Sterol, triterpen dialcohol and fatty acid profile of less- and well-known Istrian monovarietal olive oil

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

Genetička, biokemijska, hranjiva i antimikrobna svojstva šipka (Punica granatum L.) uzgojenog u Istri

This study characterises the genetic variability of local pomegranate (Punica granatum L.) germplasm from the Slovenian and Croatian areas of Istria. The bioactive components and antioxidant and antimicrobial properties of ethanol and water extracts of different parts of pomegranate fruit were also determined, along with their preliminary nutritional characterisation. Twenty-six different genotypes identified with microsatellite analysis indicate the great diversity of pomegranate in Istria. The pomegranate fruit ethanol extracts represent rich sources of phenolic compounds (mean value of the mass fraction in exocarp and mesocarp expressed as gallic acid is 23 and 16 mg/g, respectively). The ethanol extracts of pomegranate exocarp and mesocarp showed the greatest antimicrobial activity against Candida albicans, Candida parapsilosis, Rhodotorula mucilaginosa, Exophiala dermatitidis and Staphylococcus aureus, and the same water extracts against S. aureus and Escherichia coli. To the best of our knowledge, this study represents the first report of the characterisation of pomegranate genetic resources from Istria at different levels, including the molecular, chemical, antimicrobial and nutritional properties.U ovom je radu opisana genetička raznolikost germplazme šipka (Punica granatum L.) s područja slovenskog i hrvatskog dijela Istre. U etanolnim i vodenim ekstraktima različitih dijelova ploda šipka pronađeni su bioaktivni spojevi, te su ispitana njihova antioksidacijska i antimikrobna svojstva i preliminarno određena hranjiva svojstva ekstrakata. Dvadeset i šest različitih genotipova utvrđenih analizom mikrosatelita upućuju na veliku raznolikost šipka u Istri. Etanolni ekstrakti ploda šipka predstavljaju bogat izvor fenolnih spojeva (srednja vrijednost masenog udjela, izraženog kao galna kiselina, bila je 23 mg/g u egzokarpu i 16 mg/L u mezokarpu). Etanolni ekstrakti egzokarpa i mezokarpa šipka imali su snažan antimikrobni učinak na sljedeće vrste: Candida albicans, Candida parapsilosis, Rhodotorula mucilaginosa, Exophiala dermatitidis i Staphylococcus aureus, dok su vodeni ekstrakti egzokarpa i mezokarpa uspješno suzbijali rast bakterija S. aureus i Escherichia coli. Prema našim spoznajama, ovo je prva karakterizacija genetičkih izvora šipka iz Istre, koja obuhvaća molekularna, kemijska, antimikrobna i hranjiva svojstva plodova

An Integrated Characterization of Jujube (Ziziphus jujuba Mill.) Grown in the North Adriatic Region

Žižula (Ziziphus jujuba Mill.) ima dobra hortikulturna svojstva, koja uključuju prilagodbu uvjetima suše, abiotskim i biotskim stresovima, te pozitivan utjecaj na zdravlje ljudi. U ovom je istraživanju opisana genska raznolikost germplazme žižule s istarskog poluotoka, te su određeni važni kemijski spojevi, antioksidacijski, antibakterijski i protugljivični učinak ekstrakata plodova žižule te njihova hranjiva svojstva. Rezultati analize gena pokazuju da većina uzoraka s istarskog poluotoka pripada dvjema nedavno introduciranim sortama, \u27Li\u27 i \u27Lang\u27, te najrasprostranjenijoj lokalnoj sorti Domaća žižula\u27. Lokalna sorta ima sitnije plodove od sorata \u27Li\u27 i \u27Lang\u27, s tanjim i mesnatijim mezokarpom. Kemijska je analiza pokazala da su plodovi lokalne sorte vrijedan izvor vlakana ((9,7±0,6) g/100 g), te da su bogati mineralima poput kalija ((829±51) g/ 100 g suhe tvari), kalcija ((1 77±1 1 ) g/ 1 00 g suhe tvari) i fosfora ((129±19) g/ 100 g suhe tvari). Vodeni su ekstrakti imali blagu antibakterijsku aktivnost, dok su etanolni ekstrakti imali veće masene udjele fenolnih spojeva (5,8-8,7 mg/g), izražene kao ekvivalent galne kiseline (GAE), od vodenih ekstrakata, no nisu imali antimikrobnu aktivnost. Osim fenolnih spojeva, i ostali spojevi u plodu žižule mogu imati veću biološku aktivnost. Na osnovi rezultata ovih analiza smatramo da lokalna istarska sorta žižule ima potencijal za uzgoj.Jujube (Ziziphus jujuba Mill.) has favourable horticultural properties including adaptation to arid conditions, abiotic and biotic stresses, as well as positive impact on human health. The present study describes the characterization of genetic diversity of the germplasm of jujube from the Istrian peninsula, the determination of important chemical compounds, antioxidative properties in relation to antibacterial and antifungal activities of jujube fruit extracts, and the determination of nutritional properties of jujube fruit. The results of the genetic analysis showed that most of the samples from the Istrian peninsula belong to two recently introduced varieties, \u27Li\u27 and \u27Lang\u27, and the most widespread local variety \u27Navadna žižola\u27. The local variety has smaller fruit than the ‘Li’ and ‘Lang’ varieties, with thick and fleshy mesocarp. Chemical analysis indicated that fruits of the local variety contained a valuable source of dietary fibre ((9.7±0.6) g/100 g) and were rich in minerals such as (in g/100 g dry mass): potassium (829±51), calcium (177±11) and phosphorus (129±19). Aqueous extracts showed slight antibacterial activity, while ethanol extracts had higher mass fractions of phenolic compounds (expressed as gallic acid equivalents (GAE), 5.8-8.7 mg/g) than the aqueous extracts, but did not show antimicrobial activity. Compounds other than phenolic compounds in jujube fruit may be more biologically active. Based on the results of these analyses, the local Istrian jujube variety is a promising candidate for cultivation potential

Selective Methods to Investigate Authenticity and Geographical Origin of Mediterranean Food Products

The Mediterranean diet is promoted as one of the healthiest and closely linked to socioecological practices, knowledge and traditions, promoting sustainable food production, and linking geographical origin with food quality and ecosystem services. Consumer adherence to this dietary pattern drives increased consumption of authentic “premium” foods, such as Iberian pig meat and dry-cured ham from Portugal and Spain, argan oil from Morocco, “Djebel” lamb from Tunisia and truffles from Italy and Slovenia, i.e., food products that respond to current ethical, environmental and socially sustainable demands. Geographical indication and appellation of origin can increase traditional food products competitiveness, but the high-value recognition of these products can also lead to economically motivated product adulteration. It is therefore imperative to protect the high added value of these unique food products by ensuring their quality, authenticity, provenance and sustainable production systems. In this review, we provide a critical evaluation of the analytical methods that are currently used for the determination of provenance and authenticity of these Mediterranean products as well as possible strategies for improving the throughput and affordability of the methods discussed.info:eu-repo/semantics/publishedVersio

The impact of selected technological procedures on chemical and sensory properties of Slovenian virgin olive oils

V raziskavi smo proučevali vpliv skladiščenja oljčnega olja na vsebnost biofenolov, alkilnih estrov in senzorične značilnosti svežega, eno in dve leti staranega oljčnega olja. Ugotovili smo značilno zastopane sekoiridoidne spojine DMO-AgL-dA, DML-Agl-dA, L-Agl-dA pri sorti \u27Istrska belica\u27, pri sorti \u27Leccino\u27 DMO-AgL-dA in pri sorti \u27Maurino\u27 DMO-Agl-dA, O-Agl-A. Razlike v vsebnosti skupnih biofenolov ter vsebnosti derivatov olevropeina in ligstrozida med olji sorte \u27Istrska belica\u27 in olji drugih sort so statistično značilne (ztotal= -5,049, ptotal <0,005zsec = -4,063, psec <0,005). Vsebnosti so se zelo razlikovale glede na sorto ter glede na letnik pridelave. S statističnim testom Wilcoxon–Mann–Whitney smo pokazali, da so razlike med intenzivnostjo grenkobe in pikantnosti v oljih sorte \u27Istrska belica\u27 v primerjavi z drugimi sortami, statistično značilne (zgrenkoba =-3,111, pgrenkoba= 0,002zpikantnost = -3,688, ppikantnost < 0,005). Analizirali smo 168 vzorcev olj in rezultati so potrdili korelacijo med vsebnostjo alkilnih estrov maščobnih kislin in senzoričnimi napakami. S pomočjo Spearman rank koeficienta smo dokazali šibke, a statistično značilne korelacije za opisnik pregreto in vsebnost alkilnih estrov maščobnih kislin (rs=0,3906) ter za senzorični opisnik žarko in vsebnost alkilnih estrov maščobnih kislin (rs=0,2995). V drugem sklopu raziskav smo proučevali vpliv filtracije na kakovost in obstojnost oljčnega olja. Iz rezultatov maščobnokislinske sestave, tokoferolov in biofenolov je razvidna le razlika med sortami, ni opaznih razlik med nefiltriranimi in filtriranimi olji kot tudi ne med svežimi in po šestih mesecih hranjenja na sobni temperaturi. Opazne razlike pa smo ugotovili v senzorični oceni in večji vsebnosti tirozola in hidroksitirozola v nefiltriranih oljih.V tretjem sklopu smo izvedli prvi namakalni poskus za oljke, da bi proučili sušni stres pri sorti \u27Istrska belica\u27, kjer smo poleg dinamike porabe vode, ugotavljali tudi velikost pridelka (kg/ha) in vsebnost olja v plodovih (%) ter maščobnokislinsko sestavo, vsebnost biofenolov ter senzorične značilnosti. Z analizami v letu 2014 smo potrdili, da lahko z namakanjem od 30 % potencialne evapotranspiracije (ETp) do 40 % ETp zagotovimo dovolj visoko vsebnost biofenolov in hkrati vplivamo na ugodno razmerje med biofenoli olevropeinskega in ligstrozidnega izvora.The study examined the effects of olive oil storage on the content of biophenols, alkyl esters and sensory characteristics of fresh and one and two years of stored olive oils. Monitoring of the biophenolic composition of fresh oil revealed that some secoiridoid compounds are more abundant in certain varieties, in particular DMO-AgL-dA, DML-Agl-dA, L-Agl-dA in the cv. ‘Istrska belica’, DMO-AgL-dA in the cv. \u27Leccino\u27 and DMO-Agl-dA and O-Agl-A in the cv. \u27Maurino \u27.The statistical test showed that differences in the content of total biophenols and the content of oleuropine and ligstroside derivatives between cv. ‘Istrska belica’ and other varieties were statistically significant (ztotal = -5.049, ptotal <0.005zsec = -4.063, psc <0.005). The values differred according to the variety and the crop year. With the Wilcoxon-Mann-Whitney statistical test, the differences between the degree of bitterness and pungency in olive oils in the ‘Istrska belica’ variety were statistically significant (zbitterness = -3,111, pbitterness = 0,002, zpungency = -3,688, p <0.005). 168 samples of oils were analyzed, and the results confirmed the correlation between the content of fatty acid alkyl esters and the detected sensory defects. With the statistical test Spearman rank corr., we have shown that correlations are weak, but statistically significant for the sensory descriptor of heated and alkyl esters of fatty acids (rs = 0.3906) and for the sensory descriptions of the rancidity and alkyl esters of fatty acids (rs = 0.2995). In the second series of studies the influence of filtration on the quality and stability of olive oil was studied. The stability of olive oil depends primarily on the content of antioxidants (biophenols and tocopherols) and fatty acid composition, while sensory score is very important for monitoring the quality. From the results of the monitoring of the fatty acid composition and the content of tocopherols and biophenols, only the difference between cultivars is evident, there are no noticeable differences between unfiltered and filtered oils, as well as between fresh and 6 months old oils stored at room temperature. Significant differences were found in the sensory scores and in the levels of tyrosol and hydroxythyrosol, both were higher in unfiltered oils. In the third series of studies we carried out the first irrigation experiment for olives to study the drought stress in the cv. ‘Istrska belica’. In addition to the dynamics of water consumption, the crop quantity (kg/ha), the content of oil in the olive drupes (wt. %) and the fatty acid composition, the content and composition of biophenols in oil samples were determined

The effect of olive fruit fly Bactrocera oleae (Rossi) infestation on certain chemical parameters of produced olive oils

Olives affected by active and damaging infestation (olive fruit fly Bactrocera oleae (Rossi)) were assayed for their chemical composition. Biophenols were determined by HPLC, sterols, triterpenic dialcohols, and fatty acids by gas chromatography analysis. The acquired data were statistically analyzed. Oils produced from %Istrska belica% fruit affected by active infestation compared to the oils made from fruit affected by damaging infestation showed higher amounts of total oleuropein biofenols (377.3 versus (vs.) 106.6 mg/kg), total biophenols (755 vs. 377 mg/kg), lignans (85.3 vs. 32.9mg/kg), the dialdehydic formof decarboxymethyl oleuropein aglycone (DMO-AgldA) (148.3 vs. 49.0 mg/kg), its oxidized form (DMO-Agl-dA)ox (35.2 vs. 8.5 mg/kg), the dialdehydic form of oleuropein aglycone (O-Agl-dA) (61.1 vs. 8.0 mg/kg), the dialdehydic form of ligstroside aglycone (L-Agl-dA) (63.5 vs. 28.0 mg/kg), the aldehydic form of oleuropein aglycone (O-Agl-A) (40.6 vs. 8.4 mg/kg), and lower amounts of tyrosol (Tyr) (6.0 vs. 13. 9 mg/kg) and the aldehydic form of ligstroside aglycone (L-Agl-A) (13.8 vs. 40.3 mg/kg). Higher values of stigmasterol (2.99%) and lower values of campesterol (2.25%) were determined in oils affected by damaging infestationan increase in triterpenic dialcohols was also observed (3.04% for damaging and 1.62% for active infestation). Oils affected by damaging infestation, compared to active infestation, showed lower amounts of oleic acid (73.89 vs. 75.15%) and higher amounts of myristic (0.013 vs. 0.011%), linoleic (7.27 vs. 6.48%), and linolenic (0.74 vs. 0.61%) acids