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In the Mediterranean basin, the treatment and disposal of olive mill pomace (OMP) remain a salient environmental issue for the olive oil- producing industry. This study assesses the effects of olive-processing technology (three- phase and two-phase systems) on the potential use of OMP as a soil amendment. Samples from 12 Croatian olive mills were analysed for their total phenolic content (TPC), residual oil fraction, and elemental concentration. The samples were profiled using FT-IR spectroscopy and structurally characterised using SEM-EDS. Compared to three- phase samples, two-phase OMP was more acidic (pH 4.5 vs pH 5.0), with a higher TPC (3835 vs 1576 mg/kg f.w.), oil content (11.7 vs 7.5 % d.w.), EC (5.1 vs 3.0 mS/cm), and levels of Ca (1.34 vs 1.20 g/kg d.w.) and Cu (10.4 vs 7.0 mg/kg d.w.). Similar values of C/N (61 vs 72), N (10 vs 8.1 g/kg d.w.), P (1040 vs 691 mg/kg d.w.), and K (13.7 vs 8.1 g/kg d.w.) were observed. The amounts of Cr, Cu, Ni, and Zn were below EC limits in both cases. The EDS mapping revealed that Ca was concentrated at sharp-edged OMP particles while K was evenly distributed, suggesting that pelletized OMP compost is preferable for amending soil to obtain a homogeneous distribution of nutrients. It was also possible to distinguish between OMPs based on oil and lignin absorption bands in their FT-IR spectra. According to the obtained results, composting is recommended for both types of OMP to produce a safe product for amendment purposes.

The potential effect of pre-inoculation of processing tomato (Solanum lycopersicum L.) plants with arbuscular mycorrhizal fungi (AMF) on yield and fruit properties was investigated in conventional production. Tomato seeds were sown in seedling trays filled with a substrate non-inoculated (AMF-) or inoculated (AMF+) by selected mycorrhizal strains. Seedlings were transplanted in Terra rossa soil and grown in conditions with mineral fertilization and irrigation. Tomato fruits were sampled at harvest. Tomato plants under both treatments had high levels of mycorrhizal colonization, due to applied inoculum (AMF+) or indigenous (AMF-) inoculum present in the soil. Applied AMF+ treatment increased P and decreased K content in tomato fruits. Content of trace elements such as As and V significantly increased, while Pb content significantly decreased in the fruits of AMF+ when compared to the AMF- treatment. No significant effect of AMF+ treatment was observed on yield, fruit quality (soluble solids, pH, total acidity, fruit firmness), lycopene and antioxidant activity of tomato fruits. The overall results suggest that processing tomato is highly susceptible to the indigenous AMF, while seedlings inoculation with selected AMF improves only total phenolic and P fruit content. This means that AMF have a potential application in commercial processing tomato production, however a targeted adaptation of management decissions is required for more extensive results.

Olive oil is considered one of the most valuable vegetable oils and is highly appreciated by consumers for its specific and distinguishable taste and aroma, as well as its nutritional value. Sterols and triterpene diols are important carriers of bioactive properties of olive oil and are responsible for some of the beneficial effects of its consumption on human health, such as lowering serum LDL-cholesterol levels and significantly reducing the risk of cardiovascular diseases. The concentration of total sterols and the proportions of particular sterols and triterpene diols are among the parameters used to verify and prove the authenticity of olive oil in accordance with the EU and other countries’ regulations. Finally, their composition has been shown to have high discrimination potential for ensuring traceability with respect to variety, geographical origin, harvest date, and other factors. For these reasons, the research on sterols and triterpene diols in olive oil is an ever-growing field of scientific interest with great practical importance. This review focuses on all the important aspects of sterols and triterpene diols in olive oil, from their chemical structure, biosynthesis, occurrence and role in plants, health benefits, and their use in official controls of olive oil purity and authenticity, to a conclusive survey on the recent findings about the effects of different factors of influence on their content and composition, with a detailed comparative analysis of studies that investigated the effects of the two most important factors, variety and ripening degree.

The effects of different fertilisation treatments with arbuscular mycorrhizal fungi (AMF) inoculation on AMF root colonisation, fruit yield, nutrient and total phenol contents, volatile compound composition, and sensory attributes of tomato (Solanum lycopersicum L.) were investigated. Mineral, organic, and mineral + organic fertiliser application positively affected tomato yield (35%–50%) and phosphorus concentration (24%–29%) compared with controls. AMF application had a significant impact on the total nitrogen (+9%), manganese (+12%), and hydrophilic phenol (+8%) contents in the fruit. Volatile compounds were affected by the interactive effects of fertilisation and AMF application. The response of tomato fruit sensory quality indicators was relatively modest, with only a few sensory characteristics affected to a lesser extent. Although tomato showed susceptibility to field-native AMF, particular combinations of fertilisation and AMF inoculation were more effective at improving the quality parameters of tomatoes under field conditions applied in this study.

The interactive effects of cultivar, collecting period, and geographical location on the content and composition of biophenols and macro and micronutrients in olive (Olea europaea L.) leaf were investigated. Leaves of six cultivars were collected at three periods in two locations in Croatia. The leaves of Istarska bjelica cultivar had the greatest biophenol (oleuropein) potential, especially those sampled in January and in March at the location of Pag. All the cultivars yielded leaves with the highest concentration of biophenols in March, which coincided with the pruning period. Except for high oleuropein concentration in Istarska bjelica, flavonoids were found to be most useful for differentiating olive leaves according to cultivar. Verbascoside turned out to be the most potent differentiator of collecting periods, while phosphorus and zinc turned out to be most useful for differentiating locations. Despite different agroecological conditions at the two locations, cultivar exhibited a significant effect on olive leaf nutrient composition, which was certainly causally related to that of the biophenols. The results obtained showed that it is possible to plan more well-timed and efficient exploitation of biophenols from olive leaf based on the knowledge about the interactive effects of the three studied factors.

With the aim to investigate the influence of post-harvest olive fruit storage temperatures on virgin olive oil production parameters, composition and quality, Istarska bjelica (IB) and Rosinjola (RO) fruits were stored for seven days at room temperature (RT), +4 &deg, C and &minus, 20 &deg, C prior to oil production. Lower temperatures delayed post-harvest maturation of IB fruits. Theoretical oil content did not change depending on the storage temperature, while the highest oil yield and extractability index were obtained after storage at RT. Chlorophylls decreased in IB-RT and in IB-20. A decrease in the sensory quality of oils was detected after fruit storage at RT and &minus, C, while the refrigeration temperature of +4 &deg, C preserved it. Regarding the content of fatty acid ethyl esters, an increase was observed in IB-RT oils. Storage at RT increased the content of waxes, while the lower temperatures partially suppressed this phenomenon. In oils of both cultivars, storage at +4 &deg, C preserved the concentration of most phenolic compounds at a level more similar to that of the fresh oil when compared to the other two treatments. In the production conditions, when prolonged fruit storage is necessary, refrigeration seems to be the most suitable option.

Naplata putarine na autoputevima predstavlja mehanizam za finansiranje izgradnje putne infrastrukture, njenu eksploataciju i održavanje. Cilj ovog rada je da se izvrsi analiza stavova korisnika o naplati putarine na autoputevima Srbije. U tu svrhu je definisana anketa koja je sadržala kako pitanja o socio-ekonomskim karakteristikama korisnika, tako i pitanja o naplati putarine. Anketa je sprovedena elektronskim putem i uzorak je cinilo 680 ispitanika. Za obradu podataka koriscene su metode deskriptivne statistike. Dobijeni rezultati ce pomoci donosiocima odluka prilikom definisanja strategije naplate putarine, koja bi trebala da doprinese unapređenju postojeceg sistema naplate putarine u Srbiji.

The aim of this study was to compare quality changes and compositional characteristics (fatty acids, total phenols, sensory profile) during 12 months storage of Buža and Istarska bjelica cv. virgin olive oils clarified by filtration at an industrial scale (filter press equipped with cellulose filters) and those clarified by natural sedimentation and decantation, as well as the influence of filtration of virgin olive oils on sterols and triterpene dialcohols composition. There were no significant differences in hydrolytic deterioration and sensory scores during the whole storage period between filtered and naturally sedimented oil samples. After 6 months, natural sedimentation was more favorable as regards delaying of oxidative deterioration, while filtration provided a more stable sensory profile. As regards total phenols the impact of the clarifying procedure was dependent on cultivar and fruit ripeness degree and it was more emphasized than the impact of storage. Filtration slightly affected the fatty acids composition, but natural sedimentation and decantation had no effect on it. Nevertheless, filtration did not compromise the confirmation of virgin olive oil authenticity according to the fatty acid composition, as well as according to sterols and triterpene dialcohols.

The interactive effects of ripening degree, malaxation duration and temperature on Oblica cv. (Olea europaea L.) virgin olive oil phenols, volatiles, and sensory quality were investigated. Olives were picked at three ripening degrees with International Olive Council indices of 0.68, 2.48 and 4.10, and processed by malaxation at 22 and 30 °C, and at both temperatures for 30 and 60 min. Ripening exhibited the strongest effect, and malaxation duration the weakest. Phenols were generally found to decrease during ripening; however 3,4-DHPEA-EDA and p-HPEA-EDA increased. Similar behaviour was observed for (E)-2-hexenal. Higher malaxation temperature induced an increase in particular important phenols and C6 alcohols, while C6 aldehydes mostly decreased. Interactions between the factors were established, mostly between ripening degree and malaxation temperature: the effect of the latter was most pronounced for ripe olives, especially for 3,4-DHPEA-EDA, p-HPEA-EDA and C6 volatiles. Sensory attributes were generally in agreement with the chemical composition.

Despite having an interesting native olive gene pool and a rapidly emerging olive oil industry, monovarietal extra virgin olive oils (EVOO) from Croatia are relatively unexplored. To investigate the inter-varietal diversity of typical volatile and phenolic profiles of Croatian EVOO, 93 samples from six olive (Olea europaea L.) varieties were subjected to gas chromatography-ion trap mass spectrometry (GC-IT-MS) and ultra-performance liquid chromatography with diode array detection (UPLC-DAD), respectively. Quantitative descriptive sensory analysis was also performed. Analysis of variance extracted many relevant exclusive or partial discriminators between monovarietal EVOOs among the identified volatile compounds and phenols. Successful differentiation model with a 100% correct classification was built by linear discriminant analysis, while the most typical volatiles for each monovarietal EVOO were confirmed by partial least squares discriminant analysis. Diverse typical sensory attributes among the EVOOs were tentatively ascribed to the variations in the composition of volatiles and phenols. It was proven that the approach that comprises GC-IT-MS and UPLC-DAD analysis may provide additional objective information about varietal origin and typicity which successfully complement those obtained by sensory analysis. The approach was characterized as universal in nature, with a significant potential to contribute in strengthening the varietal identities and position on the market of monovarietal and Protected Denomination of Origin (PDO) EVOO.

U ovom je radu ispitan utjecaj filtracije svježih sortnih djevičanskih maslinovih ulja Buže i Istarske bjelice u industrijskom mjerilu na sastav hlapljivih tvari, ukupnih fenola te senzorska svojstva, a uzorci ulja izbistreni filtracijom uspoređeni su s onima koji su izbistreni prirodnom sedimentacijom/dekantacijom nakon šest mjeseci skladištenja. Filtracija je različito utjecala na sastav hlapljivih tvari uzoraka ulja dobivenih od različitih sorata. U ulju sorte Buža je nakon filtracije lagano porastao samo udjel (Z)-2-pentenola, dok se u ulju Istarske bjelice promijenio udjel osam spojeva nakon filtracije (udjeli heksanala, (E)-2-pentenala, (Z)-3-heksenala, (Z)-2-pentenola i (Z)-3-heksen-1-ola su porasli, dok su se udjeli heksil acetata, (E)-2-penten-1-ola i (E)-2-heksen-1-ola smanjili). U svježe filtriranom ulju sorte Buža opaženo je blago smanjenje udjela ukupnih fenola, dok je u ulju sorte Istarska bjelica to smanjenje bilo izraženo, što je uzrokovalo smanjenje intenziteta pikantnosti i gorčine ulja. Sedimentacija/dekantiranje imali su prednost naspram filtracije kod obje sorte, jer su očuvali senzorski profil i udjel ukupnih fenola. Profili arome procijenjeni na osnovi vrijednosti aktivnosti mirisa hlapljivih spojeva i njihovog grupiranja u serije uspoređeni su sa stvarnim senzorskim profilima maslinovih ulja. Dobiveni rezultati mogu imati veliku primjenu u industriji maslinovih ulja tijekom optimiranja tehnologije proizvodnje sortnih djevičanskih maslinovih ulja s očuvanim specifičnim i tipičnim senzorskim svojstvima, ali mogu poslužiti i stručnjacima za izbor metode bistrenja djevičanskih maslinovih ulja prije analize hlapljivih tvari., This study investigates the effect of industrial scale filtration of fresh monovarietal virgin olive oil from Buža and Istarska bjelica cultivars on their volatiles, total phenols and sensory characteristics, and compares the oil samples clarified by filtration with those clarified by natural sedimentation/decantation after six months of storage. Filtration had a different effect on volatiles from the oil samples obtained from different cultivars. In the oil from Buža cultivar immediately after filtration only the amount of (Z)-2-pentenol slightly increased, but in Istarska bjelica the oil filtration affected eight compounds (the amount of hexanal, (E)-2-pentenal, (Z)-3-hexenal, (Z)-2-pentenol and (Z)-3-hexen-1-ol increased, while of hexyl acetate, (E)-2-penten-1-ol and (E)-2-hexen-1-ol decreased). In fresh filtered oil from Buža cultivar a slight decrease of total phenols was observed, while in those from Istarska bjelica the decrease was sharp, causing a decrease in the pungency and bitterness. Sedimentation/decantation had advantages over oil filtration of both cultivars, due to improved effect on the preservation of the sensory profile and the level of total phenols. Tentative aroma profiles based on odorant series obtained from the odour activity values were compared to the actual olive oil sensory profiles. These results could have a high level of applications in the olive oil industry for the optimization of the technology for obtaining monovarietal virgin olive oil with preserved specific and typical sensory characteristics, but also may serve experts to choose an appropriate virgin olive oil clarification method prior to analysis of volatile compounds.

The aim of this study was to characterize monovarietal olive oils obtained from two less known autochthonous cultivars (Bova and Buža puntoža) on the basis of sterols, triterpene dialcohols and fatty acids profile for the first time, and three monovarietal olive oils obtained from the most widespread autochthonous cultivars (Buža, Istarska bjelica and Rosinjola) grown in Istria, Croatia. β-sitosterol, Δ-5-avenasterol and campesterol were the most abundant sterols in all samples. Campesterol, β-sitosterol and Δ-5-avenasterol most significantly differentiated investigated oils. Bova oil had the highest amount of total sterols (2964 ± 458 mg/kg). Istarska bjelica oil had a peculiar sterol composition with exceptionally low β-sitosterol (67%), high Δ-5-avenasterol (27%) and the highest triterpene dialcohols percentages. Rosinjola and Istarska bjelica oils had the highest monounsaturated fatty acids level, Buža oil had the highest polyunsaturated fatty acids level, while Bova oil showed the highest level of saturated fatty acids. Tested oils obtained from the most abundant cultivars fulfilled all the demands of the current EU regulation required for virgin olive oil regarding sterols, triterpene dialcohols and fatty acids, but Bova and Buža puntoža oil slightly exceeded the upper limit for linolenic acid. Since cultivar is the source of natural variation of sterols, triterpene dialcohols and fatty acids in virgin olive oils, the knowledge about the content of these particular compounds in different monovarietal oils from autochthonous cultivars is important to determine possible disagreements with the demands of the current legislation required for virgin olive oils, in order to anticipate possible false results indicating adulteration.

To investigate if the anecdotal varietal typicity concepts for two monovarietal virgin olive oils (VOO) can be scientifically supported and explained, VOO samples were sorted according to typicity grade and related to sensory and compositional data for volatiles and phenols. Clear inter-varietal, as well as intra-varietal boundaries between more and less typical samples were established by univariate and multivariate statistics. A variety-typical complex odor was related to a complex VOO volatile composition with relatively high amounts of lipoxygenase-derived compounds, accompanied by hydrocarbons, terpenes, and benzenoids. A simpler odor, described mostly as green and typical for the other monovarietal VOO, coincided with the lower amounts of the same volatiles. The intensity of bitterness and pungency was mostly in correlation with the amount of major phenols. Two monovarietal VOOs were clearly distinguished with respect to their variety-typical expression of pungency: the one described as gradually increasing was tentatively related to pinoresinol, while the other, described as immediately strong and burning, was assumed to originate mainly from p-HPEA-EDA. Intra-varietal typicity grades correlated with hedonic liking, as well as with general VOO positive sensory attributes related to key volatiles and phenols.

Despite their importance as bioactive compounds and authentication parameters in olive oil, the response of policosanol aliphatic alcohols to even the most influential sources of variability is practically unknown. To investigate policosanol variation in olive oil as a result of variety, ripening, and oil storage temperature, 36 samples were subjected to gas chromatographic (GC-FID) and mass spectrometric (GC-MS) analysis, and results were processed by univariate (ANOVA) and multivariate (SLDA) statistics. The concentration (mg/100 g) and relative amount (%) of pentacosanol accounted for the most variation due to variety. The largest influence of ripening was observed for pentacosanol (%) and docosanol (%). Docosanol, tricosanol, and tetracosanol amounts mostly increased during ripening, whereas those of pentacosanol, hexacosanol, heptacosanol, and octacosanol decreased in Črna and Rosinjola oils, whereas Buža showed different patterns in some cases. Variations as a result of storage were lower and inconsistent. Results suggest that the investigated olive oils retained the bulk of their health beneficial features of policosanol origin throughout shelf-life. Relatively successful differentiation of oils achieved by multivariate models pointed to the potential use of policosanol alcohols as chemical indicators of varietal origin which are independent on ripening degree, and vice versa, applicable both for fresh and stored oils.

Sterols and triterpene diols in olive oil as indicators of variety and degree of ripening derived from three olive varieties and produced at three different harvesting periods were studied. In order to test the stability of the proposed indicators, oils obtained were stored for 12 months at three different temperatures. Thirty-six samples in total were subjected to GC analysis and results were processed by multivariate chemometric methods (MANOVA, PCA, and SLDA). Campesterol, β-sitosterol, Δ(7)-campesterol/Δ(5,24)-stigmastadienol, clerosterol, uvaol, and campestanol/Δ(7)-avenasterol were established as the indicators of variety of fresh oils, while when stored oils were included in the model, the final three compounds were substituted by 24-methylene-cholesterol/stigmasterol. The most important variables for differentiating fresh oils according to degree of ripening were Δ(7)-campesterol/β-sitosterol, uvaol/stigmasterol, clerosterol/Δ(5)-avenasterol and sitostanol/uvaol, while stored oils were differentiated by campestanol/stigmasterol, erythrodiol, stigmasterol/Δ(7)-campesterol, Δ(5)-avenasterol, 24-methylene-cholesterol/β-sitosterol and 24-methylene-cholesterol. Results demonstrated that sterols and triterpene diols can be used as indicators of variety and degree of ripening among virgin olive oils.

To investigate the variability of 4-monomethylsterols and 4, 4′-dimethylsterols in olive oil as a result of variety, ripening, and storage temperature, 36 samples were subjected to gas chromatography with flame ionization detection (GC-FID) and with mass spectrometric detection (GC-MS), and results were processed by univariate and multivariate statistics. Relative amounts (percent) of β-amyrin, cycloartenol, and 24-methylenecycloartanol accounted for the most variation due to variety, while citrostadienol (percent) and 24-methylenecycloartanol (milligrams per 100 g) were strongly affected by ripening. Multivariate statistics differentiated olive oils regardless of storage conditions, which implied the possibility to use 4-monomethyl- and 4, 4′-dimethylsterols as indicators of variety and ripening degree for fresh and stored oils. Absolute changes in 4-monomethyl- and 4, 4′-dimethylsterols after storage were of a much smaller magnitude, meaning the investigated olive oils essentially retained health-beneficial features that derive from these compounds. Relative changes caused by storage were specific for each storage temperature and were useful in discriminating oils by linear discriminant analysis.