Pressurized Liquid Extraction: A Powerful Tool to Implement Extraction and Purification of Food Contaminants

Pressurized liquid extraction (PLE) is considered an advanced extraction technique developed in the mid-1990s with the aim of saving time and reducing solvent with respect to traditional extraction processes. It is commonly used with solid and semi-solid samples and employs solvent extraction at elevated temperatures and pressures, always below the respective critical points, to maintain the solvent in a liquid state throughout the extraction procedure. The use of these particular pressure and temperature conditions changes the physicochemical properties of the extraction solvent, allowing easier and deeper penetration into the matrix to be extracted. Furthermore, the possibility to combine the extraction and clean-up steps by including a layer of an adsorbent retaining interfering compounds directly in the PLE extraction cells makes this technique extremely versatile and selective. After providing a background on the PLE technique and parameters to be optimized, the present review focuses on recent applications (published in the past 10 years) in the field of food contaminants. In particular, applications related to the extraction of environmental and processing contaminants, pesticides, residues of veterinary drugs, mycotoxins, parabens, ethyl carbamate, and fatty acid esters of 3-monochloro-1,2-propanediol and 2-monochloro-1,3-propanediol from different food matrices were considered

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

Steiner inellipse and the three-city noxious location problem

V diplomski nalogi bomo predstavili Steinerjevo včrtano elipso. Na začetku si ogledamo povezavo med ničlami kubičnega polinoma in ničlami njegovega odvoda. Nato navedemo Steinerjev izrek in ga dokažemo z uporabo afinih transformacij. V nadaljevanju raziščemo povezavo med ploščino trikotnika in ploščino Steinerjeve včrtane elipse. V zadnjem poglavju se posvetimo aplikaciji rezultatov o Steinerjevi včrtani elipsi v lokacijski teoriji.The main topic of this thesis is the Steiner inellipse and its properties. We establish the connection between the roots of a third-degree polynomial and the roots of its derivative. Then we state Steiner\u27s theorem and prove it using affine transformations. Further we research the area of a triangle and its Steiner inellipse. In addition, we introduce the application of the Steiner inellipse in the noxious location problem