Mlada rdeča vina izpostavljena kisiku lahko pod določenimi pogoji pridobijo na kakovosti. Proces mikrooksidacije je osnovna metoda, s katero lahko vplivamo na fenolno strukturo vin, ki skuša ...prilagajati količino dodanega kisika vinu z namenom povečati stabilnost barve, zmehčanja trpkih taninov in zmanjšanja neprijetnih arom. Proučevali smo vpliv mikrooksidacije na spremembo barve in vsebnosti fenolnih spojin vina modri pinot. Analize so vključevale določanje skupnih fenolov, taninov, netaninov, flavonoidov in neflavonoidov, antocianov, intenzitete barve, tona barve, deleža rdeče barve pri posameznih valovnih dolžinah (420, 520 in 620 nm), oceno koncentracije pigmenta odpornega na SO2 ter primerjavo končnega in kontrolnega vzorca v kemijskih parametrih (pH, prosti in vezani SO2, alkohol, skupni suhi ekstrakt, skupne, titrabilne in hlapne kisline). Rezultati so pokazali, da je mikrooksidacija povzročila spremembo barvnega značaja, izboljšanje intenzitete barve procesiranega vzorca v primerjavi s kontrolnim, vzpodbudila tvorbo polimernih barvil in kopigmentiranih kompleksov, s tem pa mehčanje taninov (polimerizacija fenolnih spojin) in stabilizacijo barve, ki je odporna na vezavo z SO2.
Cilj ovog istraživanja bio je utvrditi utjecaj glutationa na kemijski sastav i senzorna svojstva vina 'Pošip' pri čemu je njegova primjena provedena prije te tijekom primarne prerade grožđa. ...Uspoređivani su rezultati fizikalno kemijskog sastava vina , sadržaj otopljenog kisika i ukupnih fenola te parametara boje između kontrolnog uzorka te tretmana uz dodatak glutationa na svježe grožđe (GG) i mošt (GM). Tretman glutationom imao je najveći utjecaj na topljivost kisika te nijansu i intenzitet boje u tretmanu GM, dok je najviša koncentracija ukupnih fenola bila u tretmanu GG. Senzornim ocjenjivanjem vina ´Pošip´ različitih tretmana nisu utvrđene značajne razlike u mirisu, okusu i općem dojmu.
The aim of this study was to determine the impact of glutathione addition before and during primary processing on the basic physicochemical parameters and sensory properties of Pošip wine. The following measurement results were compared between the control sample, the glutathione treatment of fresh grapes (GG) and the addition of glutathione to must (GM): dissolved oxygen in wine, total phenols, color and sensory evaluation of wine. The results have shown the glutathione to have the greatest impact on oxygen dissolution and color hue and intensity in the GM sample, while the most total phenols were obtained in GG treatment. Sensory evaluation did not reveal significant differences in the aromatic profile, taste, and general impression between Pošip wines.
Iako klasična proizvodnja bijelih vina podrazumijeva fermentaciju mošta, suvremeni trendovi podrazumijevaju proizvodnju bijelih vina uz maceraciju, odnosno fermentaciju masulja. Cilj ovog rada bio je ...utvrditi utjecaj duge maceracije grožđa na kakvoću vina 'Graševina'. Istraživanje je provedeno tijekom 2021. godine u vinogradima i vinskom podrumu Veleučilišta u Požegi u vinogorju Kutjevo. Nakon berbe, kontrolni uzorak vina proizveden je klasičnim postupkom proizvodnje bijelih vina, te su provedena dva tretmana duge maceracije u periodu od 3 mjeseca - jedan uz sulfitiranje tijekom primarne prerade a drugi bez sulfita. U vinima su analizirani osnovni parametri kakvoće, koncentracija jabučne i mliječne kiseline, optička gustoća pri 280 nm, ukupni fenoli i antioksidativna aktivnost DPPH metodom. Statistički značajna razlika zabilježena je kod ukupnih fenola, kao i antioksidativnoj aktivnosti, s najvećim vrijednostima u maceriranom uzorku uz primjenu SO2. Organoleptičko ocjenjivanje uzoraka proveli su certificirani ocjenjivači, metodom 100 bodova. Najveću prosječnu ocjenu od 87 bodova dobilo je vino proizvedeno dugom mareracijom grožđa uz redovito sulfitiranje. Kontrolni tretman slabije je ocijenjen, sa 72 boda. Vino proizvedeno dugom maceracijom bez korištenja sulfita ocjenjeno je sa 66 boda uz napomenu pojedinih ocjenjivača o izraženoj oksidaciji.
Although classical production of white wines involves the fermentation of must, recently there has been a trend in the production of white wines with maceration processor fermentation of pomace. The aim of this paper is to determine the influence of long maceration of pomace on the quality of Graševina wine. The research was conducted in 2021 in the vineyards and wine cellar of the Polytechnic of Požega in the Kutjevo wine-growing hill. After harvesting, a control treatment was white wine produced by the classic production process, and a long maceration process was carried out on other two treatments over a period of 3 months, in two treatments - one with sulfites during primary processing and the other without sulfiting. The following basic parameters were determined in wines: alcoholic strength, reducing sugars, total acidity, malic, lactic acid, volatile acidity, pH, absorbance at 280 nm, total phenols and antioxidant activity by DPPH method. There was a statistically significant difference in the total phenols content, as well as antioxidant activity, with the highest values in the macerated sample containing SO2. Organoleptic evaluation of samples was performed by trained evaluators, using the 100-point method. The highest average score of 87 points was given to wine produced by long maceration with regular sulfiting during primary processing. Control treatment was rated lower by 72 points. Wine produced by long maceration without the use of sulfiting in the primary processing was evaluated with an average score of 66 points with a few remarks about the oxidation pronounced in the wine aroma.
Prirodno pjenušavo ružičasto vino od autohtonog kultivara vinove loze Teran (Vitis vinifera L.) proizvedeno je metodom vrenja u boci uz primjenu inkapsuliranog kvasca ProElif® (Saccharomyces ...cerevisiae) i komercijalnog suhog kvasca Fermol Blanc (Saccharomyces bayanus). Tijekom istraživanja uspoređivana je aktivnost korištenih kvasaca s obzirom na brzinu razgradnje šećera tijekom fermentacije u boci te njihov
utjecaj na osnovna fizikalno kemijska svojstva i fenolni profil gotovog pjenušavog vina te parametre pjene i iskrenja. Brža razgradnja šećera, kao i veći udio pojedinačnih i ukupnih fenolnih spojeva utvrđen je u pjenušavim vinima proizvedenim primjenom inkapsuliranog kvasca ProElif®. S druge strane, vina proizvedena kvascem Fermol Blanc odlikovala su se višim suhim ekstraktom te većom kvalitetom pjene i iskrenja. Uočene senzorske razlike u vinima nisu imale negativnih implikacija pri definiranju njihove sveobuhvatne kakvoće.
The influence of encapsulated yeast ProElif® (Saccharomyces cerevisiae) in comparison with the yeast Fermol Blanc (Saccharomyces bayanus) in the production of naturally sparkling rosé wine by bottle fermentation produced from the indigenous grape cultivar Teran (Vitis vinifera L.) was investigated. During the research, the following were monitored: the length of sugar decomposition during fermentation in the bottle, and in the finalized sparkling wines, physicochemical parameters, foam and sparkling parameters and phenolic profile. Faster breakdown of sugars, as well as a higher proportion of individual and total phenolic compounds have been recorded in wines with ProElif® yeast. On the other hand, wines produced with Fermol Blanc yeast were characterized by a higher dry extract and higher quality of foam and sparkling. Sensory differences were observed in wines without negative implications for their final quality.
'Dobričić' je stara autohtona sorta vinove loze podrijetlom s otoka Šolte, a njezin plod je nadaleko prepoznatljiv je po intenzivnoj tamnocrvenoj boji pokožice. Nekada je ova sorta vinove loze ...sačinjavala glavninu trsova otočkih vinograda. Danas je u revitalizaciji kao otočni brend. DNK analizom su utvrđene njezine srodne veze s mnogim dalmatinskim sortama. Vino proizvedeno od sorte 'Dobričić' je bogato tvarima boje, ukupnim i pojedinačnim fenolima, te pokazuje značajnu antioksidacijsku aktivnost.
The phenolic profile of the wine of the grape variety ´Dobričić´ in relation to the wines of related varieties Dobričić is an old autochthonous grape variety originating from the island of Šolta. It is recognizable by its intense dark red color. It used to make up the majority of the island's vineyards. Today it is in revitalization as an island brand. DNA analysis has established its related links with many Dalmatian varieties. Wine is rich in color substances, total and individual phenols, and shows significant antioxidant activity.
Šljiva (Prunus domestica L.) je koštičava voćna vrsta vrlo cijenjena zbog poželjnih senzornih i nutritivnih svojstava plodova. Plodovi se konzumiraju svježi ili se prerađuju. Zbog relativno visokog ...sadržaja šećera i niže ukupne kiselosti plodovi sorte 'Stanley' predstavljaju dobar izbor za proizvodnju voćnih vina. Voćna vina proizvode se aktivnošću kvasaca u procesu alkoholne fermentacije. Obzirom da metabolizmom kvasaca nastaje čitav niz metabolita, izborom odgovarajuće vrste ili soja utječe se na tip vina koje se proizvodi. Cilj ovog rada bio je istražiti utjecaj različitih vrsta kvasaca na osnovni kemijski sastav, koncentraciju ukupnih fenola i ukupnih antocijana voćnih vina od šljive. Korištene su dvije različite vrste kvasaca Lalvin ICV D21 – Saccharomyces cerevisiae i Lalvin EC 1118 – Saccharomyces bayanus. Vina proizvedena aktivnošću kvasca ICV D21 imala su viši sadržaj alkohola, ekstrakta te ukupnih fenola i ukupnih antocijana. Rezultati ovog istraživanja ukazuju na značajan utjecaj vrste kvasca na kemijski sastav i kakvoću voćnih vina od šljive.
Plum (Prunus domestica L.) is highly valued drupe because of its desirable sensory and nutritional properties. The fruits are consumed fresh or processed. The fruits of the ´Stanley´ variety are a good choice for the production of fruit wines due to their relatively high sugar content and lower total acidity. Fruit wines are produced by yeasts in the process of alcoholic fermentation. Yeast metabolism produces a
number of metabolites, so we influence the type of the wine by choosing the appropriate strain. The aim of this study was to determine the influence of different yeast strains on the basic chemical composition, concentration of total phenols and total anthocyanins of plum fruit wines. Two different commercial yeasts were used, Lalvin ICV D21 - Saccharomyces cerevisiae and Lalvin EC 1118 - Saccharomyces bayanus. Wines produced under the influence of yeast ICV D21 had a higher content of alcohol, extract, total phenols and total anthocyanins. The obtained results of the research indicate a significant impact of yeast strains on the chemical composition and quality of plum fruit wines
Cilj rada bio je analizirati i usporediti nutritivnu kvalitetu mutnih, svježe cijeđenih sokova iz plodova četiriju različitih sorti jabuka: 'Idared', 'Jonagold', 'Golden Delicious' i 'Cripps Pink'. S ...obzirom na analizirani mehanički sastav utvrđeno je da najbolje iskorištenje ploda za dobivanje soka ima sorta 'Idared' (45,51%), zatim slijedi sorta 'Golden Delicious (44,22%), 'Jonaglod' (36,56%) te sorta 'Cripps Pink' (25,75%). Prema rezultatima dobivenim u ovom istraživanju sok sorte 'Golden Delicious' pokazuje najveći omjer TST/UK, zatim sok sorte 'Jonagold', 'Idared', dok je najmanji omjer utvrđen kod soka sorte 'Cripps Pink'. Najveći sadržaj vitamina C (6,75 mg/100g svježeg ploda) kao i najveći sadržaj ukupnih fenola (55,84 mgGAE/100 g svježe tvari) utvrđeni su u soku sorte 'Jonagold' Temeljem dobivenih rezultata može se zaključiti da su plodovi svih istraživanih sorti pogodni za proizvodnju mutnog soka, ali i da mogu biti dobra podloga za proizvodnju ostalih sokova od raznih vrsta voća
The aim of the study was to analyse and compare the nutritional quality of cloudy, freshly squeezed fruit juices from four different apple cultivars: ‘Idared’, ‘Jonagold’, ‘Golden Delicious’ and ‘Cripps Pink’. Considering the analysed mechanical composition, it was determined that the best yield of fruit for juice production has the cultivar 'Idared' (45.51%), followed by the cultivar ‘Golden Delicious’ (44.22%), 'Jonaglod' (36.56%) and the 'Cripps Pink' cultivar (25.75%). According to the results obtained in this study, the juice of the 'Golden Delicious' cultivar shows the highest TST/UK r atio, followed b y t he j uice o f t he 'Jonagold' a nd 'Idared' cultivars, while the lowest ratio was found for the juice of the 'Cripps Pink' cultivar. The highest content of vitamin C was determined in the juice of the cultivar 'Jonagold' (6.75 mg/100 g of fresh fruit) as well as the highest content of total phenols (55.84 mg GAE/100 g of fresh matter). Based on the obtained results, it can be concluded that the fruits of all investigated cultivars are suitable for the production of cloudy juice, but also that they can be a good base for the production of juices from various types of fruit.
Strawberry tree (
L.) honey (STH), also known as “bitter honey”, is a traditional medicine widely used in the Mediterranean area. Regardless of geographical origin, it usually has a very high content ...of phenolic compounds and strong antioxidant capacity. Yet, little is still known about the effects of STH, its phenolic extract (STHE), and its main bioactive compound – homogentisic acid (HGA) – at the cell level. The aim of this study was to estimate total phenolic content, DPPH radical scavenging activity, and ferric reducing antioxidant power of STH made in Croatia and investigate cytotoxic and pro-oxidative effects of STH, STHE and HGA on three human cell lines: tongue squamous cell carcinoma (CAL 27), hepatocellular carcinoma (HepG2), and epithelial colorectal adenocarcinoma cells (Caco-2) cells. These substances were tested at four concentrations (0.5–5× average human daily intake of STH) and over 30 min and 1 and 2 h. Croatian STH had a total phenolic content of 1.67 g gallic acid equivalents (GAE) per kg of honey, DPPH radical scavenging activity of 2.96 mmol Trolox equivalents (TE) per kg of honey, and ferric reducing antioxidant power (FRAP) of 13.5 mmol Fe
per kg of honey. Our results show no clear and consistent time- or concentration-dependent cytotoxicity in any of the cell lines. ROS levels in all the three cell types at almost all exposure times were not significantly higher than control. The most important observation is that the tested substances have low cytotoxicity and high biocompatibility, regardless of concentration, which is a good starting point for further research of their biological effects in other models.
Bor (B) je esencijalni biogeni element neophodan za rast i razvoj masline, a nedostatak B općenito se smatra jednim od najčešćih nedostataka mikroelemenata u maslinarstvu. Iako nedostatak B može ...dovesti do promjene koncentracije različitih fenolnih spojeva u listu masline utjecaj ishranjenosti masline B na fenolni profil lista udomaćenih sorata masline nije dovoljno istražen. Stoga, cilj ovog istraživanja bio je utvrditi utjecaj primjene hranive otopine s (B+) (30 μM B) ili bez (B-) (0 μM B) bora na fenolni profil lista masline (Olea europaea L.) sorte 'Istarska bjelica'. Pokus je postavljen kao slučajni blokni raspored u četiri ponavljanja na ukupno 40 sadnica masline sorte 'Istarska bjelica'. Uzorkovanje lista provedeno je nakon 60 dana od početka pokusa. Koncentracija B u listu masline bila je značajno veća u B+ tretmanu, dok su utvrđene koncentracije ukupnih fenola i verbaskozida u listu masline bile značajno veće u B- tretmanu. Gnojidba B nije značajno utjecala na koncentraciju ostalih fenolnih spojeva. Značajno veća koncentracija ukupnih fenola i verbaskozida u listu sorte 'Istarska bjelica' kod B- tretmana može se povezati s fiziološkim odgovorom biljke na nedostatak B.
Boron (B) is an essential nutrient for growth and development of olive, whereas B deficiency is among the most common micronutrient disorders in
olive production. Boron deficiency contributes changes in the concentration of different phenolic compounds in olive leaves, the impact of B nutrition on the phenolic leaf profile of autochthonous olive varieties is mainly unknown. This study aimed to investigate the impact of nutrient solutions, with (B+) and without (B-) boron addition,
on the phenolic profile in olive leaves of cultivar ‘Istarska bjelica’.
The experiment was set up in random block design in four repetitions, on 40 olive plantlets of cultivar ‘Istarska bjelica’. Olive leaves were sampled 60 days after the beginning of the experiment. Boron concentration in olive leaves was significantly higher in the B+ treatment, whereas total phenolic content and verbascoside concentration
were significantly higher in the olive leaves of the B- treatment. Boron nutrition had no significant impact on other phenolic compounds. A
significantly higher total phenolic content and verbascoside concentration, determined in olive leaves of cultivar ‘Istarska bjelica’, indicate the relation between physiological plant response and
B deficiency.
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