50 research outputs found
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.
Ī²-sitosterol, Ī-5-avenasterol and campesterol were the most abundant sterols in
all samples. Campesterol, Ī²-sitosterol and Ī-5-avenasterol most significantly
differentiated investigated oils. Bova oil had the highest amount of total sterols
(2964 Ā± 458 mg/kg). Istarska bjelica oil had a peculiar sterol composition with
exceptionally low Ī²-sitosterol (67%), high Ī-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
GenetiÄka, biokemijska, hranjiva i antimikrobna svojstva Å”ipka (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 genetiÄka raznolikost germplazme Å”ipka (Punica granatum L.) s podruÄja slovenskog i hrvatskog dijela Istre. U etanolnim i vodenim ekstraktima razliÄitih dijelova ploda Å”ipka pronaÄeni su bioaktivni spojevi, te su ispitana njihova antioksidacijska i antimikrobna svojstva i preliminarno odreÄena hranjiva svojstva ekstrakata. Dvadeset i Å”est razliÄitih genotipova utvrÄenih analizom mikrosatelita upuÄuju na veliku raznolikost Å”ipka u Istri. Etanolni ekstrakti ploda Å”ipka 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 Å”ipka imali su snažan antimikrobni uÄinak na sljedeÄe vrste: Candida albicans, Candida parapsilosis, Rhodotorula mucilaginosa, Exophiala dermatitidis i Staphylococcus aureus, dok su vodeni ekstrakti egzokarpa i mezokarpa uspjeÅ”no suzbijali rast bakterija S. aureus i Escherichia coli. Prema naÅ”im spoznajama, ovo je prva karakterizacija genetiÄkih izvora Å”ipka iz Istre, koja obuhvaÄa 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 ukljuÄuju prilagodbu uvjetima suÅ”e, abiotskim i biotskim stresovima, te pozitivan utjecaj na zdravlje ljudi. U ovom je istraživanju opisana genska raznolikost germplazme žižule s istarskog poluotoka, te su odreÄeni važni kemijski spojevi, antioksidacijski, antibakterijski i protugljiviÄni uÄinak ekstrakata plodova žižule te njihova hranjiva svojstva. Rezultati analize gena pokazuju da veÄina uzoraka s istarskog poluotoka pripada dvjema nedavno introduciranim sortama, \u27Li\u27 i \u27Lang\u27, te najrasprostranjenijoj lokalnoj sorti DomaÄa 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 ((9,7Ā±0,6) g/100 g), te da su bogati mineralima poput kalija ((829Ā±51) g/ 100 g suhe tvari), kalcija ((1 77Ā±1 1 ) g/ 1 00 g suhe tvari) i fosfora ((129Ā±19) g/ 100 g suhe tvari). Vodeni su ekstrakti imali blagu antibakterijsku aktivnost, dok su etanolni ekstrakti imali veÄe 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 veÄu bioloÅ”ku 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 āLiā and āLangā varieties, with thick and fleshy mesocarp. Chemical analysis indicated that fruits of the local variety contained a valuable source of dietary fibre ((9.7Ā±0.6) g/100 g) and were rich in minerals such as (in g/100 g dry mass): potassium (829Ā±51), calcium (177Ā±11) and phosphorus (129Ā±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 āpremiumā foods, such as Iberian pig meat and dry-cured ham from Portugal and Spain, argan oil from Morocco, āDjebelā 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 prouÄevali vpliv skladiÅ”Äenja oljÄnega olja na vsebnost biofenolov, alkilnih estrov in senzoriÄne znaÄilnosti svežega, eno in dve leti staranega oljÄnega olja. Ugotovili smo znaÄilno 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 statistiÄno znaÄilne (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 statistiÄnim testom WilcoxonāMannāWhitney smo pokazali, da so razlike med intenzivnostjo grenkobe in pikantnosti v oljih sorte \u27Istrska belica\u27 v primerjavi z drugimi sortami, statistiÄno znaÄilne (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 maÅ”Äobnih kislin in senzoriÄnimi napakami. S pomoÄjo Spearman rank koeficienta smo dokazali Å”ibke, a statistiÄno znaÄilne korelacije za opisnik pregreto in vsebnost alkilnih estrov maÅ”Äobnih kislin (rs=0,3906) ter za senzoriÄni opisnik žarko in vsebnost alkilnih estrov maÅ”Äobnih kislin (rs=0,2995). V drugem sklopu raziskav smo prouÄevali vpliv filtracije na kakovost in obstojnost oljÄnega olja. Iz rezultatov maÅ”Äobnokislinske 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 Å”estih mesecih hranjenja na sobni temperaturi. Opazne razlike pa smo ugotovili v senzoriÄni oceni in veÄji vsebnosti tirozola in hidroksitirozola v nefiltriranih oljih.V tretjem sklopu smo izvedli prvi namakalni poskus za oljke, da bi prouÄili suÅ”ni stres pri sorti \u27Istrska belica\u27, kjer smo poleg dinamike porabe vode, ugotavljali tudi velikost pridelka (kg/ha) in vsebnost olja v plodovih (%) ter maÅ”Äobnokislinsko sestavo, vsebnost biofenolov ter senzoriÄne znaÄilnosti. 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. āIstrska belicaā, 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. āIstrska belicaā 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 āIstrska belicaā 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. āIstrska belicaā. 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
Bioactive compounds in the oils of the autochthonous slovenian olive varieties āBugaā, āÄrnicaā and āDrobnicaā
The adaptation of autochthonous olive varieties to local soil and climatic conditions can lead to a unique chemical composition and characteristics of olive oils that may differ from the generally accepted quality standards set out in the International Olive Oil Council strategy documents and EU regulations. Therefore, the fatty acid composition, biophenol, tocopherol, sterol and triterpenic dialcohol content and composition of the autochthonous Slovenian olive varieties āBugaā, āCrnicaā Ė and āDrobnicaā were studied for a three-year period with the aim of valorising the characteristics of the three olive varieties. Standardised and accredited analytical methods in accordance with SIST EN ISO/IEC 17025:2017 were applied. The results of the investigation showed that the highest average amount of oleic acid (75.75%) was found in the oils of the āCrnicaā variety, followed by the āDrobnicaā Ė (72.06%) and the āBugaā (68.73%). All three varieties are a good source of total biophenols (āBugaā 616 mg/kg, āDrobnicaā 569 mg/kg and āCrnicaā 427 mg/kg) and Ė Ī±-tocopherol (āBugaā 378 mg/kg, āDrobnicaā 279 mg/kg, and āCrnicaā 243 mg/kg). āBugaā and āDrobnicaā are characterised by high Ė amounts of total sterols, 2468 mg/kg and 2391 mg/kg, respectively, while āCrnicaā oils, in comparison, Ė showed a lower average value of total sterols (1351 mg/kg). Due to their exceptional chemical composition, āBugaā, āCrnicaā and āDrobnicaā show great potential for the further cultivation and Ė valorisation of traditional olive oil production in the region, thus contributing to the preservation of biodiversity and local traditions. The quality parameters of olive oil from the autochthonous Slovenian olive varieties āBugaā, āCrnicaā and āDrobnicaā also fulfil the limits for extra virgin olive oil Ė according to the Commission Delegated Regulation (EU) 2022/2104, despite local climatic influences. However, accelerated growth due to climatic changes affecting early harvest can lead to them falling outside these limits, which was observed in particular for the āBugaā variety in terms of the linoleic acid content. This study emphasises the importance of timing the harvest to achieve optimum maturity and meet EU quality standards, taking into account the genetic makeup of the varieties and their response to the current climatic conditions