators hexanal and hexanal/E-2-hexenal ratio was the lowest in oils stored at +4 °C.Storage at temperatures lower than room temperature could help to prolong the shelf-life of extra virgin olive oil by maintaining high quality parameters and preserving the fresh oil’s volatile profile.Se ha estudiado la influencia, durante 12 meses, de temperaturas bajas (+4 °C y −20 °C) y convencional (ambiente), sobre los parámetros de calidad, contenido fenólico y perfil de volátiles de aceites de oliva vírgenes monovarietales Buža, Črna y Rosinjola. Los aceites de oliva vírgenes almacenados a bajas temperaturas mantienen mejores propiedades de calidad que los aceites almacenados a temperatura ambiente. Se encontró una disminución no significativa de los fenoles totales después de 12 meses de almacenamiento a todas las temperaturas estudiadas. Los compuestos volátiles totales, aldehídos, alcoholes y ésteres, en casi todas las muestras almacenadas, se mantuvieron sin cambios en comparación con los aceites frescos. Las cetonas totales incrementaron tras el almacenamiento, aunque a temperaturasmas bajas estos cambios fueron menos notables. El incremento de los indicadores de la oxidación hexanal y la relación hexanal/E-2-hexenal fue más bajo en los aceites almacenados a +4 °C. El almacenamiento a temperaturas inferiores a la temperatura ambiente ayuda a prolongar la vida útil de los aceites de oliva virgen extra, manteniendo la alta calidad y preservando el perfil de volátilesde un aceite fresco

Citizen science versus professional data collection: Comparison of approaches to mosquito monitoring in Germany

Due to the recent emergence of invasive mosquito species and the outbreaks of mosquito-borne diseases in Europe, research on the ecology and diversity of the mosquito fauna has returned to scientific agendas. Through a nationwide surveillance programme in Germany, mosquitoes have been monitored actively by systematically operated traps since 2011, and passively by the 'Mückenatlas' (mosquito atlas) citizen science project launched in 2012. To assess the performance of both monitoring methods we compared the two respective datasets with regard to habitat coverage, species composition and the ability to detect invasive mosquitoes. The datasets include observations from the beginning of the project until the end of 2017. We found significant differences in species composition caused by land use types and the participants' recording activity. Active monitoring performed better in mapping mosquito diversity, whereas passive monitoring better detected invasive species, thereby using data from private premises scientists usually cannot access. Synthesis and applications. Active and passive monitoring is complementary. Combining them allows for the determination of mosquito diversity, efficient detection of emerging invasive species and the initiation of rapid-response actions against such invaders. The 'Mückenatlas' sets an example for the usefulness of citizen science when included in a national monitoring programme, an approach that may be worth copying for tackling the global spread of arthropod vectors of disease agents

Influence of storage temperature on quality parameters, phenols and volatile compounds of Croatian virgin olive oils

The influence of low storage temperature (+4 °C and －20 °C) and conventional storage room temperature on the quality parameters, phenolic contents and volatile profiles of Buža, Črna and Rosinjola monovarietal virgin olive oils after 12 months of storage was investigated in this study. Virgin olive oils stored at low temperatures maintained better quality parameters than oils stored at room temperature. A negligible decrease in the total phenols was detected after 12 months of storage at all investigated temperatures. The total volatile compounds, aldehydes, alcohols and esters in almost all stored samples were unchanged compared to fresh oils. Total ketones increased after storage, although at a lower temperature these changes were less notable. An increase in the oxidation indicators hexanal and hexanal/<em>E</em>-2-hexenal ratio was the lowest in oils stored at +4 °C.Storage at temperatures lower than room temperature could help to prolong the shelf-life of extra virgin olive oil by maintaining high quality parameters and preserving the fresh oil’s volatile profile.<br><br>Se ha estudiado la influencia, durante 12 meses, de temperaturas bajas (+4 °C y −20 °C) y convencional (ambiente), sobre los parámetros de calidad, contenido fenólico y perfil de volátiles de aceites de oliva vírgenes monovarietales Buža, Črna y Rosinjola. Los aceites de oliva vírgenes almacenados a bajas temperaturas mantienen mejores propiedades de calidad que los aceites almacenados a temperatura ambiente. Se encontró una disminución no significativa de los fenoles totales después de 12 meses de almacenamiento a todas las temperaturas estudiadas. Los compuestos volátiles totales, aldehídos, alcoholes y ésteres, en casi todas las muestras almacenadas, se mantuvieron sin cambios en comparación con los aceites frescos. Las cetonas totales incrementaron tras el almacenamiento, aunque a temperaturasmas bajas estos cambios fueron menos notables. El incremento de los indicadores de la oxidación hexanal y la relación hexanal/<em>E</em>-2-hexenal fue más bajo en los aceites almacenados a +4 °C. El almacenamiento a temperaturas inferiores a la temperatura ambiente ayuda a prolongar la vida útil de los aceites de oliva virgen extra, manteniendo la alta calidad y preservando el perfil de volátilesde un aceite fresco