Graševina bijela najzastupljenija je i gospodarski najvažnija sorta u Republici Hrvatskoj. Uzgaja se u vinogradarskim regijama Zapadna i Istočna kontinentalna Hrvatska. Njena prilagodljivost ...klimatskim uvjetima jedna je od brojnih karakteristika koje ovu sortu čine popularnom među vinogradarima. Uočena je unutarsortna varijabilnost među populacijom Graševine bijele zbog čega je 2004. godine pokrenut projekt klonske selekcije na području vinogorja Kutjevo. U razdoblju od 2004. do 2015. godine, odabrano je dvanaest klonskih kandidata koji su se istaknuli od ostatka populacije po pozitivnim osobinama. Ovih dvanaest klonskih kandidata posađeno na Vinogradarsko-vinarsko pokušalište Jazbina s ciljem daljnjeg proučavanja njihovih karakteristika te nastavka postupka individualne klonske selekcije. Nakon ulaska nasada u puni rod, provedeno je proučavanje najbitnijih gospodarskih karakteristika. Utvrđene su značajne razlike između klonova za sljedeća svojstva: prirod, broj grozdova po trsu, osnovni pokazatelji kakvoće mošta.
Polifenolni sastav grožđa i vina predmet je brojnih istraživanja, ponajviše zbog utjecaja pojedinačnih polifenola na senzorna svojstva vina te njihovog blagotvornog učinka na ljudsko zdravlje. Zbog ...klimatskih promjena koje postaju učestalije sve više se susrećemo s problemom fenolne zrelosti grožđa. Stoga je cilj istraživanje bio utvrditi utjecaj inaktivnih kvasaca na dozrijevanje grožđa Plavine te postizanje optimalne fenolne zrelosti. Na početku fenofaze šare dio grožđa tretiran je inaktivnim kvascima (Lalvigne mature), a kao kontrolna varijanta poslužilo je grožđe sorte Plavina na kojoj nije proveden tretman. U uzorcima grožđa provedena je osnovna fizikalno-kemijska analiza te analiza aromatskog i polifenolonog sastava. Značajna razlika uočena je u koncentracijama petunidin-3-O-glukozida i peonidin-3-O-glukozida kao i kemferol-3-O-rutinozida te procijanidina B1 kod tretiranog grožđa dok je ukupna kiselost bila izraženija u kontrolnom tretmanu. U aromatskom profilu tretirano grožđe izdvojilo se većim sadržajem monoterpena dok su seskviterpeni bili zastupljeniji u kontrolnom tretmanu. S obzirom na proizvodna svojstva sorte Plavina kao što su tanka kožica, osjetljivost na bolesti, zbijen grozd i velike bobice s manjom mogućnosti nakupljanja suhe tvari, od kojih se najčešće proizvedu laganija, slabija obojena vina, manje bogata polifenolima, primijenjena tehnologija ukazuje na mogućnost unaprjeđenja kvalitativnih svojstava sorte Plavina a time i vina. Plavina, grožđe, polifenoli, inaktivni kvasci
Due to the short period of the grape fresh samples availability and their very complex analysis, appropriate grape samples storage is mandatory. In this study, samples were analyzed immediately after ...harvest and after storage at −20 °C. Frozen samples were thawed as follows: at the room temperature, in the microwave oven, in the refrigerator, and the skin was pulled off from the frozen grape berries. The freezing had a positive effect on the contents of anthocyanins and flavonol glycosides. These compounds are contained in cell vacuoles thus membrane degradation, throughout the freezing process, could enhance their extractability. The freezing had a negative effect on the content of the other polyphenols which can be bound to the cell wall. Among examined thawing methods, the most appropriate method was the peeling grape berry skin from the frozen berries samples with the receptacle. Suitable alternative to the aforementioned method could be the microwave thawing.
Practical application
One of the most important groups of compounds contained in grape berries are polyphenolic compounds. These compounds significantly affect the quality of grapes and wine. They also have a positive impact on human health. Most of the grapes are being processed into wine, but it also has many other uses. Besides the table grapes, raisins, juices, jams, and wine distillates, currently, various cosmetic and pharmaceutical preparations made from grapes whose functioning is based on the effects of polyphenols are encounter on the market. Given the short period of availability of fresh grape samples and complex procedure of their analysis and processing, samples must be stored in an appropriate manner. This study reported the effect of freezing and applied thawing method on retentions of polyphenolics in grapes. The information obtained by this study is essential for the development of specific applications of the grape berries skins.
Grape marc seeds contain large amounts of different polyphenolic compounds so they can be used for the recovery of these classes of compounds. A new green extraction method for the recovery of ...phenols from the grape seeds was developed. To provide a high quality extract sourced from natural product by using enzymes as alternative solvents and spending less energy, it is impeccable to call this method “green”. Furthermore, this method was optimized by finding out which conditions provide the best possible results and achieving the maximum recovery of polyphenols from grape seeds. The optimization of the enzyme-assisted extraction of phenols was conducted using the commercially available oenological enzyme preparations with respect to the enzyme dosage, temperature, extraction time, pH value and enzyme preparation by applying the response surface methodology. Optimal conditions were determined using the enzyme preparation Lallzyme EX-V, at the extraction temperature of 48 °C, extraction time of 2 h and 43 min, pH 3.5 and enzyme dosage of 20.00 mg g
−1
. The new optimized extraction method is less expensive, simple, fast, precise and selective for the recovery of simple phenols (monomeric and dimeric form) and since it is based on the environmentally friendly extraction solvent it may provide a valuable alternative to the conventional extraction methods. The obtained extracts can be used for the application in pharmaceutical, food and cosmetic industry.
Defolijacija je jedan od zahvata zelene rezidbe tijekom kojeg se vrši prorjeđivanje ili potpuno uklanjanje lisne mase u zoni grožđa. Ako se djelomična defolijacija provodi u fenofazi cvatnje vinove ...loze smatra se ranom dok se defolijacija u fenofazi šare smatra kasnom defolijacijom. Cilj ovog istraživanja je utvrditi utjecaj djelomične defolijacije provedene u različitim fenofazama (jedna varijanta predstavlja bazalnu defolijaciju u fenofazi zametanja boba, druga bazalnu početkom šare, a treća defolijaciju iznad zone grozda, također početkom šare) na kemijski sastav grožđa sorte Graševina u podregiji Slavonija.
Defoliation is one of the green pruning interventions in which thinning or complete removal of leaves in the grape zone is performed. If partial defoliation is carried out in the grapevine during the flowering phase, it is considered an early defoliation, while defoliation in the pattern phase is considered to be a late defoliation. The aim of this study was to investigate the influence of partial defoliation performed in three different variants (one variant represents basal defoliation in grape berries flowering phenophase, the second variant basal defoliation at the beginning of the verison, and the third variant represents defoliation above the cluster zone, also at the beginning of the verison) on the chemical composition of Graševina variety in Slavonia.
Fenolni spojevi predstavljaju sekundarne biljne metabolite koji imaju vrlo važnu fiziološku i morfološku ulogu u rastu i reprodukciji biljke pružajući joj i zaštitu protiv patogena i predatora. Cilj ...ovoga istraživanja je dobiti pregled promjena u sastavu i sadržaju fenolnih spojeva odnosno flavonola, flavanola, hidroksicimetnih i hidroksibenzojevih kiselina prisutnih u listovima četiri različite crne sorte vinove loze. Ekstrakti su analizirani tekućinskom kromatografijom visoke djelotvornosti. Dobivenim rezultatima utvrđena je značajna varijabilnost u masenim udjelima fenolnih spojeva između sorata po pojedinim terminima uzorkovanja, kao i značajna varijabilnost u sadržaju fenolnih spojeva unutar iste sorte tijekom različitih termina uzorkovanja.
Phenolic compounds represent secondary plant metabolites which play an important physiological and morphological role in plant growth and reproduction. They also provide a protection against pathogens and predators. The aim of this study is to obtain an overview of changes in the composition and phenolic compounds content, more precisely flavonols, flavanols, hydroxycimetic and hydroxybenzoic acids present in the leaves of four different grapevine varieties. The extracts were analyzed by high performance liquid chromatography. Based on the obtained results, significant variability in mass shares of phenolic compounds between varieties was determined by individual sampling terms, as well as significant variability in the content of phenolic compounds within the same variety during different sampling terms.
Otporne sorte vinove loze nezasluženo se vežu za negativne konotacije prvih križanaca koji su nastali na samom početku korištenja međuvrsne hibridizacije, odnosno u drugoj polovini 19. stoljeća. ...Korištenjem kvalitetnog materijala, pomno osmišljenih pokusa i znanstvenih dostignuća postupak oplemenjivanja danas je potpuno promijenio paradigmu od empirijskog načina rada do striktno ciljanog dizajna križanja čime u posljednjih dvadesetak godina nastaju sorte izvrsnih gospodarskih karakteristika uključujući visoku razinu otpornosti na plamenjaču i pepelnicu. Te sorte prikladne su za uzgoj vinove loze uz bitno manju uporabu fungicida, kao i za ekološki uzgoj. Zbog povoljna utjecaja na okoliš i zdravlje ljudi takvi načini proizvodnje u skladu su s ciljevima europske strategije „Od polja do stola“. Povijesni pregled oplemenjivanja, od dolaska američkih bolesti i štetnika na europski kontinent do najnovije generacije otpornih sorata, kao i procjena perspektive za njihovo šire prihvaćanje u proizvodnji, nalazi se u nastavku.
•Varieties with different GEN-GEO background have different polyphenolic profiles.•The most abundant classes of phenols are anthocyanins, flavan-3-ols, and flavonols.•Polyphenolic profiles ...discriminated GEN-GEO groups.
Relevant aspect of wine geographic origin is related to grapevine varieties used for wine production in specific wine country or region. The grapevine germplasm is highly variable and classified into geographic groups. These classifications were recently confirmed using genetic studies, and further classified varieties into geographic-genetic (GEN-GEO) groups. Polyphenolic compounds are important secondary metabolites in grapes and have an important impact on wine quality and sensory properties. The aim of this research was to investigate the polyphenolic profiles of 50 grape varieties from different GEN-GEO groups. The groups were C2 (varieties from Italy and France), C7 (varieties from Croatia), C8 (varieties from Spain and Portugal). Polyphenolic compounds analysed belonged to the classes of anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes. The most abundant classes of polyphenols were anthocyanins, followed by flavan-3-ols and flavonols. Using discriminant analysis, the genetic-geographic groups were clearly separated based on their polyphenolic profiles, with all classes of compounds contributing to discrimination.
Commission Regulation (EU) 2017/1485 of 2 August 2017 establishing a guideline on electricity transmission system operation defines a prequalification process as a process to verify the compliance of ...a reserve providing unit or a reserve providing group with the requirements set by the transmission system operator. Croatian Transmission System Operator Plc. (HOPS) carries out a prequalification process in order for (potential) ancillary service providers to prove their capability of providing ancillary services, which means that the prequalification process is a prerequisite for the provision of ancillary services. As part of the European Network of Transmission System Operators for Electricity, HOPS participates in the European implementation projects PICASSO and MARI, which aim is to establish a single European platform for aFRR and mFRR balancing services. Within the PICASSO and MARI projects, the technical characteristics of the products traded on unique European platforms were defined. This paper analyzes the difference between the requirements from the existing prequalification process rules and the technical requirements for products within the PICASSO and MARI projects, explores practice in Slovenia and Germany and suggests the required adoptions of aFRR and mFRR prequalification process in Croatia.
Cilj ovog rada bio je utvrditi učinak različitih postupaka sušenja: liofilizacije, sušenja u sobi i sušenja u pećnici na fenolni sastav grožđa sorata 'Regent' i 'Cabernet Sauvignon'. Nakon sušenja ...uzorci su usitnjeni, podvrgnuti ultrazvukom potpomognutoj ekstrakciji te potom analizirani primjenom tekućinske kromatografije visoke djelotvornosti. Ovo je istraživanje jasno pokazalo da uporaba različitih metoda sušenja značajno utječe na sadržaj polifenola u ekstraktima kožice grožđa. Najveći sadržaj antocijan-diglukozida sačuvan je liofilizacijom, 15706.86 mg/kg u slučaju 'Regenta', dok je sadržaj antocijan-monoglukozida najbolje očuvan sušenjem pri sobnoj temperaturi, 216778.68 i 9220.30 mg/kg u slučaju 'Regenta' odnosno 'Cabernet Sauvignona'. Najveći sadržaj flavonol-glikozida (2583.04 i 1429.64 mg/kg u slučaju 'Regenta' odnosno 'Cabernet Sauvignona'), hidroksicimetnih kiselina (1303.31 i 544.88 mg/kg u slučaju 'Regenta' odnosno 'Cabernet Sauvignona') i stilbena (2321.52 i 79.36 mg/kg u slučaju 'Regenta' odnosno 'Cabernet Sauvignona') zabilježen je u uzorcima sušenim u pećnici. Primjenom liofilizacije očuvan je najoptimalniji sadržaj flavan-3-ola. Sadržaj polifenolskih spojeva u uzorcima sušenim u pećnici, nakon razdoblja od 6 mjeseci skladištenja, bio je gotovo identičan sadržaju u uzorcima analiziranim neposredno nakon sušenja. Najveća razgradnja zabilježena je u uzorcima sušenim u
sobi, dok je u liofiliziranim uzorcima bila umjerena. Rezultati ovog eksperimenta pokazuju da je uzorke potrebno sušiti na različite načine kako bi se dobio najveći sadržaj određenih skupina fenolnih spojeva. Primjena metode sušenja određena je konačnim ciljem osušenog proizvoda s obzirom na sadržaj i sastav različitih polifenolskih spojeva; stoga bi dobiveni rezultati mogli imati primjenu u znanstvenim istraživanjima, ali i u komercijalne svrhe.
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