Comparison of the characteristics of grape varieties Babica and Tribidrag

Vinogorje Kaštela–Trogir je područje uzgoja mnogih autohtonih sorti vinove loze. Od crnog sortimenta najzastupljenija je sorta Babica. Nakon što je DNK analizom utvrđena genetska istovjetnost kalifornijskog Zinfandela, te talijanskog Primitiva s Tribidragom započinje njegova revitalizacija. Iz komercijalnih razloga površine pod Tribidragom se povećavaju, a Babice i ostalih sorti opadaju. Dok se zadnjih godina pojavljuju neke nove okolnosti koje otežavaju uzgoj Tribidraga, Babica zaslužuje biti predmetom vinogradarskog interesa, tim više što sve mogućnosti njenog enološkog potencijala nisu u potpunosti iskorištene.In the vineyard area of Kaštela – Trogir many autochthonous grapevine cultivars are cultivated. Among red wine cultivars Babica cultivar has been mostly represented. After DNA analysis proved that Tribidrag is genetically identical with Californian Zinfandel and Italian Primitivo cultivars, its revitalisation has begun. Because of commercial reasons Tribidrag grape growing areas have been increasing while those cultivating Babica and other grape varieties have been gradually decreasing. It has been observed that recently some new difficulties in cultivation of Tribidrag cultivar have appeared, whereas Babica deserves to become the focus of vine growing interest as all the possibilities of its enological potential are not fully exploited

Utjecaj vinskih sorta na aromu destilata

Aroma is a phenomenon that occurrs when food and live organism mutually react during the process of consumption. Many factors influence the making of aroma of wine distillates (e.g. cognac) during the technological process of distillation. It is extremely difficult to bring an objective judgement on the influence of individual factors since aroma is very subjective in its nature. The possibility of objective assessment of the influence of grape varieties on wine distillate was performed in this work using a computer in processing the results of cromatographic analyses of aroma substances. The given results were verified by sensor analyses. The achieved results have shown that mathematical model for calculating aroma chromatogram similarity can be successfully used for objective assessment of the influence of individual factors on aroma of wine distillates and that grape varieties have significant impact on aroma and the quality of wine distillates.Aroma je fenomen koji se pojavljuje tijekom konzumiranja hrane u organizmu. Pri stvaranju ukupne kakvoće (tip cognac) vinskih destilata upravo taj fenomen ima dominirajuću, a vrlo često i odlučujuću ulogu. Na aromu vinskih destilata utječe mnogo činitelja tijekom njezina stvaranja u tehnološkom procesu proizvodnje. Međutim, objektivnu je prosudbu o utjecaju pojedinog činitelja iznimno teško donijeti jer aroma ima i subjektivni karakter. U ovom je radu ispitana mogućnost objektivne procjene utjecaja sorte na aromu vinskih destilata primjenom računala u obradbi kromatografskih rezultata analize tvari arome, a navedeni su rezultati provjereni senzorskim analizama. Dobiveni su rezultati pokazali da se matematički model za kompjutorsko izračunavanje sličnosti kromatograma arome može uspješno koristiti pri objektivnoj procjeni utjecaja pojedinih činitelja na aromu vinskih destilata, te da sorta grožđa bitno utječe na aromu i kakvoću vinskih destilata

ANALIZA INTERNE KOMUNIKACIJE VIRTUALNIH TIMOVA

Sve više tvrtki svoje poslovanje premješta u virtualni prostor, što donosi nove izazove u svakodnevnom funkcioniranju timova. U ovom radu ispitan je 41 član osam različitih virtualnih timova unutar informatičke tvrtke. Anketni upitnik od 35 pitanja, kreiran temeljem prijašnjih istraživanja, mjerio je različite aspekte rada virtualnih timova, podijeljene u četiri glavne skale - komunikacijska mreža, stavovi o radu virtualnih timova općenito, izazovi prilikom sastanaka virtualnih timova i procjena učinkovitosti vlastitih virtualnih timova. U radu su provjerene dvije glavne hipoteze - 1. jesu li učinkovitiji oni virtualni timovi kod kojih postoji jasna komunikacijska mreža i 2. jesu li učinkovitiji oni timovi kod kojih članovi imaju općenito pozitivne stavove o virtualnim timovima. Obje hipoteze dobile su statističku potvrdu. Provjerena je i povezanost ostalih skala upitnika, kao i povezanost broja članova tima s rezultatima na četiri skale upitnika. Na temelju dobivenih rezultata generirani su zaključci i praktične preporuke

Influence of laccase and polyvinylpyrrolidone on the quality and phenolic composition of Laški Riesling wine

Fenolni spojevi su poželjan sastojak vina zbog njihovog dobro poznatog pozitivnog učinka na zdravlje ljudi, međutim zbog podložnosti oksidaciji, mogu negativno utjecati na boju, stabilnost te ukupnu kvalitetu bijelih vina. Sumporni dioksid, učinkovit antioksidans koji se koristi za stabilizaciju i sprječavanje posmeđivanja, izbjegava se zbog mogućeg štetnog utjecaja na zdravlje ljudi i kvalitetu vina. Stoga se koriste i istražuju druga sredstva kao npr. polivinilpolipirolidon (PVPP) i lakaza. PVPP je sintetski polimer koji veže fenolne spojeve i time sprječava njihovu oksidaciju. Nasuprot tome, enzim lakaza katalizira oksidaciju fenolnih spojeva te ubrzava nastajanje visokomolekularnih smeđe obojenih polimera koji se uklanjaju odgovarajućim postupcima filtracije vina. Na taj način se sprječava naknadna oksidacija fenolnih spojeva te posmeđivanje i zamućenje vina. S tim u vezi cilj istraživanja bio je ispitati utjecaj tretmana PVPP-om ili lakazom na fizikalno-kemijska svojstva (udjeli etanola, ukupnog ekstrakta, hlapljivih i nehlapljivih kiselina, pH-vrijednost, intenzitet boje), senzorsku kvalitetu i koncentraciju pojedinih skupina fenolnih spojeva (flavonoidi, neflavonoidi, kondenzirani tanini, leukoantocijani) bijelog vina Laški rizling. Finalizacija netretiranog (kontrolnog) vina i vina tretiranih PVPP-om odnosno lakazom provedena je ultrafiltracijom. Odabrani uvjeti tretmana, provjereni su brzim testiranjem u laboratorijskim uvjetima: aroma je u vinu ostala nepromijenjena, a masena koncentracija koloida je smanjena. Stoga su isti uvjeti tretmana primijenjeni u industrijskom mjerilu te uglavnom nisu značajno utjecali na fizikalno-kemijska svojstva, a poboljšali su senzorsku kvalitetu tretiranih vina. Smanjili su koncentracije svih skupina fenolnih spojeva i rezultirali manjim intenzitetom boje tj. svjetlijom bojom tretiranih od kontrolnog vina. Dobiveni rezultati ukazuju na prikladnost PVPP-a i lakaze u postupcima očuvanja boje i kvalitete bijelog vina Laški rizling.Phenolic compounds, with their well known positive effect on human health, are a desirable constituent of wine, however, due to their susceptibility to oxidation, they can negatively affect the color, stability and overall quality of white wines. Sulphur dioxide, the effective antioxidant used for wine browning prevention and stabilization, is avoided cause of possible harmful effect on human health and wine quality. Therefore, other agents such as polyvinylpolypyrrolidone (PVPP) and laccase are used, and investigated as well still , too. PVPP ( a synthetic polymer) binds phenolic compounds and thus prevents their oxidation. In contrast, the enzyme lacase catalyzes the oxidation of phenolic compounds and accelerates the formation of high molecular weight brown polymers which are removed in finalization processes such as ultrafiltration. In this way, the subsequent oxidation of phenolic compounds as well as wine browning and turbidity are prevented. Considering the above facts, the aim of this study was to examine the effectiveness of treatment with PVPP or laccase, combined with ultrafiltration, on the physicochemical properties (contents of ethanol, total extract, volatile and non-volatile acids, pH value, color intensity), sensory quality and the concentration of individual groups of phenolic compounds (flavonoids, neflavonoids, condensed tannins, leukoanthocyanidins) of Laški Riesling white wine. Finalization of untreated (control) wine and wines treated with PVPP or laccase and treated wines was performed by ultrafiltration. The selected experimental conditions were previously tested in laboratory scale and confirmed that colloid content was reduced by treatments with PVPP or laccase. while wine aroma was not significantly impaired. Further, the same treatments were applied in the industrial conditions and according to obtained results they did not significantly affect the basic physicochemical properties, but improved the sensory quality of the treated wines. Therefore, the same treatment conditions were applied in industrial scale and generally did not significantly affect the physico-chemical properties, while the sensory quality of the treated wines were improved. The concentrations of all groups of phenolic compounds and color intensities were reduced in the treated wines when compared to color control wine. The obtained results indicate the suitability of both PVPP and laccase in the processes of stabilization and color preservation of white wine Laški Riesling

Esencijalni minerali mlijeka i njihov dnevni unos konzumiranjem mlijeka

Minerals occur in all foodstuffs as well as in milk and dairy products. The mineral content in milk is influenced by many factors ranging from environmental conditions during pasture, feeding, breeding, stage of lactation and climate to post-milking handling, transportation and processing. The aim of the study was to assess whether the intakes comply with Recommended Dietary Allowances (RDA), Adequate Intakes (AIs) or Tolerable Upper Intake Levels (ULs) for essential elements. Milk samples from different producers and with different fat content were purchased from Zagreb’s market four times in year 2007 and analysed. Concentrations of ten minerals (Ca, P, Mg, Fe, Cu, Zn, Mn, Ni, K and Na) were determined by atomic absorption spectrometry. Mean values of mineral contents were in range with the literature data. The daily intakes of these minerals by school children selected in age-gender groups (school children 8-9 years old and adolescents 15-18 years old) through milk consumption were also estimated. The average daily intake of essential minerals ranged from a minimum of 1.36 % of manganese up to 35.27 for phosphorus, irrespective of age and gender of children.Minerali se nalaze u svim namirnicama pa tako i u mlijeku i mliječnim proizvodima. Na udjel minerala u mlijeku utječu mnogi faktori, od uvjeta zaštite okoliša za vrijeme ispaše, hranjenja, uzgoja, stadija laktacije i klime do postupaka nakon mužnje, transporta i obrade. Cilj istraživanja bio je procijeniti je li unos esencijalnih minerala u skladu s vrijednostima za Preporučene dnevne unose (RDA), Adekvatne unose (AIs) ili Maksimalno dozvoljene dnevne unose (Uls) za esencijalne elemente. Analizirani su uzorci mlijeka različitih proizvođača, s različitim udjelom masti, a nabavljeni su na zagrebačkom tržištu četiri puta tijekom 2007. godine. Udjeli deset minerala (Ca, P, Mg, Fe, Cu, Zn, Mn, Ni, K and Na) određeni su pomoću atomske apsorpcijske spektrometrije. Srednje vrijednosti udjela minerala bile su u skladu s literaturnim podacima. Također je procijenjen dnevni unos navedenih minerala putem mlijeka, kod djece školskog uzrasta (školska djeca u dobi 8-9 godina i adolescenti u dobi 15-18 godina) podijeljene u grupe obzirom na godine i spol. Prosječni dnevni unosi esencijalnih minerala kretali su se od minimalno 1,36 % za mangan do maksimalno 35,27 % za fosfor, bez obzira na dob i spol djece

Sensory properties and acceptability of Cottage cheese

Cottage sir je svježi sir karakteristična oblika individualnih zrna veličine 3-12 mm. Može se koristiti kao dijetni sir, zbog minimalne količine mliječne masti (ali, bogat je bjelančevinama), ili kao "krem" sir, ako se prekrije nekom krem mješavinom, najčešće od vrhnja, uz različite dodatke (sol, povrče, voce i slično). Budući da se Cottage sir još uvijek ne proizvodi u Hrvatskoj, svrha ovog rada je ispitati prihvatljivost ovog proizvoda, nepoznatog većini potrošača u našoj zemlji. Uzorci Cottage sira proizvedeni su od obranog ili UF-obranog mlijeka (s oko 5 i 7% proteina) a tada, nakon ocjenjivanja senzorskih svojstava, oblikovani u zrna boljih karakteristika, koristili su se za pripravu uzoraka Krem Cottage sira. U radu je ispitana prihvatljivost slanih zrnaca Cottage sira proizvedenih ispiranjem gruša u slanoj otopini, kao i prihvatljivost različitih uzoraka Cottage sira pomiješanog mješavinom vrhnja i različitih dodataka - Krem Cottage sir. Testirano je 40 potrošača (starih 20-60 godina). Oni su pripremljene uzorke Cottage sira ocijenili hedonističkom skalom Peryama (moguća ocjena 1-9), najčešćom metodom za istraživanje prihvatljivosti prehrambenih proizvoda.Cottage cheese is soft fresh cheese having characteristically shaped individual granules of approximately 3-12 mm. Cheese may be used such as dietetic food, owning to its minimum milk fat quantity, and having plenty of proteins, or such Creamed Cottage cheese, covered with some creaming mixtures (added salt, fruit, vegetables or something similar). Since Cottage cheese was not as yet produced in Croatia, the purpose of this paper is to investigate consumer\u27s acceptability as it is unknown to many of our consumers. Cottage cheese samples were produced from skim milk and ultrafiltered skim milk (with 5 and 7% proteins) and then shaped as granules of better characteristics, according of sensory properties evaluation, used for preparation of Creamed Cottage cheese. Investigation is relative to the acceptability of Cottage cheese having salty granules and also to acceptability of Cottage cheese samples mixed with sour cream and different ingredients - Creamed Cottage cheese. Consumer\u27s panel of 40 members (from 20 to 60 years old) evaluated Cottage cheese samples using a nine-point Hedonic scale, probably the most useful sensory method

Influence of Blending on the Aroma of Malvasia istriana Wine

Malvasia istriana (Vitis vinifera) is a domestic and widespread grape cultivar in the Istrian wine region that gives the characteristic white wine. Istrian region is situated in the western part of Croatia (Adriatic coast). In the ageing process, Malvasia istriana loses its aroma (freshness and fruitiness) and hence it is usually consumed as a young wine. Therefore, blending is used to improve the quality of Malvasia istriana wine, to enrich its aroma and to maintain its varietal recognizability during the consumption period. Malvasia istriana base wine (85 %) was blended with Chardonnay, Sauvignon blanc, Pinot blanc, Prosecco and Muscat, from grape varieties grown in the Istrian region. The change in volatile compounds of the blends was observed throughout the year by using headspace solid phase microextraction (HS-SPME). Based on the analysis of the volatile compounds and sensory evaluation of the wine quality, the best result was obtained by blending Malvasia istriana with Sauvignon blanc and Pinot blanc. Chardonnay, Pinot blanc, Sauvignon blanc and Prosecco proved to be suitable for blending with Malvasia istriana, giving blends of high quality of the desired aroma profile. Muscat wine blended independently with Malvasia istriana or in combination with other wines proved to be unsuitable for blending due to its specific muscat aroma which dominates over the base wine aroma in the blend. Blending Malvasia istriana with other selected wines produced wines of better sensory quality, richer in volatile compounds, which can justify the blending

Primjena nedestruktivnih metoda analize u određivanju suhe tvari sirutke

Possibility of applying non-destructive methods in determination of whey solids was investigated. The non-destructive methods used were: infrared spectroscopy, cryoscopy, conductometry and gravimetric method as a referent method. With statistical interpretation of results the stochastic relation of variable between independent variable (investigated method) and dependent variable (referent method) was established. The stochastic relation showed satisfactory dependency of variables with linear equation: Y = b0X0 + b1x1 + ε. Determination coefficient verified model\u27s efficacy. Infrared spectroscopy and cryoscopy were successful methods for determination of whey solids. Less precise were conductometry results.U radu je istražena mogućnost primjene nedestruktivnih metoda za određivanje suhe tvari sirutke. Korištene su slijedeće nedestruktivne metode: infracrvena spektroskopija, krioskopija i mjerenje elektroprovodljivosti, a kao referentna korištena je gravi-metrijska metoda. Statističkom obradom rezultata utvrđen je stohastički odnos između nezavisne varijable (provjeravana metoda) i zavisne varijable (referentna metoda). Stohastički odnos pokazao je zadovoljavajuću ovisnost varijabli linearnom funkcijom oblika Y=b0x0+b1x1+ε. Efikasnost modela je provjerena koeficijentom determinacije. Infracrvena spektroskopija i krioskopija bile su uspješne metode za određivanje suhe tvari sirutke. Rezultati dobiveni mjerenjem elektroprovodljivosti manje su precizni