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The nutritional quality and sensory properties of virgin olive oils (VOO) are strongly influenced by a complex endogenous enzyme system. The activity of these enzymes can be influenced by the process conditions during oil production. The aim of the present study was to determine the influence of flash thermal treatment (FTT) on lipoxygenase activity and on the formation of volatile compounds. Olive fruits from Istarska bjelica and Levantinka were used for this experiment. FTT was performed as a pretreatment to malaxation by rapid cooling or heating from 15 to 40 °C. Lipoxygenase was isolated from the olive paste after malaxation, and its activity was determined by measuring the concentration of hydroperoxides formed by the HPLC method. The volatile compounds of VOOs were analyzed by SPME - GC/MS. The results show that lipoxygenase activity is cultivar dependent, with Levantinka having significantly higher activity. Consequently, Levantinka VOOs have significantly higher concentrations of lipoxygenase pathway volatile compounds. FTT had no significant effect on lipoxygenase activity, although the trend of decreasing activity with increasing temperature was observed. However, volatile compounds of the produced oils were temperature dependent, and their concentration increases from 15 °C to 20 °C for Levantinka and to 25 °C for Istarska bjelica. Thereafter, it gradually decreases with increasing temperature. The concentration of secondary oxidation products was also determined to determine the influence of the temperature on the oxidation processes. Neither the cultivar nor the FTT had any effect on the oxidation products.

The aim of the present study was to investigate the effect of fertilization practices, especially with nitrogen (N), on N leaf status, fruit and oil yield, and oil quality parameters in orchards of Central Dalmatia. Questionnaires done by more than 100 olive growers revealed that fertilization practices vary widely. Based on the data obtained, 22 orchards with most prevailing practices in N application were selected for detailed soil, leaf and fruit analyses. The samples were taken from trees of the Oblica cultivar. N concentration in leaves averaged 1, 69% and ranged from 1.09 do 2.36% and correlated mainly with the intensity of agrotechnical prctices and fertilizer use expressed in the questionnaires. Based on results from 22 orchards, an additional subselection of 9 orchards with low, optimal nad high N leaf concentration was made. Hand-picked olives had on average 15, 5% of oil, fruit N concentration ranged from 0.43 to 0.71% ; with an average of 0.57%. The results showed correlation between N level in leaves and fruits, which was more pronounced in leaves with optimal N status. It was also found that N concentration in fruits was higher with lower K concentration in leaves. Significant negative correlation was found between N content in fruits and phenolic content in virgin olive oil, with increased N leading to sharp decrease in phenols in oil. As a basis for future studies on N nutrition in olive, fertilization experiment with three N supply levels was established on the cultivar Oblica.

Endogenous olive enzymes represent a crucial link between fruit composition and the nutritional and sensory characteristics of virgin olive oil. Enzymes such as β-glucosidase, polyphenol oxidase and peroxidase influence the content and composition of polyphenols, the main antioxidants in virgin olive oils. Lipoxygenase and hydroperoxide lyase convert fatty acids into volatile components responsible for the specific sensory properties of the oil. The aim of the present study was to determine the influence of fruit ripeness on the enzymatic activity of β-glucosidase, polyphenol oxidase, peroxidase and lipoxygenase in four Croatian autochthonous olive cultivars. For this experiment, olive fruits from two Dalmatian (Oblica and Levantinka) and two Istrian cultivars (Rosulja and Istarska bjelica) grown in their area of origin were harvested on three different harvest dates, from October 28 to November 9, 2021. The β-glucosidase, polyphenol oxidase and peroxidase were isolated from the acetone powder of the paste. The activity of these enzymes was determined spectrophotometrically, and the formation of p-nitrophenol from p-nitrophenyl glucopyranoside was measured for β-glucosidase, the formation of o-quinone from catechol for polyphenol oxidase, and the formation of tetraguaiacol from guaiacol for peroxidase. Lipoxygenase was isolated directly from olive paste, and its activity was determined by measuring the concentration of formed hydroperoxides by HPLC. The activity of β-glucosidase was detected only in a few samples, which was not sufficient to determine the influence of the factors studied on its activity. Polyphenol oxidase activity increased between the first and second harvest dates, and this increase was significantly higher in the Istrian cultivars. At later harvest dates, the activity decreased, but to a greater extent in the Dalmatian varieties. Peroxidase activity was significantly affected by both ripening and cultivar. Istrian cultivars had significantly higher peroxidase activity than Dalmatian cultivars. The activity was lower in riper fruits, with the exception of Levantinka, which had the highest activity in ripe fruits. Lipoxygenase activity was influenced primarily by harvest date: on the first date, activity was highest in Rosulja and Levantinka, on the second date in Istarska bjelica, and on the third date in Oblica. Throughout the harvest period, lipoxygenase activity was higher in Rosulja and Levantinka than in the other two cultivars.

Innovative technologies are being widely studied for their application in the production of virgin olive oil. Flash thermal treatment is one of these techniques, since the regulation of temperature allows control over complex enzyme systems that affect the nutritional value, oxidative stability and sensory profile of virgin olive oil [1-3]. The aim of this study was to determine the effects of flash thermal treatment (both cooling and heating) on the antioxidant activity of virgin olive oil from four different varieties (Oblica, Rosulja, Istarska bijelica and Levantinka). Flash thermal treatment was applied at 6 different temperatures in the range of 15-40 °C. It was used as a malaxation pretreatment for the production of virgin olive oil on a laboratory scale using the Abencor system. The antioxidant activity of the produced oils was determined using the DPPH method previously described by Kraljić et al [4]. The results show a significant influence of the variety and pretreatment on the antioxidant activity of virgin olive oil, as well as their interaction. Rosulja had the highest antioxidant activity (90.8% on average) compared to the other three varieties (84.3, 75.6 and 74.8% for Oblica, Istarska bijelica and Levantinka, respectively). In relation to the applied flash thermal treatment, Oblica, Rosulja and Levantinka showed significantly higher antioxidant activity at the highest temperature (40 °C), while Istarska bijelica responded better to mild temperatures (20-30 °C).

Olea europaea L. products such as extra virgin olive oils and olive leaves contain a wide variety of bioactive compounds that are profoundly analyzed for their various pharmacological properties. Scientific data on composition analyses of olive by-products such as olive milled waste, fruit pulp and seeds exist, however, information’s regarding the phenolic composition of olive organs as buds and/or flowers are available really scarce. Phenolic compounds in plants are of considerable physiological and morphological importance, playing an important role in pigmentation, growth, and reproduction, but also for resistance to pathogens. Therefore, the aim of this study was to characterize olive buds and open flowers of two Dalmatian cultivars ‘Oblica’ and ‘Lastovka’, and determine whether these two cultivars differ in phenol composition within the analyzed organs. From the buds and open flowers polar fractions were extracted (3 of each cultivar) using solid–liquid extraction with hydro-alcoholic solvent, while the extracts were analyzed using high performance liquid chromatography. Among twenty-three identified compounds classified into groups that have been characteristic for olive products as secoiridoids, phenolic acids, phenolic alcohols, flavonoids, and lignans, oleacin and oleuropin were the most abundant in olive buds of both studied cultivars. Their significantly higher content had ‘Lastovka’ compering to ‘Oblica’. In ‘Oblica’ open flowers oleacin and more over oleuropein content increases relatively to buds, although the highest increase was established for the verbascoside that was most abundant compound in ‘Oblica’s open flowers. For ‘Lastovka’ similar trend of increase was visible with an indication that the highest proportion recorded in ‘Lastovka’ open flowers was oleacin. Except phenolic’s, dynamics of anthocyanins cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside was followed. This data are the first report on the characterisation of phenolic compounds in buds and open flowers of the Croatian olive cultivars.

Korištenje podloga različito utječu na rast i razvoj rajčice te na kvalitetu ploda. Stoga je cilj ovog rada bio utvrditi utjecaj uzgoja na rzličitim podlogama na kvalitetu ploda rajčice. Pokus s kultivarom rajčice Matissimo F1, cijepljenim na sedam komercijalnih podloga za rajčicu Arnold (A) DR0141TX (DR), Maxifort (MX), Multifort (MF), Optifort (OF), Emperador (EM) i Suzuka (S) je postavljen u plasteniku na području Trogira u proljetno-ljetnoj sezoni. Biljke su posađene u tlo na PE crni film na razmak 50 x 140 cm i uzgojene su na dvije grane. Rani prinos bio je veći kod A (3, 95 t 1000 m-2) i EM (3, 84 t 1000 m-2), dok je ukupni najveći prinos bio na podlozi EM (33, 15 t 1000 m- 2). Plodovi uzgojeni na MF imali su veći paramter boje a* i h (24, 5 i 51, 6). Boja mesa ploda a* ovisila je o podlozi i poziciji mjerenja. Rub ploda najcrveniji je kod MF (13, 6) i EM (13, 5), dok je zona sjemena najmanje crvena kod MX (11, 9) i EM (13, 4). Središnji dio ploda najcrveniji je kod podloga OF (24, 4) i A (23, 1). Najviši udio topivih šećera postigli su plodovi uzgojeni na OF i S (3, 95° Brix) dok je najmanji utvrđenna MX (3, 2° Brix). Kod A izmjeren je najvši EC soka ploda (4, 96 dS m-1), dok je najviši pH zabilježen na S (4, 33). Najveći gubitak mase ploda zabilježen je sedmog dana čuvanja kod DR (3 %). Čvršće plodove imale su biljke uzgojene na DR, OF, MX i EM. Iako su podloge različito utjecale na promatrana svojstva, podloga EM se ističe po prinosu, boji mesa i čvrstoći.

U okviru projekta ''Bioraznolikost i molekularno oplemenjivanje bilja'' provedena je molekularna karakterizacija divljih i kultiviranih maslina u Hrvatskoj upotrebom 12 SSR (Simple Sequence Repeates) markera s ciljem dobivanja molekularnih profila specifičnih za genotipove uključene u ovo istraživanje. Sorte maslina smo prikupili iz kolekcijskih i proizvodnih nasada, dok su divlje masline izdvojene iz devet populacija s područja otoka Brijuna, Paga, Dugog otoka, Šolte, Hvara, Visa, Lastova, Mljeta i poluotoka Pelješca. Rezultati su pokazali jedinstvene profile za mnoge sorte i divlje masline te izdvojili tri slučaja sinonimije. Dendrogram izrađen metodom neighbor- joining je razdvojio grupu divljih od kultiviranih genotipova. Sorte su se većinom grupirale u zajedno, ali su pokazale i povezanost s divljim maslinama. Dobiveni rezultati su istaknuto bogatstvo genetskih resursa masline u Hrvatskoj, dajući informacije za njihovo očuvanje.

Olive fruit fly (Bactrocera oleae, Rossi) and olive moth (Prays oleae, Bern.) are the most economically important olive pests, causing yield losses in all olive-growing areas where they are detected. For years, the use of pesticides was the main method of controlling them, and their intensive use had negative effects on the environment. Therefore, the EU aims to reduce the use of pesticides by 50% by 2030 and 100% by 2050. For all these reasons, more effective non-pesticidal baits are needed for monitoring and/or control of B. oleae and P. oleae. Current knowledge indicates that several insect species are attracted to natural volatiles, including pheromones, host plants, yeasts, and bacterial volatiles. Since the interaction between olive trees and olive pests has not been adequately studied, the objective of this study was to identify olive tree volatiles that might be responsible for attracting B. oleae and P. oleae and to test them in olive orchards. During the study, about 70 different volatiles were identified from olive flower buds, 4-6 mm fruits and leaves, and 100 different volatiles were identified from olive fruits at three stages of ripeness (green, semi-ripe and ripe), mainly belonging to the groups of esters, saturated hydrocarbons, aldehydes, alcohols, terpenes and sesquiterpenes.These results are used to identify volatiles that could be responsible for olive moth attraction. Therefore, selected volatiles will be tested in delta traps in several olive orchards. Volatiles that could be responsible for olive fruit fly attraction will also be selected and tested on yellow sticky traps in other olive orchards. The results of our research could provide answers to many questions about the relationship between olives and pests. Finding volatiles that could be responsible for attracting harmful species could lead to the development and improvement of new attractants that could be a useful tool for monitoring and/or controlling B. oleae and P. oleae in the future.

Maslinin moljac (Prays oleae Bern.) jedan je od najvažnijih štetnika masline koji svake godine čini štete. Godinama je jedna od glavih mjera suzbijanja istog bila primjena pesticida, čija je intenzivna uporaba imala negativan utjecaj na okoliš. Stoga je EU uvođenjem Europskog zelenog plana obvezala svoje članice na smanjenje utroška pesticida za 50 % do 2030. godine. te 100 % do 2050. godine. Zbog svega navedenog prijeko je potrebno iznaći nova rješenja koja bi bila učinkovita u suzbijanju moljca i ekološki povoljna za okoliš. Trenutne spoznaje govore da različite vrste kukaca privlače hlapive tvari biljke domaćina. Kako interakcija masline i moljca još uvijek nije istraživana, cilj istraživanja je bio identificirati hlapive tvari masline koje bi mogle biti odgovorne za privlačenje istog, te ih testirati u maslinicima. Na odabranim sortama masline uzorkovan je biljni materijal te su identificirane hlapive tvari pomoću HS-SPME/GC-MS uređaja. Tijekom istraživanja identificirano je oko 70 različitih hlapivih tvari, među kojima su odabrana dva aldehida, dva alkohola i ester, te su testirani pojedinačno i u kombinacijama u maslinicima pomoću delta lovki. Rezultati ovog istraživanja su pokazali kako su alkohol i kombinacija aldehid:alkohol:ester, kao dodatak feromonu, privukle puno veći broj moljaca od lovki koje sadrže samo feromon. Ovo otkriće može dovesti do razvoja novog i poboljšanog mamaca za maslinovog moljca, koji bi se u budućnosti mogao koristiti za monitoring i/ili suzbijanje istog.

The research activities of the project "Biodiversity and Molecular Plant Breeding" were conservation, phenotyping and genotyping of olive genetic resources in Croatia. During the field expeditions, nine populations of wild olives were selected and included in the study together with cultivars from the field collections at Institute for Adriatic Crops and from the production orchards. Qualitative and quantitative traits of leaf, fruit, stone and flower were assessed at 97 wild genotypes, 28 autochthonous and 35 foreign cultivars. Fruit and stone traits showed high discriminatory capacity between wild olives and cultivars. The samples of 223 genotypes were molecularly characterized using 12 SSR (Simple Sequence Repeats) markers. The results showed high genetic variability of the Croatian germplasm separating the wild genotypes from the cultivated ones. Chemical and sensory profiling of 54 monovarietal extra virgin olive oils showed that fatty acids, phenolic content and sensory profile are predominantly characteristics of a cultivar. According to obtained results the plant material was propagated and used for establishment of new collection orchard and in greenhouse experiments to assess the sensitivity of different genotypes to abiotic and biotic stresses. The alternate bearing of Oblica, the main Croatian olive cultivar was studied in production orchard. The trees with different fruit load showed differences in flower and fruit morphology as in fruit and oil yields. The olive research group at Institute for Adriatic Crops will continue to work in selection, evaluation and preservation of olive autochthonous and wild genotypes.

The olive fruit fly (Bactrocera oleae, Rossi) and olive moth (Prays oleae, Bern.) are economically the most important olive pests, causing yield losses in all olive growing areas where detected. For years, the use of pesticides was the main method for their controlling, which intensive use had a negative effect on the environment. Therefore, the EU is seeking to reduce pesticide use by 50 % by 2030 and 100 % by 2050. Due to all the above, more effective non-pesticide lures for B. oleae and P. oleae monitoring and/or controlling are needed. Current knowledge suggests that different insect species are attracted by volatile natural compounds, including a pheromones, host-plant, yeasts and bacterial volatiles. Since the interaction between olive tree and olive pests has been purely investigated, the aim of this study was to identify the olive tree volatiles that could be responsible for B. oleae and P. oleae attracting, and to test them in olive orchards. Plant material was sampled on selected olive cultivars and volatiles were identified using HS- SPMEGC-MS. During investigation, around 70 different volatiles were identified from olive flower buds, fruits 4-6 mm and leaves, and 100 different volatiles from olive fruits in three ripening stages (green, half ripe and ripe), mostly belonging to the groups of esters, saturated hydrocarbons, aldehydes, alcohols, terpenes and sesquiterpenes. These results, as a pull of data will serve for identifying volatiles that could be responsible for olive moth attracting, thus selected volatiles will be tested in delta traps in multiple olive orchards. Volatiles that could be responsible for olive fruit fly attracting will be also selected and tested on yellow sticky traps in other olive orchards. The results of our research could provide answers to many concerns about the olive/pests relationship. Finding volatiles that could be responsible for attracting harmful species may lead to the development and improvement of new attractants, that could be a useful tool for monitoring and/or controlling of B. oleae and P. oleae in the future.

Kao jedna od najvažnijih mediteranskih voćnih vrsta, maslina (Olea europaea L.) je poznata kao bogat izvor fenola i drugih nutritivno važnih spojeva. Proteklih godina na Institutu za poljoprivredu i turizam provedena su brojna istraživanja vezana uz utjecaj ishrane masline na fenolne komponente lista ili maslinovog ulja.Temeljem odabranog seta podataka prikazanih u ovom radu, sorta 'Istarska bjelica' pokazala je najveću koncentraciju oleuropeina u listu i ukupnih fenola u maslinovom ulju. U hidroponskom pokusu smanjena razina magnezija u hranivoj otopini povećala je, a niska razina mangana, cinka i bakra smanjila koncentraciju ukupnih fenola u listu masline sorte 'Istarska bjelica'. Folijarna gnojidba sumporom imala je pozitivan učinak na količinu ulja po stablu u rodnoj godini neovisno o proučavanoj sorti.

The olive tree (Olea europaea L.) is an important fruit tree species in all Mediterranean countries, including Croatia, which is characterized by a fair number of indigenous, locally grown varieties, and by a rich heritage of wild olive trees still found on numerous islands along the Adriatic coast. In the framework of the project "Biodiversity and Molecular Plant Breeding", the samples of 223 olive varieties and wild olives were collected from different locations in the olive growing area and molecularly characterized using 12 SSR (Simple Sequence Repeats) markers. The results showed a unique profile for most cultivars and wild trees, except for three cases of synonymy, probably attributable to misnaming. Overall, the Croatian germplasm showed high genetic variability. The neighbor-joining dendrogram separated a group of wild genotypes originated mostly from the middle and southern Dalmatian islands. Cultivated genotypes mostly clustered together but they also showed relationship with wild germplasm. The results obtained underlined the richness of the genetic resources of the olive tree in Croatia, providing information for the protection of genetic material and monovarietal oils.

Godinama je zaštita masline (Olea europea L.) od štetočinja, kod nas i u svijetu, bila usmjerena samo na uporabu pesticida, što je u zadnjih nekoliko desetljeća rezultiralo negativnim učinkom na okoliš. Očuvanje biološke ravnoteže i cjelokupnog agroekosustava, ključni je problem današnjice. Intenzivne agrotehničke mjere narušavaju sklad biocenoze maslinika, stoga se danas u maslinarstvu sve više pribjegava integriranom ili ekološki prihvatljivom sustavu proizvodnje u kojima je ograničena uporaba pesticida. Dosadašnja istraživanja pokazuju da prirodne hlapive tvari, uključujući feromone, hlapive tvari biljke domaćina, kvasaca i bakterija imaju utjecaj na ponašanje različitih vrsta kukaca. Cilj ovog istraživanja je izolacija i identifikacija hlapivih tvari masline te pronalazak onih koje bi mogle biti odgovorne za privlačenje najvažnijih štetnika masline. U sklopu istraživanja izolirane su i identificirane biljne hlapive tvari cvijeta, ploda i lista Oblice u različitim fazama zrelosti ploda pomoću HS-SPME/GC-MS uređaja. Identificirano je više od 40 hlapivih tvari koji većinski pripadaju skupinama estera, zasićenih ugljikovodika, aldehida, alkohola, terpena i seskviterpena. Rezultati istraživanja mogli bi dati odgovore na mnoge nedoumice o uzajamnom odnosu maslina/štetnik, koji bi rezultirali velikim doprinosom u zaštiti bilja RH, ali i u svijetu.

Šipak (Punica granatum L.) se tradicionalno uzgaja u mediteranskom dijelu Republike Hrvatske, a najviše na području srednje i južne Dalmacije. Na navedenom području izdvojene su najinteresantnije primke te umnožene i posađene u kolekcijski nasad nacionalne banke biljnih gena RH smještenom na Institutu za jadranske kulture Split. Tijekom četverogodišnjeg istraživanja provedena je morfološka karakterizacija 19 primki iz kolekcije od kojih je 9 upisanih u CPGRD bazu, 7 je potencijalnih i 3 su introducirane primke. Morfološka karakterizacija provedena je temeljem UPOV deskriptora za šipak. Opisana su kvantitativna i kvalitativna svojstva stabla, lista, cvijeta i ploda. Analizom rezultata utvrđena je značajna morfološka raznolikost istraživanih primki. Deset primki pripada skupini slatkih sorata, a odlikuju se svjetlijom bojom kore (zeleno-žuto-roza). Slatko - kisele i kisele sorte odlikuju se intenzivno crvenom bojom kore. Introducirane primke imaju tamniju boju kore i arilusa te su slatko kiselog do kiselog okusa pogodne za preradu.

Maslina (Olea europaea L.) je mediterska voćna vrsta koja se u pravilu uzgaja na plitkom i skeletnom tlu s niskim kapacitetom tla za vodu u zoni korjena. Na takvim tlima je navodnjavanje neizostavna agrotehnička mjera u uzgoju i proizvodnji visoko kvalitetnog maslinovog ulja. Cilj ovog rada je utvrditi kako različiti obroci vode i njihov broj kod navodnavanja na heterogenom i skeletnom tlu utječe na kvalitetu i sastav djevičanskog maslinovog ulja dobivenog od plodova introducirane sorte maslina Coratina. Poljski pokus je proveden u sklopu projekta „SAN – Smart Agriculture Network“ (SAN - KK.01.2.1.01.0100) na 24 stabla masline sorte ‘Coratina’ u 2019. godini na lokaciji Žman (Dugi otok). Navodnjavanje je provedeno pomoću sustava kap na kap sa četiri varijante u tri ponavaljanja. Varijante u pokusu predstavljale su primjenjene načine navodnjavanja: K-Kontrola - stabla masline bez navodnjavanja u vegetaciji (0 L vode po stablu), T1 - proizvođačka praksa (obroke je određivao proizvođač prema iskustvu (448 L vode po stablu u pet obroka)), T2 - SAN praksa (obroci su određivani s obzirom na evapotraspiraciju i fenofazu razvoja masline, s do 80 % poljskog kapaciteta tla za vodu, isto kako će ih određivati i SAN tehnologija koja je u razvoju - 560 L vode po stablu u osam obroka) i T3 – dodavanje obroka vode do 100% od izračunate evapotraspiracije (800 L vode po stablu u osam obroka). Određen je poljski kapacitet tla za vodu, a evapotranspiracija je izračunata pomoću meteopostaje tipa Pinova. Plodovi maslina ubrani su s 12 stabala (3 stabla po tretmanu) i prerađeni odvojeno u ulje korištenjem Abencor sustava. Statističkom obradom podataka (jednosmjernom analizom varijance i povratnim testom (Duncan)) istražen je utjecaj navodnjavanja na osnovne parametre kvalitete ulja: antioksidacijska aktivnost, sastav masnih kiselina i udio fenolnih tvari. Mjeranja osnovne analize ulja su pokazala da postoji razlika između peroksidnog broja, slobodnih masni kiselina, i karatenoida koji su bili najveći na kontroli, dok kod krolofila i K brojeva nije utvrđena razlika. Antioksidativna aktivnost maslinovog ulja bila je najveća na kontroli u odnosu na ostale tretmane. Utvrđen je utjecaj istraživenih praksi navodnjavanja na sedam od petnaest ispitivanih masnih kiselina. Postoje razlike kod polifenolnog sastav ulja i to kod hidroksitirosola i tirosola koji su bili najveći na T3, a najmanji na kontroli. Navodnjavanje masline u istraživanim praksama utjecalo je na sastav i kemijske parametre maslinovog ulja kod sorte Coratina na lokaciji Žman.

Onion (Allium cepa L.) is an important horticultural crop with a worldwide production of 93 168 548 tons while in 2016 in Croatia 26 858 tons of dry bulb onion were harvested, with an average yield exceeding 32 t ha-1 (FAOSTAT). Critical decision that onion growers must address is optimization of plant density which determines cost, plant yield and bulb quality. Objective of this study was to evaluate the effects of different within and between row spacings on Istrian purple and yellow onion bulb characteristics. The field experiment was conducted during two vegetative seasons and was set up as a randomized block design with two factors: 20, 30 and 50 cm between row spacing and 10, 15 and 20 cm within row spacing. Bulb weight increased as between row spacing increased for Istrian purple and red onion, while in row plant spacing had significant effect only for yellow onion. Row spacing had similar effect on Istrian purple and yellow onion bulb height and diameter (P < 0.001 for both genotypes). Flavonoid, anthocyanin and sugar content of both genotypes were less affected by different row spacings than observed bulb morphological traits. These results suggest that it is possible to adjust planting density of Istrian purple and yellow onion in order to obtain marketable bulbs without significant changes in bulb quality.

Fruit samples of domestic (‘Barski slatki’, ‘Ciparski’, ‘Glavaš’ and ‘Sladun’) and foreign pomegranate cultivars (‘Granada’, ‘Hicaznar’ and ‘Wonderful’) were collected in productive pomegranate orchard in Metković (Croatia) and compared their pomological and chemical properties. The results on the main pomological and quality traits indicated significant statistical differences among domestic and foreign cultivars. Fruit weight of investigated cultivars varied from 510.5 to 355.1 g and the highest was recorded in ‘Glavaš’, while difference in fruit weight between other cultivars was not found. Color of peel, arils and juice of domestic cultivars was yellow to red, red and light red to red, receptively, while in the foreign cultivars intensively red and dark red. Arils yield of ‘Barski slatki’ and ‘Ciparski’ (57.7 and 60.8%, receptively) was higher compared with other investigated cultivars. Juice yield of domestic cultivars was higher than that of foreign. Total soluble solid (TSS) of ‘Hicaznar’ (18.6%) was higher than that of ‘Barski slatki’ (17.0%), ‘Ciparski’ (14.7%) and ‘Wonderful’ (16.6%). Total acidity (TA) of ‘Glavaš’ (2.24%) and ‘Hicaznar’ (2.08%) was the highest while of ‘Barski slatki (0.58%), ‘Ciparski’ (0.37%) and ‘Sladun’ (0.59%) the lowest. According to the TA and (TSS/TA) ‘Glavaš’ and foreign investigated cultivars belonged to the group of sour-sweet cultivars while ‘Barski slatki’, ‘Ciparski’ and ‘Sladun’ belonged to the sweet cultivars. Foreign cultivars had higher total phenolic content (TPC) that ranged from 679.6 to 906.6 mg 100 g-1 d.w., than domestic ones. ‘Hicaznar’ stood out as a cultivar with the highest TPC and anthocyanin content (86.3 mg 100 g-1 d.w.). Non-flavonoid content in studied cultivars ranged from 160.6 to 385.5 mg 100 g-1 d.w. and antioxidant activity measured by 1, 1-diphenyl-2-picrylhydrazyl from 60.2 to 74.5%. Results of this survey are a basis for use defining of the pomegranate fruit.

Virgin olive oil (VOO) has significant health impact because of its peculiar chemical composition. Among phenolic compounds in VOO, the secoiridoid derivates oleocanthal and oleacein are responsible for antioxidant, antimicrobial, anticancer and hypoglycemic activity. Furthermore, oleocanthal showed stronger anti-inflammatory effect compared to ibuprofen. In this study, we investigated the accumulation of oleocanthal, oleacein and other phenolic compounds (hydroxytyrosol, tyrosol, oleuropein aglycon, apigenin, luteolin and ligstroside aglicon) in monovarietal VOOs obtained from Croatian autochthonous cultivar Oblica. Olive fruits were harvested in 2016 at the same ripening stage from olive groves spread over all Croatian olive cultivated regions. Subsequently olive fruits were processed in oil under the same conditions using laboratory system Abencor mc2. Phenolic extracts were prepared using liquid-liquid extraction with methanol:water mixture (60:40 v/v). Phenolic extracts were analyzed by a 1200 Series liquid chromatograph coupled to a triple quadrupole detector, equipped with ESI source. The results show different concentrations of hydroxytirosol, oleocanthal, oleuropein aglycon and lygstroside aglycon regarding olive cultivation region. Indeed, hydroxytirosol had the lowest concentrations in north Dalmatia while oleocanthal had the highest concentrations in middle Dalmatia, with no differences noticed among other olive regions. The oleocanthal concentrations varied from 112 up to 1082 mg kg-1, while oleacein concentrations from 80 up to 942 mg kg-1. Overall, the results indicated significant variability of phenolic compounds in VOOs from different Croatian regions, thus indicating possible superior therapeutic features from specific VOOs.

Luk (Allium cepa L.) je važna povrćarska kultura te se uzgaja na cijelom području Hrvatske. Istarski ljubičasti i žuti luk nalaze se na listi čuvanih sorti Republike Hrvatske te se tradicionalno uzgajaju na obalnom području Istre. Varijabilnost svojstava lukovice kod ovih sorti je velika, jer ih već generacijama održavaju proizvođači bez kontrole oprašivanja. Tradicionalno se sade iz presadnica tijekom jeseni, te se lukovice beru od lipnja za potrošnju tijekom ljeta. Cilj ovog rada je bio procijeniti varijabilnost svojstava glavica Istarskog ljubičastog i žutog luka. Rezultati su pokazali da postoji velika varijabilnost u boji mesa i pokožice, te je koeficijent varijacije (CV) za boju mesa i pokožice iznosio 11% i 7% kod crvenog, te oko 4 i 7% kod žutog luka. Također, visoki CV (od 7 – 20%) su uočeni za broj ljuski, debljinu pokožice, čvrstoću glavice te sadržaj šećera. Nešto manji CV je uočen za pH lukovice (3 i 5% kod žutog i crvenog luka), te za ukupan sadržaj kiselina (CV ~ 8% za obje sorte). Vrlo veliki CV je uočen kod visine glavice, promjera glavice i mase glavice (CV 17 – 21%, 24 – 30% i 54 – 67%). Koeficijenti varijacije za sadržaj flavonoida su bili veliki, nešto viši za crveni luk (CV 39 – 49%) nego za žuti (CV 32 – 38%). Kod crvenog luka uočena je vrlo velika varijabilnost za sadržaj antocijana. Rezultati ovog istraživanja ukazuju na veliku varijabilnost praćenih svojstava kod obje sorte te na mogućnosti usmjeravanja procesa selekcije prema poželjnim agronomskim i gospodarskim svojstivma.

Analysis of elements in Extra Virgin Olive Oil (EVOO) samples is challenging due to the complex matrix as well as their very low concentrations in oil. Optimization of a previously proposed analytical method consisting of ultrasonic acid extraction and subsequent ICP-MS detection is now allowing determination of 27 elements in EVOO a low pg g-1 level for trace elements. Furthermore, EVOO samples are likely to contain residual pomace, which potentially can influence the elements concentration and distribution. Indeed, our study revealed that pomace residues, when present in EVOO even at small quantity (1 g kg-1), significantly alter concentrations and relative proportions of many elements present in EVOO. Comparative analyses of EVOO samples with and without centrifugation prior to ultrasonic acid extraction confirmed significant influence of pomace residues on elements concentrations. Therefore, an adequate sample pre-treatment (removal of pomace residue) through centrifugation is essential for determining real multi-elemental composition of olive oil. This is critical in application of EVOO multi-element composition in traceability studies and determination of geographic origin of oil.

Extra virgin olive oil is obtained by mechanical processing of olive fruits at temperature up to 27 ºC in each processing step, as a guarantee of the highest oil quality. With prolonged malaxation time the oil yield can increase, but the quality of obtained oil is usually lower. In this paper the influence of different processing conditions (temperature and malaxation time) in monovarietal olive oils from 'Oblica' has been studied, in order to determine better overall quality, antioxidant characteristics and longer shelf life. Different malaxation temperatures (26, 36, 46 ºC) were applied during olive processing on laboratory scale using Abencor mc2 system. For each temperature, the influence of several malaxation times were also examined (30, 45, 60 min). The analyses of free fatty acid, peroxide value, UV spectrophotometric indices was perforemd according to official EEC methods (2568/91). Total phenols content (TPC) was determined using the Folin–Ciocalteau method (Gutfinger, 1981). The sensory evaluation of olive oils was performed according IOC (2007) method. Oxidative stability was measured using Rancimat apparatus while antioxidant activity was detected using DPPH antioxidant assay following the method described by Kalantzakis et al. (2006). Both oxidative stability and antioxidant activity was carried out in fresh oils and during 12 months of oil storage in dark place at the room temperature. Prolonged malaxation had the strongest influence on K-numbers, especially at the temperature of 46 ºC so oils obtained under this conditions were in the category of lampante non-edible oils. Strangely and unexpected, these same oils had very high TPC. The best overall quality was detected in oils obtained 26oC and during shortest malaxation time (30 min.). Same oils had the highest TPC and the best oxidative stability. Sensory analyses of investigated oils showed the highest score for oils processed at 26 ºC and 36 ºC and 30 min of malaxation. The fastest degradation of overall quality was noticed in oils produced at 46 oC i 45 min of malaxation.

Cilj je bio utvrditi komponente vegetativnog i generativnog rasta, prinosa i kvalitete ploda rajčice cijepljene na vlastiti korijen (pozitivna kontrola) kao i na Solanum podloge u uvjetima reduciranog navodnjavanja. Biljke uzgajane s deficitarnim navodnjavanjem i djelomičnim zasušivanjem korijena imale 30% veću efikasnost korištenja vode. Također, biljke uzgajane na podlogama su očekivano pokazale veću efikasnost korištenja vode u odnosu na prinos svježih plodova rajčice. Istraživanja su pokazala da uzgoj na 2 izboja/grane rajčice cijepljene na Solanum podloge uz deficitarno navodnjavanje naglašeno smanjuje troškove bez velikog utjecaja na prihod.

The volatile compounds from virgin olive oil (VOO) are chemical species responsible for its specific flavour. This group of compounds consists mainly of C5 and C6 volatiles that are biogenerated from polyunsaturated fatty acids via lipoxygenase pathway. In this paper the composition of volatile compounds, total phenolic content and sensory profile of monovarietal VOOs from four Dalmatian most common cultivars: Oblica, Lastovka, Levantinka and Krvavica were studied. Fruits from each variety were handpicked at the same ripening stage and processed separately in oil under the same conditions using laboratory oil mill Abencor mc2. All analyzed VOOs were within limits established for extra virgin olive oil category based on chemical parameters. Total phenolic content (TP) of obtained oils were determined spectrophotometrically using modified Gutfinger method and expressed as caffeic acid. The highest TP value was detected in Oblica and Levantinka oils (482.32 mg/kg and 398.85 mg/kg, respectively). Volatile composition of analyzed monovarietal olive oils was determined using headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME/GC-MS). The most prevalent volatile compound was C6 aldehyde E- 2-hexenal, that contributes to green, fruity, bitter and astringent sensory characteristic of olive oil. The highest value for E-2-hexenal was detected in Levantinka oils (75.89% of total peak area), followed by Lastovka (55.27%) and Oblica (54.86%). In the same time, Lastovka oils had the highest ammount of hexanal (25.72%), C6 aldehide associated with sensory characteristics of green fruitiness, apple and grass. Quantitative descriptive sensory analysis of studied olive oil samples were carried out by a sensory panel using IOC methodology. The sensory profile of Lastovka oil was characterized by medium intensity of olive fruity, green leaves, apple and almonds, strong bitterness and medium pungency. Krvavica oil sensory profile showed the mildest intensity of bitter and pungent of among all analysed oils. Mild to medium fruitiness with grass and ripe apple notes are olfactory characteristics of Krvavica oils.

Deficitarno navodnjavanje (DI) i izmjenično djelomično zasušivanje korijena (PRD) su tehnike uštede vode, dok je cijepljenje na podloge koristan alat za prevladavanje abiotskih stresova u plodovitom povrću. Cilj ovog rada bio je utvrditi utjecaj deficitarnog navodnjavanja i djelomičnog zasušivanja korijena na rast i prinos cijepljene rajčice. Rajčice sorte Clarabella, cijepljene na vlastitom korijenu i cijepljene na dvije Solanum podloge Emperador i Maxifort, uzgajane su tlu u plasteniku s tri tipa navodnjavanja: DI ; PRD i potpuno navodnjavanje (FI). Visina biljaka rajčice nije se razlikovala među tretmanima, dok su biljaka cijepljene na podloge imale više listova u odnosu na samocijepljene rajčice. Uzmajući u obzir sva tri tipa navodnjavanja najveći prinos je zabilježen kod biljaka na podlozi Emperador (6, 54 kg), a najmanje rajčice je ubrano kod samocijepljenih biljaka (4, 90 kg). Biljke navodnjavane s DI i PRD imale su više plodova od FI biljaka. Najveći rani prinos imale su biljke na podlozi Maxifort pri DI, dok su iste biljke imale najmanji rani prinos pri PRD. Najveću prosječnu masu ploda (317 g) imale su biljke na podlozi Emperador uzgajane sa PRD dok su najmanju masu ploda (263 g) ostvarile samocijepljene biljke pri FI i DI. Rezultati pokazuju efikasnost DI i PRD vezano za poboljšani rast i ostvareni prinos cijepljenih rajčica u odnosu na potpuno navodnjavanje.

Virgin olive oil (VOO) is unique vegetable oil that is obtained directly from olive fruit using only mechanical processing. That way it contains a great number of valuable bioactive compounds that are responsible for its specific taste and aroma, but also for health promoting beneficial properties. The type of technological process for olive oil production has strong influence on quality and chemical composition of produced oil. In this paper we studied the influence of different technological processes on the quality and fatty acid profile of VOOs produced in Dalmatia. We took in consideration traditional processing using hydraulic press, modern centrifugal system by two phases and laboratory olive oil plant (Abencor mc2) with controlled producing parameters. In all obtained samples we analyzed basic quality indicators (FFA - free fatty acids expressed % of oleic acid, PV – peroxide value expressed as mmol O2/kg, K-numbers (UV spectrophotometric indices K232 and K270) [1], total phenolic content (TPC) expressed as mg of gallic acid per kg of oil [2], fatty acid composition [3, 4] and also sensory analyses according official EC [1] and IOC methodology [5]. All oils produced by centrifugal process and by laboratory oil mill were in category of extra virgin olive oil, while majority of samples obtained by traditional hydraulic press were in lower categories. Also sensory analyses confirmed lower quality for traditionally produced olive oils. Oils produced by laboratory plant had stronger positive sensory attributes (fruitiness, bitterness and pungency). Values for TPC showed notable differences among oil samples depending on processing type, as well as fatty acid profile for certain olive oil which is discussed in this paper.

Phenols are responsible for virgin olive oil (VOO) taste characteristics, and significantly determine VOO oxidative stability and shelf life, as well as its nutritive value. The content of phenols in VOO depends on many agronomic and technological factors, and olive fruit ripening degree and paste malaxation duration and temperature are among the most important. The aim of this study was to investigate the main effects and interactions of these three key factors on the content of phenols and related taste sensory characteristics of Oblica cv. (Olea europaea L.) VOO. Olives were picked at three ripening degrees as green (RD1), semi-ripe (RD2) and ripe (RD3), and processed by malaxation at 22 / 30 °C, for 30 / 60 min. The obtained oils were subjected to HPLC-DAD analysis of phenols, and sensory analysis by the official IOC method. The highest variability was observed for ripening degree, where later harvest caused the particular oleuropein and ligstroside aglycons, phenolic acids, acetoxypinoresinol, and vanillin to decrease. The amounts of the two major aglycons, 3, 4- DHPEA-EDA and p-HPEA-EDA mostly increased, but only at 30 ⁰C. The effect of higher malaxation temperature was significant for phenolic acids and flavonoids which mostly decreased, and for vanillin and the majority of secoiridoids which increased. The main effect of malaxation duration was relatively weak. For the majority of phenols the effects of the factors significantly interacted. Among many specific and unique outcomes, several clear patterns were noted. For the majority of phenols, the positive effect of higher malaxation temperature was found to intensify with ripening, peaking in RD3, most strongly for 3, 4-DHPEA-EDA and p-HDEA-EDA. Ripening degree also interacted with malaxation duration. At RD1, except for vanillin and p-HPEA-EDA, a negative effect of longer duration was observed, while at RD3 longer malaxation caused a reversed effect and all phenols increased, but exclusively at 22 ⁰C. Desirable taste sensory attributes correlated positively with particular main phenols. A decrease of bitterness and pungency, and an increase in sweetness was observed along ripening. Bitterness and pungency were enhanced by the higher malaxation temperature. This work has been supported in part by Croatian Science Foundation under the project UIP-2014-09- 1194.

To investigate the effect of olive fruit maturity on virgin olive oil phenolic composition and related sensory properties, Istarska bjelica (IB) and Oblica (OB) olives were harvested at three dates covering the whole customary harvest period in the Croatian regions of Istria and Dalmatia, respectively. During maturation, IB olives did not change skin color significantly (which is a cultivar characteristic), while OB olives were picked as green, semi-ripe, and ripe. Olives were processed using a laboratory scale Abencor system, and the obtained oils were subjected to HPLC-DAD analysis of phenols. Sensory analysis of oils was performed by an accredited authorized panel using the official IOC method. Hydroxytyrosol, tyrosol, and hydroxytyrosol acetate increased with ripening in IB oils. In OB oils the same was observed for hydroxytyrosol acetate, while other simple phenols exhibited irregular fluctuations. Vanillic acid decreased proportionally with the maturation of IB olives, while in OB oils the same was observed also for vanillin and p-coumaric acid. Flavonoids and lignans increased with harvest date in IB, while during OB maturation acetoxypineoresinol decreased. Secoiridoids exhibited similar variation for both cultivars: the majority of oleuropein and ligstroside aglycons decreased with maturation, except for 3, 4-DHPEA-EDA and p-HPEA-EDA which surprisingly increased in OB. However, the decrease of other aglycons was much sharper in OB than in IB oils. Sensory analysis generally revealed a positive correlation between phenols amount and bitter and pungent sensory attributes of the oils, as well as their overall quality and cultivar typicity. This work has been supported in part by Croatian Science Foundation under the project UIP-2014-09-1194.

Maslina se uzgaja diljem Mediterana, a u priobalnom dijelu Republike Hrvatske je najbrojnija voćna vrsta. Plod masline je koštunica ovalnog oblika koja se sastoji od dva dijela, perikarpa i endokarpa. Karakteristike istih definira podjelu sorti na uljne, stolne i sorte kombiniranih svojstava. Rast i zrenje kombinacija su biokemijskih i fizioloških promjena genetski određenih, ali i dodatno ovisnih o okolišnim čimbenicima. Cilj istraživanja bio je odrediti i pratiti promjene fizikalnih parametara ploda važnih za rukovanje, obradu i projektiranje opreme, kao i odrediti udjel ulja u plodovima maslina 'Oblice' i 'Leccina', svojstva prema kojem se procjenjuje ekonomska vrijednost sorte. Za procjenu kvalitete ploda određeni su: masa ploda (g), duljina i širina ploda (mm), udio suhe tvari, udio ulja izražen na suhu tvar (%) i masu svježeg ploda masline u tri uzgojne godine. Pronađene su razlike između istraživanih sorti u masi, duljini i širini ploda, gdje je 'Oblica' značajno većih vrijednosti u odnosu na 'Leccino'. Sadržaj suhe tvari u 'Oblici' bio je u rasponu od 32, 0 do 45, 6%, dok se u 'Leccinu' kretao od 38, 7 do 52, 9%. Udio ulja izražen na suhu tvar raste sazrijevanjem plodova u obje istraživane sorte. Prosječna vrijednost udjela ulja 'Oblice' bila je 41, 5%, a 'Leccina' 36, 4%. Sorta nije imala značajan utjecaj na udio ulja u svježem plodu koji je prosječno u tri godine iznosio 16, 0%. Visoki udjeli ulja u plodovima obje sorte u svim stupnjevima zrelosti ukazuju na visok ekonomski potencijal. Informacije o promjenjivosti tijekom zrenja značajne su za proizvođače djevičanskih maslinovih ulja. Ispitani parametri pomoći će za određivanja optimalnog stupnja zrelosti plodova i doprinijeti karakterizaciji 'Oblice' i 'Leccina'.

Soil nutrient availability (determined by extraction) should be compared with plant nutrient uptake, but such information is scarce for olives. Similarly, there is little information regarding a relationship among total soil nutrients, available fractions and plant uptake as a basis for tracing geographic origins of olive oil. Olives grown on Terra rossa soils along the Adriatic coast had sufficient leaf nutrients concentrations, which contributed to the correlations between plant- available nutrients in soil and leaf nutrient concentrations being mostly non-significant. High leaf Cu concentrations (above toxicity thresholds) can be result of intensive fungicide applications at some locations.

Fruit samples of ‘Granada’, ‘Wonderful’ and ‘Hicaznar’ cultivars were collected in productive pomegranate orchard in Neretva valley, Metković (Croatia) and their pomological and chemical properties were compared. Significant differences among cultivars were noted between the studied traits. Fruit weight ranged from 429.37 g to 359.43 g and the lowest was recorded in cv. ‘Hicaznar’. Color of peel, aril and juice of all investigated cultivars was intensively red and dark red, respectively. ‘Granada’ and ‘Wonderful’ stood out with high juice yield compared with ‘Hicaznar’. Total soluble solid (TSS) of ‘Hicaznar’ (18.61%) was higher than that of ‘Wonderful’ (16.64%). Total acidity (TA) significantly differed among cultivars and ranged from 1.6% to 2.1%. According to the TSS/TA ratio investigated cultivars belong to the group of sour-sweet cultivars. Dissimilarity between cultivars was found in the phenolics content (TPC). It ranged from 679.6 to 906.6 mg/100 g D.W. where ‘Hicaznar’ stood out as a cultivar with highest TPC and also highest flavonoid and non-flavonoid content (521.1 mg/100 g D.W. and 385.5 mg/100 g D.W., respectively). In ‘Granada’ antioxidant activity measured by 1, 1-diphenyl-2- picrylhydrazyl was recorded for 64.1%, in ‘Wonderful’ 70.2% and the highest in ‘Hicaznar’ (74.5%). Results of this assessment are the basis for practical determination of the pomegranate use.

Monovarietal virgin olive oils have a special importance in the olive bio-diversity preservation. Ripening index is used mainly as a guideline to establish the optimum olive harvest time in order to produce high quality virgin olive oils with well-balanced oil yield and content of bioactive compounds. Influence of cultivar, year and growing location on fruit quality parameters during fruit ripening was studied. The present data provide information about the maturation patterns of the most important Croatian cultivar Oblica and Italian cultivar Leccino harvested at bi-weekly periods during three crop seasons. Ripening index, fruit dry matter content and oil content expressed on a dry matter (%) and the mass of fresh olives were analyzed. The fruits were processed by same way, using centrifugal extraction on Abencor laboratory oil mill, after which the extractability was calculated. Mutual correlation of examined parameters and correlated relations of these parameters with the climatic conditions during three consecutive years of research was done. The olive fruit parameters significantly depend on the cultivar, year, climate and the fruit ripening index. The dry matter content in Oblica cultivar ranged from 32.0 to 45.6% and the average value was 38.67%, while the dry matter in Leccino ranged from 38.7 to 52.9% with average value of 43.93%. Oil content, when expressed on a dry weight basis, increased in both cultivars with the ripening. The average value of the oil content in Oblica was 41.5% and in Leccino 36.4%. There was a significant positive correlation between the ripening index and the dry matter content and oil content. The dry matter content was positively correlated with the amount of rainfall in the early stages of fruit development. Differences in extractability depending on the harvest time and cultivar were recorded.

Alternate partial root-zone drying (PRD) irrigation is one of the water-saving strategies, while grafting onto some rootstocks is a usefull tool to overcome abiotic stresses in fruit vegetables, including tomato and can enhance macronutrients uptake owing to more vigorous root system. The aim of this study was to investigate the effect of partial root-zone drying on grafted tomato leaf and fruit mineral concentrations (N, P, K, Ca and Mg) and fruit quality attributes. The tomato plants (cv. Clarabella) ungrafted, self-grafted and grafted onto He-man rootstock were soil grown in greenhouse under two irrigation regimes, partial-root zone drying (PRD) and full irrigation (FI). There were no significant differences between treatments in leaf N, P and K concentrations while for leaf Ca and Mg significance were found. Leaves on average had more Ca and Mg under PRD. No differences were found in fruit mineral concentrations between treatments. Fruit soluble solids content (SSC) and titrable acidity were higher under PRD, but tomato juice pH was higher in FI treatment. Also, SSC was affected by grafting type and was highest in ungrafted plants. These results show the effectiveness of PRD with respect to upgrading of fruit quality in tomato without negative influence on grafted tomato leaf and fruit mineral content.

Malaxation (kneading) is the crucial step during olive fruit processing into virgin olive oil (VOO) that exerts a significant influence on the overall quality and final phenolic profile of produced VOO. It also significantly affects oxidative stability of VOO and thus its storage time limit. The effect of three different malaxation times (30, 45, 60 min) were evaluated on the VOO produced by using 100% olives of the Oblica variety at laboratory scale (Abencor mc2). Mixing of olive pastes was monitored at three different temperatures (26, 36, 46oC) for each of three malaxation regimes. The total phenolic content, oxidative stability, antioxidant activity and both chemical and sensory quality parameters were monitored in the fresh VOO and during one-year storage of the oil in sealed bottles stored in the dark at room temperature under the protected atmosphere of inert gas (nitrogen). The best quality parameters (FFA, PV) showed oil samples obtained at 26oC and 30 min. The values of K-numbers were all inside the limits for VOO, except of those oils processed at 46oC (at all three malaxation times). This high malaxation temperature affected the K270 number the most. The oils from Oblica obtained with the shortest kneading time (30 min) and at the lowest temperature had the highest quantity of phenols and a high oxidative stability, compared to the samples produced with a more prolonged kneading at the same temperature. These same olive oils showed also the best sensory properties and harmony between green fruity, bitter and pungent. The unusual exceptions are oils produced at 46oC that all had high levels of total phenols, but in the same time were out of VOO category (regarding K270 numbers).

Poboljšanje kvalitete vina i maslinovog ulja ključno je za financijski uspjeh gospodarskih subjekata. Kvaliteta vina jednako kao i kvaliteta maslinovog ulja povezana je s fiziološkim statusom vinove loze odnosno masline i to prvenstveno sa statusom vode u biljci. Budući da je voda ključni kontrolor fiziološkog statusa biljke, dobro gospodarenje vodom u vinogradu/masliniku može biti korišteno za poboljšanje kvalitete biljaka. To naročito dolazi do izražaja u nasadima gdje vodni stres nastupa brzo. Na mikrolokaciji Donje polje Jadrtovac gdje su suha i vruća ljeta razvoju vodnog stresa u podignutim nasadima vinove loze i masline još dodatno doprinosi izrazito mali kapacitet zadržavanja vode koji je svojstven kultiviranim tlima krša s visokim udjelom skeleta (

The vegetable grafting has received more attention in past years as a sustainable practice for mitigation of abiotic and biotic stresses. The successful management of hydroponic crops assumes minimal use of pesticides and the new approaches for mitigation of pest damage have been tested. The aim of this study was to determine the effect of tomato rootstocks (Arnold, Buffon, Emperador and Maxifort) on incidence of tobacco whitefly Bemisia tabaci (Gennadius) in hydroponic tomato crop. Cultivar Clarabella was used as a scion, and the control was non-grafted Clarabella or grafted on its own roots. The plants were artificially infested with adult instars of B. tabaci at 20 October 2015. Population density of large nymphs (4th instar to pupae) was assessed on 4th, 5th and 6th leaf, 37 days after infestation. Number of individuals was counted and expressed per cm2. Leaf anatomy characteristics (the thickness of the lamina, adaxial and abaxial epidermis and leaf mesophyll) of all treatments were measured. The large nymphs population density of B. tabaci was lower in tomato plants grafted onto different rootstocks, compared to non-grafted Clarabella plants, or grafted on its own roots regardless of leaf position. Total leaf thickness was the highest in non-grafted cv. Clarabella plants compared to plants grafted on tested rootstocks or on its own roots. Non-grafted plants of cv. Clarabella, that were more attractive to the pests, were characterized by the 12.1 μm thickness of lower epidermis and 145.2 μm thickness of mesophyll. It seems that reduction of B. tabaci density on leaves of grafted plants could be at least partially connected to changes in leaf anatomy induced by rootstock. The results can be applied in an integrated tomato protection against B. tabaci.

Multielemental analysis of olive oil can be important tool in evaluation of its geographical traceability, as the elemental composition of soil is reflected in olives and in olive oil. However, whereas determination of elements in soil is an easy task, it is not a case for olive oil, as only minor fraction of elements are transferred to the oil, and concentrations of trace elements are usually very low. In addition, in order to get a fingerprint of elements from different geographic regions, it is necessary to determine as much elements as possible. An ideal instrumental technique to achieve this goal is inductively coupled plasma mass spectrometry technique (ICPMS), which enable multielemental analysis and very low detection limits. In this work development of the method for determination of total concentration of number of elements (major elements, trace elements and rare earth elements) based on microwave digestion and detection with high resolution inductively coupled plasma mass spectrometry technique (HR- ICP-MS) will be presented. In order to develop the method for quantitative determination of the multielement composition of olive oil, samples of virgin olive oil from the Croatian Adriatic coast, were digested with various mixtures of nitric acid and hydrogen peroxide, chosen according to existing literature. In the absence of certified reference material for elements determination in oils, recovery experiments with addition of multielement standard solution prepared in oil were used to define optimal digestion procedure. In the literature, ultrasonic assisted extraction of metals from olive oil by a mixture of diluted minerals acids (usually nitric and hydrochloric acids) was also used for determination of their multielemental composition and geographic traceability. In order to be able to compare data obtained for Croatian olive oils with olive oils from other regions, which were analyzed with ultrasonic extraction, two analytical methods were compared for the whole set of measured elements.

As a typical component of the Mediterranean diet, virgin olive oil is consumed unrefined and it is rich in important molecules, such as minor polar compounds (hydroxytyrosol, tyrosol, secoiridoids and flavonoids) and fatty acids. These molecules not only influence the sensorial properties of both olives and virgin olive oil but they are also important markers for typicity, biodiversity and quality determination of this product. The aim of this study was to evaluate the minor polar compound and fatty acid contents of monocultivar virgin olive oils, typical in Dalmatia olive region, in order to have better knowledge about the quali-quantitative profiles of these compounds in samples obtained from both the same collecting season and same processing technique. Quali-quantitative analysis (performed by HPLC/DAD and GC) could be a useful tool to better correlate the typicity of the virgin olive oil with its minor polar compound and fatty acid pattern. The results showed that within the germplasm studied a great variation was present both in fatty acid and phenols composition related to genetic origin. The sensorial assessment was also performed on the investigated olive oil samples in order to define their sensorial profiles regarding cultivar. Further studies are in progress to isolate the specific aroma compounds in order to investigate their impact to biological, nutritive and sensorial properties of these oils.

Effect of malaxation time and temperature on Levantinka virgin olive oil (VOO) properties during production process was studied. Mixing of olive pastes was performed at 26, 36, 46oC. Also, for every temperature effect, malaxation time was studied during 30, 45, 60 min. In order to estimate the olive oil quality the investigation of free fatty acid, peroxide value, UV spectrophotometric indices, total phenols content, sensory evaluation, oxidative stability and antioxidant activity was carried out. It’s evident that both, malaxation time and temperature, affect the properties and quality of olive oil obtained. The lowest peroxide value, the highest total phenols content and DPPH value was achieved at 36oC and 30 min. The lowest free fatty acid and the highest oxidative stability was also achieved at the same temperature (36oC) but at some longer malaxation time (FFA 60 min, Rancimat test 45 min). The values of K-numbers were within the limits for VOO for all samples processed at 26oC and 36oC and 30 and 45 min, respectively. Sensory analyses of investigated oils showed the highest score for those processed at same malaxation conditions as for K-numbers. The highest bitterness was perceived in samples obtained at 36oC and 30 min of malaxation time while pungency in samples produced at 36oC and 60 min of malaxation time.

Površine privedene poljoprivrednoj proizvodnji melioracijskim zahvatima nepoznatih su pedoloških značajki. Količina sitnice, kao i kapaciteti tla za vodu i hranjiva, obično su neistraženi te se gospodarenje vodama i hranjivima na održivi način ne može provoditi. Osigurati dostatne količine vode za navodnjavanje poljoprivrednih kultura te održivo gospodarenje vodom i hranjivima na takvim površinama je znanstveno stručni izazov. Jedno od otvorenih pitanja je i utjecaj navodnjavanja na rast i razvoj primjerice vinove loze te na kvalitetu grožđa i vina proizvedenih u uvjetima navodnjavanja. Slična situacija je i s maslinama i kvalitetom maslinovog ulja. Na temelju navedenih polazišta i opisa problema u projektnom zadatku su definirani sljedeći ciljevi: 1. Odabrati stabilan izvor vode za navodnjavanje i uniformne lokacije za provedbu istraživanja, te nabaviti opremu za mjerenje klimatskih parametara ; 2. vlage u tlu, potencijala vode u listu kao i sustave za navodnjavanje ; 3. Postaviti poljski pokus ; 4. Odrediti značajke tla na pokusnom polju Jadrtovac ; Odrediti potrošnju vode ; 5. Odrediti intenzitet fotosinteze vinove loze, potencijal vode u listu vinove loze te mineralni sastav lišća vinove loze ; 6. Provesti ampelografska istraživanja, uvometriju i mehaničku analizu grozda i bobice ; 7. Odrediti prinos i bujnost vinove loze te pratiti dozrijevanje grožđa ; 8. Odrediti kemijski sastav mošta, analizirati organske, aminokiseline i polifenole ; 9. Provesti mikrovinifikaciju i analizu vina ; 10. Izvršiti morfološka mjerenja na stablima masline te folijarnu analizu masline.

Cilj ovog istraživanja bio je odrediti udio bioaktivnih komponenata, senzorske karakteristike i oksidacijsku stabilnost djevičanskih maslinovih ulja autohtone sorte oblice i sorte leccino uzgajanih na području srednje Dalmacije. Ispitane su promjene sastava i svojstava u uljima koje nastaju pod utjecajem okolišnih čimbenika, stupnja zrelosti plodova maslina te postupka filtracije. Cilj rada također je bio i utvrditi genetičke profile ispitivanih sortnih djevičanskih maslinovih ulja te procijeniti mogućnost sljedivosti djevičanskog maslinovog ulja pomoću mikrosatelitnih biljega.

Environmental factors such as light, temperature and quantity of available water affects the biosynthesis of phenolic compounds and fatty acids of virgin olive oils, their mutual content and ratios which have an affect on the final product quality and stability. The influence of seasonal weather fluctuation, in term of air temperature and rainfall, on the phenolic content and fatty acid composition was investigated in 'Oblica’ and 'Leccino' virgin olive oils grown in Dalmatia, Croatia. Specified parameters have shown to be significantly influenced by climate conditions. The oleic fatty acid was negatively correlated, while the palmitic, linoleic and linolenic fatty acids were positively correlated with average daily air temperatures in the period of intensive growth and ripening of olives. The content of total phenolic compounds in the Oblica and Leccino virgin olive oils was significantly different depending on the year of cultivation, although the cultivars showed different behavior with regard to climatic parameters during the year. In the Oblica virgin olive oils highest average content of phenolic compounds was recorded in driest year, while in the Leccino oils highest values were in the year with most rainfall. No correlations between the content of phenolic compounds in oils and rainfalls in July and August were recorded, while negative correlation was observed with the content of phenolic compounds and the amount of rain in September.

Cilj je bio podizanje konkurentnosti i prepoznatljivosti autohtonih češnjaka jadranskog područja isticanjem kvalitete i povećanjem proizvodnih površina pogodnih za proizvodnju ove kulture, to jest definiranjem područja proizvodnje i mogućnosti proširenja proizvodnje na područja sličnih pedoklimatskih uvjeta te ih prikazati na pedološkoj karti. Istraživanja su provedena na pokušalištu Instituta za jadranske kulture te na tipičnim lokacijama za proizvodnju češnjaka (Dalmatinska zagora). Utvrdila su se morfološka svojstva prikupljenih jadranskih ekotipova češnjaka kao i kvalitativna svojstva lukovica (mineralni sastav, količina suhe tvari, udio fenolnih spojeva i postotak ulja), koja su uspoređena s češnjakom uvozenim iz Kine. Također, utvrđena je osjetljivost istraživanih češnjaka na štetočinje kao i održivost lukovice (domaćih i introduciranih genotipova) tijekom čuvanja (skladištenja).

Sensory analysis of virgin olive oil (VOO) is a final step of olive oil quality evaluation. Today there are modern analytical methods that can identify and quantify both volatile and non-volatile substances that are the main reason for specific taste, smell and aroma of VOO. However, they can not give complete information about the smell and taste because they can not provide a display interaction between taste and odors that can be perceived by the human senses. Therefore, the sensory analysis is still the most effective way to identify the difference, the quality and quantity of sensory characteristics of olive oil.This paper presents and illustrates the method for the organoleptic assessment of VOO. The positive and negative sensory properties of VOOs are described as well as the main causes for their occurrence in certain olive oil sample. For positive aroma attributes of VOOs are largely responsible volatile substances generated after breaking the structure cells in the process of milling olives and olive mixing olive paste during a series of enzymatic reactions known as lipoxygenase time, and smelling undesirable properties resulting from errors and omissions in the fruit protection, fruit storage before processing, processing of fruits and storage of produced oil.Phenolic compounds, natural antioxidants present in VOO, are responsible for positive taste attribute (bitterness) and also for kinesthetic properties (bitterness and pungency) of VOO. The amount of phenolics in VOO is related to the health beneficial effects that make VOO a very valuable and appreciated commodity. The level of phenols is a very important parameter in the VOO quality evaluation since it’s strictly related both to the oil’s resistance to oxidation because of their antioxidative properties. As an example here we present the results of descriptive sensory analyses of typical croatian monovarietal VOOs and their total phenolic content.

Cilj istraživanja bio je odrediti teške metale i sastav masnih kiselina 27 ekotipova češnjaka prikupljenih s 21 različite lokacije u sjeverno-istočnom dijelu Jadranske regije. Sadržaj suhe tvari lukovice češnjaka ekotipova Brgud, Konavle, Kurtovići, Ljubitovica, Primorski Dolac (proljetni), Rastok i Vojnić bio je veći od 40%. Najmanja koncentracija Cu zabilježena je kod ekotipa Polača Knin (0, 72 g/kg svježe tvari ; ST), dok je najveća zabilježena kod Opuzen ozimi (4, 34 g/kg ST). Najveći sadržaj Zn zabilježen je kod Opuzen proljetni (23, 1 g/kg ST), dok je najniža koncentracija (6, 9 g/kg SM) zabilježena kod ekotipova Golubić i Kurtovići. Najmanja koncentracija Cd zabilježena je kod ekotipa Ljubitovica bijeli i Trnbusi 3 proljetni (0, 06 i 0, 09 g/kg ST). U lukovicama češnjaka s lokacija Rastok, Vojnić i Konavle je zabilježena najveća koncentracija Cd (0, 44, 0, 41 i 0, 39 g/kg ST). Ukupne masne kiseline u lukovici češnjaka bile su od 29, 1 do 69, 4 mg/kg suhe tvari. Omjer linoleinska/alpha-linoleinska kiselina se smatra važnim čimbenikom u prehrani. Hrvatski ekotipovi češnjaka pokazuju veliku varijabilnost te je na lokacijama Brgud, Kričke, Golubić 1 i 2 zabilježen najmanji omjer linoleinske/alphalinoleinske kiseline (5, 74, 5, 79, 5, 81 i 5, 88). Studija je pokazala kako testirani ekotipovi češnjaka imaju visok sadržaj nutritivno važnih komponenti, kao što su masne kiseline te da su sve komponente kvalitete pod značajnim utjecajem genotipa i lokacije uzgoja.

Garlic (Allium sativum L.) is an important ingredient of the diet of many populations and there is long-held belief in health enhancing properties. The chemical composition of garlic bulbs can be influenced by ecotype, growing location and cultivation factors. The aim of this study was to determine the quality components in six garlic ecotypes, collected in northeast Adriatic region. Samples were collected from six different locations: Brgud, Konavle, Kričke, Ljubitovica, Opuzen and Trnbusi. Total polyphenols and antioxidant activity of garlic ecotypes were evaluated using Folin-Ciocalteau and 2, 2–diphenyl-1-pirydrazyl method. Besides, ecotypes influence on fatty acid composition was also investigated by gas chromatography. Ecotypes Brgud, Konavle and Ljubitovica had garlic bulbs contained more than 40% of dry weight (DW) while significantly lower bulb DW was recorded in samples from Kričke, Trnbusi 2 and Opuzen Ozimi (37.4 ; 36.0 and 35.8% DW). The amount of total phenols varied widely and ranged from 86.65 to 227.29mgGAE/g DW. Garlic bulbs contained 42.1 to 69.4 mg/kg DW total fatty acids. In all ecotypes, linoleic acid, essential fatty acid, was predominant in amount of average 58%. Ecotype Ljubitovački (56.37) had the lowest and Opuzen Ozimi had the highest (60.70%) content of linoleic acid. Ecotype significantly affected content of palmitic, oleic and linolenic acid while no statistically differences were found between investigated ecotypes in the stearic acid content. All samples exhibited some radical scavenging activity and positive correlations between total polyphenol content and antioxidant activity was found. The study showed that all evaluated garlic samples had high levels of nutritionally important components and thus might be a rich source of antioxidants beneficial to human health.

Extra virgin olive oil is produced by mechanical and physical processes and therefore it keeps all valuable bioactive and aroma compounds. Fresh produced olive oil is always turbid and it has influence on the consumer’s choice. Filtration has recently imposes as last step in product finalization. During filtration, quantitative and qualitative changes take place, especially on minor components. The influence of filtration on phenolic content, α-tocopherol, oxidative stability and sensory attributes (oil aroma) of Oblica and Leccino olive oils were studied. Filtered oils of both investigated oils show a significant decrease on the total phenol content. In Oblica oil filtration had no effect on α-tocopherol content while in Leccino higher content of α-tocopherol was detected in unfiltered oil. After the filtration in both studied oils, oxidative stability loss was recorded of more than 14%. The filtration effect on oil aroma was evaluated by a panel tasters and sensory evaluation showed no significant influence on the sensory scores.

Chemical composition of garlic bulbs is influenced by genotype, agronomic, technological, and environmental factors. The aim of this study was to determine the mineral and fatty acid composition of garlic bulbs of 27 ecotypes collected in northeast Adriatic region (Croatia). Samples were collected from 21 different locations: Brgud, Golubic, Jezero, Konavle, Kricke, Kurtovici, Ljubitovica, Metajna Pag, Metkovic, Miljevci, Obrovac Sinj, Opuzen, Polaca Knin, Primorski Dolac, Rastok, Stilja, Tinjan, Trnbusi, Vojnic and Zmijavci. Ecotypes Brgud, Konavle, Kurtovici, Ljubitovica (samples Bijeli and Sarac), Primorski Dolac (sample spring), and Rastok and Vojnic had garlic bulbs with more than 40% of dry matter. The lowest bulb dry weight (less than 34.8%) was recorded in samples from Golubic (samples 1 and 2), Metajna, Polaca Knin and Primorski Dolac (sample winter). The highest bulb N concentration (41.3 g/kg DW) was recorded on location Metajna, while the lowest was on location Miljevci (13.1 g/kg DW). At the same location was recorded the lowest bulb P concentration (4.13 g/kg DW), while the highest was observed in both samples from Opuzen (6.49 and 6.53 g/kg DW). Highest bulb K concentration was recorded on sample Trnbusi 4 winter (15.3 g/kg DW), while the lowest on Brgud (7.3 g/kg DW). Lowest bulb Cu concentration was recorded on Polaca Knin (0.72 g/kg FW), whereas highest on sample Opuzen winter (4.34 g/kg FW). Highest bulb Zn concentration was recorded on sample Opuzen spring (23.1 g/kg FW), while lowest concentrations (6.9 g/kg FW) were found in Golubic and Kurtovici. Lowest bulb Cd concentrations were found in ecotypes Ljubitovica White and Trnbusi 3 spring (0.06 and 0.09 g/kg FW). At locations Rastok (0.44 g/kg FW), Kozica-Vojnic (0.41 g/kg FW) and Konavle (0.39 g/kg FW) were found the highest Cd concentration in the garlic bulb. Garlic bulbs contained from 29.1 to 69.4 mg/kg DW total fatty acids. Linoleic/alpha-linolenic acid ratio is considered an important dietary factor, and an alpha-linolenic acid-rich Mediterranean diet is recommended. Croatian garlic ecotypes showed great variability, with locations Brgud (5.74), Kricke (5.79) and Golubic 1 and 2 (5.81 ; 5.88) having the lowest linoleic/alpha-linoleic acid ratios and location Obrovac Sinj the highest (9.46). The study revealed that garlic bulbs had high levels of nutritionally important components, such as fatty acids and minerals, and that all quality components were strongly influenced by genotype and location.

U mediteranskom dijelu Republike Hrvatske najveća proizvodnja trešnje nalazi se u Splitsko-dalmatinskoj županiji s glavnim centrima na području Kaštela i Poljica (Omiško zaleđe). U navedenim područjima veći je broj autohtonih kultivara koje se sve više istiskuju iz proizvodnje te im prijeti potpuni gubitak pod utjecajem novih gospodarski interesantnijih introduciranih kultivara. Cilj ovog istraživanja bio je prikupiti i evaluirati autohtone kultivare te procijeniti njihov gospodarski značaj. Na temelju fenoloških opažanja i komunikacije s proizvođačima izdvojeno je 12 genotipova. Morfološka, pomološka i kemijska karakterizacija provedena je temeljem UPOV deskriptora.

The scientific work on the authenticity and quality of olive oil is an ever-growing area. In the last decade great attention has been focused on characterization of monovarietal virgin olive oils in order to protect and preserve olive biodiversity in major olive growing countries, as well as in Croatia. Virgin olive oil (VOO) contains about 98% neutral lipids, mainly triglycerides (96-97%), a small quantity of diglycerides (1-2%) and a variable quantity of free fatty acids, which are used as a marker of oil quality. The object of this study is to explore the possibilities of different chemical parameters, normally determined in olive oil analysis, to differentiate and classify olive oil samples of different origin, in order to confirm the authenticity of Levantinka VOOs, one of the most common autochthonous olive cultivar in the Dalmatia region. The paper describes characteristics of virgin olive oils coming from three different geographic origins, i.e. Kaštela, island Korčula and island Brač. Main chemical quality parameters were evaluated (free fatty acids, peroxide value and UV-spectrophotometric oxidation indexes (K232 and K270), as well as analyses of fatty acid and triglyceride composition, as one of authenticity parameters of olive oil were also evaluated according to international analytical methods. Some of the most important relationships of fatty acids in olive oil are described, by which it essentially differs from other vegetable oils (proportion of oleic and linoleic).