29 research outputs found
Comparison of the characteristics of grape varieties Babica and Tribidrag
Vinogorje KaÅ”telaāTrogir je podruÄje uzgoja mnogih autohtonih sorti vinove loze. Od crnog sortimenta najzastupljenija je sorta Babica. Nakon Å”to je DNK analizom utvrÄena genetska istovjetnost kalifornijskog Zinfandela, te talijanskog Primitiva s Tribidragom zapoÄinje njegova revitalizacija. Iz komercijalnih razloga povrÅ”ine pod Tribidragom se poveÄavaju, 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 viÅ”e Å”to sve moguÄnosti njenog enoloÅ”kog potencijala nisu u potpunosti iskoriÅ”tene.In the vineyard area of KaÅ”tela ā 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 kakvoÄe (tip cognac) vinskih destilata upravo taj fenomen ima dominirajuÄu, a vrlo Äesto i odluÄujuÄu ulogu. Na aromu vinskih destilata utjeÄe mnogo Äinitelja tijekom njezina stvaranja u tehnoloÅ”kom procesu proizvodnje. MeÄutim, objektivnu je prosudbu o utjecaju pojedinog Äinitelja iznimno teÅ”ko donijeti jer aroma ima i subjektivni karakter. U ovom je radu ispitana moguÄnost objektivne procjene utjecaja sorte na aromu vinskih destilata primjenom raÄunala u obradbi kromatografskih rezultata analize tvari arome, a navedeni su rezultati provjereni senzorskim analizama. Dobiveni su rezultati pokazali da se matematiÄki model za kompjutorsko izraÄunavanje sliÄnosti kromatograma arome može uspjeÅ”no koristiti pri objektivnoj procjeni utjecaja pojedinih Äinitelja na aromu vinskih destilata, te da sorta grožÄa bitno utjeÄe na aromu i kakvoÄu vinskih destilata
ANALIZA INTERNE KOMUNIKACIJE VIRTUALNIH TIMOVA
Sve viÅ”e tvrtki svoje poslovanje premjeÅ”ta u virtualni prostor, Å”to donosi nove izazove u svakodnevnom funkcioniranju timova. U ovom radu ispitan je 41 Älan osam razliÄitih virtualnih timova unutar informatiÄke tvrtke. Anketni upitnik od 35 pitanja, kreiran temeljem prijaÅ”njih istraživanja, mjerio je razliÄite aspekte rada virtualnih timova, podijeljene u Äetiri glavne skale - komunikacijska mreža, stavovi o radu virtualnih timova opÄenito, izazovi prilikom sastanaka virtualnih timova i procjena uÄinkovitosti vlastitih virtualnih timova. U radu su provjerene dvije glavne hipoteze - 1. jesu li uÄinkovitiji oni virtualni timovi kod kojih postoji jasna komunikacijska mreža i 2. jesu li uÄinkovitiji oni timovi kod kojih Älanovi imaju opÄenito pozitivne stavove o virtualnim timovima. Obje hipoteze dobile su statistiÄku potvrdu. Provjerena je i povezanost ostalih skala upitnika, kao i povezanost broja Älanova tima s rezultatima na Äetiri skale upitnika. Na temelju dobivenih rezultata generirani su zakljuÄci i praktiÄne preporuke
Influence of laccase and polyvinylpyrrolidone on the quality and phenolic composition of LaŔki Riesling wine
Fenolni spojevi su poželjan sastojak vina zbog njihovog dobro poznatog pozitivnog uÄinka na zdravlje ljudi, meÄutim zbog podložnosti oksidaciji, mogu negativno utjecati na boju, stabilnost te ukupnu kvalitetu bijelih vina. Sumporni dioksid, uÄinkovit antioksidans koji se koristi za stabilizaciju i sprjeÄavanje posmeÄivanja, izbjegava se zbog moguÄeg Å”tetnog 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 sprjeÄava njihovu oksidaciju. Nasuprot tome, enzim lakaza katalizira oksidaciju fenolnih spojeva te ubrzava nastajanje visokomolekularnih smeÄe obojenih polimera koji se uklanjaju odgovarajuÄim postupcima filtracije vina. Na taj naÄin se sprjeÄava naknadna oksidacija fenolnih spojeva te posmeÄivanje i zamuÄenje 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 LaÅ”ki 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 znaÄajno utjecali na fizikalno-kemijska svojstva, a poboljÅ”ali 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 oÄuvanja boje i kvalitete bijelog vina LaÅ”ki 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 LaÅ”ki 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 LaÅ”ki 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 Zagrebās 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 mlijeÄnim proizvodima. Na udjel minerala u mlijeku utjeÄu mnogi faktori, od uvjeta zaÅ”tite okoliÅ”a za vrijeme ispaÅ”e, 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 PreporuÄene dnevne unose (RDA), Adekvatne unose (AIs) ili Maksimalno dozvoljene dnevne unose (Uls) za esencijalne elemente. Analizirani su uzorci mlijeka razliÄitih proizvoÄaÄa, s razliÄitim udjelom masti, a nabavljeni su na zagrebaÄkom tržiÅ”tu Äetiri puta tijekom 2007. godine. Udjeli deset minerala (Ca, P, Mg, Fe, Cu, Zn, Mn, Ni, K and Na) odreÄeni
su pomoÄu atomske apsorpcijske spektrometrije. Srednje vrijednosti udjela minerala bile su u skladu s literaturnim podacima. TakoÄer je procijenjen dnevni unos navedenih minerala putem mlijeka, kod djece Å”kolskog uzrasta (Å”kolska djeca u dobi 8-9 godina i adolescenti u dobi 15-18 godina) podijeljene u grupe obzirom na godine i spol. ProsjeÄni 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 karakteristiÄna oblika individualnih zrna veliÄine 3-12 mm. Može se koristiti kao dijetni sir, zbog minimalne koliÄine mlijeÄne masti (ali, bogat je bjelanÄevinama), ili kao "krem" sir, ako se prekrije nekom krem mjeÅ”avinom, najÄeÅ”Äe od vrhnja, uz razliÄite dodatke (sol, povrÄe, voce i sliÄno). BuduÄi da se Cottage sir joÅ” uvijek ne proizvodi u Hrvatskoj, svrha ovog rada je ispitati prihvatljivost ovog proizvoda, nepoznatog veÄini potroÅ”aÄa u naÅ”oj 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 gruÅ”a u slanoj otopini, kao i prihvatljivost razliÄitih uzoraka Cottage sira pomijeÅ”anog mjeÅ”avinom vrhnja i razliÄitih dodataka - Krem Cottage sir. Testirano je 40 potroÅ”aÄa (starih 20-60 godina). Oni su pripremljene uzorke Cottage sira ocijenili hedonistiÄkom skalom Peryama (moguÄa ocjena 1-9), najÄeÅ”Äom 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 odreÄivanju 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 + Īµ. 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 moguÄnost primjene nedestruktivnih metoda za odreÄivanje suhe tvari sirutke. KoriÅ”tene su slijedeÄe nedestruktivne metode: infracrvena spektroskopija, krioskopija i mjerenje elektroprovodljivosti, a kao referentna koriÅ”tena je gravi-metrijska metoda. StatistiÄkom obradom rezultata utvrÄen je stohastiÄki odnos izmeÄu nezavisne varijable (provjeravana metoda) i zavisne varijable (referentna metoda). StohastiÄki odnos pokazao je zadovoljavajuÄu ovisnost varijabli linearnom funkcijom oblika Y=b0x0+b1x1+Īµ. Efikasnost modela je provjerena koeficijentom determinacije. Infracrvena spektroskopija i krioskopija bile su uspjeÅ”ne metode za odreÄivanje suhe tvari sirutke. Rezultati dobiveni mjerenjem elektroprovodljivosti manje su precizni