QUALITY OF MUST AND RHINE RIESLING WINE OF KUTJEVO VINEYARD AREA

Količine šećera i kiselina u moštu Rizling rajnski Kutjevačkog vinogorja praćene su u petogodišnjem razdoblju, od 1999.-2003. godine, na obiteljskom gospodarstvu Jakobović. Istraživanja ukazuju na variranje kakvoće moštova i vina zbog klimatskih uvjeta pojedine godine. Posebno se izdvajaju godine 2000. i 2003. godina, kada su količine šećera bile izrazito visoke, a sadržaj ukupnih kiselina znatno niži, što se kasnije odrazilo i na količine alkohola i kiselina u vinu, kao i na organoleptiku vina.Quantities of sugar and acid in the must of Riesling Rhine of Kutjevo vineyard area were observed on the Jakobovic Family Estate in the period of five years, from 1999 to 2003. The analysis shows varying quality of must and wine due to climatic conditions of a particular year. In the year 2000 and 2003 the quantities of sugar were exceptionally high and the content of all acids considerably lower which reflected later on the quantity of alcohol and acid in wine, as well as on organoleptic traits of wine

IMPACT OF GRAPE POMACE MACERATION ON THE QUALITY OF RHINE RIESLING WINE

Vina Rajnskog rizlinga proizvedena standardnom tehnologijom za bijela vina te maceracijom masulja od 3 sata i maceracijom masulja od 6 sati analizirana su kako bi se utvrdile razlike u kemijskom sastavu i senzornim svojstvima. Kemijska analiza provedena je nakon fermentacije, a senzorno ocjenjivanje 3 mjeseca nakon fermentacije. Vina dobivena maceracijom masulja od 3 sata senzorno su ocijenjena najbolje dok su vina dobivena maceracijom od 6 sati te standardnom tehnologijom bila slabije kakvoće. Po kemijskom sastavu vina dobivena maceracijom masulja nisu se međusobno razlikovala, dok su vina dobivena standardnim postupkom proizvodnje za bijela vina imala niži ukupni ekstrakt, pepeo, hlapivu kiselost i ukupne fenole.Rhine riesling wines produced by usual technology for white wines and by maceration for 3 hours and maceration for 6 hours were investigated for differences in chemical composition and sensory properties. Chemical analyses were performed after fermentation and sensory testing was done 3 months after fermentation. Wine produced by maceration for 3 hours was evaluated as sensory the best while the wine produced by maceration for 6 hours and usual technology was of inferior quality. In chemical composition there was no difference between wine produced by maceration of grape pomace while wines produced by standard technology for white wine had lower total extract, ashes, volatyle acidity and total phenols

Aminokiselinski sastav mošta nekih sorata vinove loze (Vitis vinifera L.) Hrvatske

Free amino acids in grape juice are important as nitrogen source for yeast strains during alcoholic fermentation. The aim of this research was to determine amino acid profiles in musts from nine grapevine cultivars (six white and three red). The cultivars were located in a homogeneous soil and climatic zone of Bilogora growing hill (West continental region, Prigorje–bilogora subregion), grown on the same training system. The experiment was conducted in vintage 2015. The results showed significant influence of grape cultivar on the amino acids composition in musts of white and red grape cultivars. Arginine was dominant in most analyzed varieties of amino acids. The highest concentration of arginine in white cultivars was measured in Chardonnay must (470.18 mg/L) and in red cultivar must from Saint Laurent (280.65 mg/L). Statistically significant difference was also found in the total amino acid composition of white and red cultivars. The highest concentration of total amino acids in white cultivars was determined in Manzoni juice (1639.51 mg/L) and among the red cultivars in Pinot noir juice (1173.12 mg/L).Slobodne aminokiseline u moštu su važan izvor dušika za kvasce tijekom alkoholne fermentacije. Cilj ovog istraživanja bio je odrediti aminokiselinski profil mošteva devet sorata vinove loze (šest bijelih i tri crne). Sorte vinove loze zasađene su u ujednačenim uvjetima tla i klime vinogorja Bilogora (Regija Kontinentalne Hrvatske, podregija Prigorje-bilogora) te su imale iste agrotehničke uvjete uzgoja. Pokus je postavljen 2015. godine. Rezultati su pokazali signifikantan utjecaj sorte na aminokiselinski sastav u moštevima bijelih i crnih sorti. Najzastupljenija aminokiselina u moštevima devet sorata vinove loze bila je arginin. Najveća koncentracija arginina kod bijelih sorata bila je u moštu Chardonnay (470,18 mg/l), a kod crnih sorata u moštu Lovrijenca (280,65 mg/l). Statistički značajne razlike nađene su između koncentracije ukupnih aminokiselina bijelih i crnih sorata. Najveća koncentracija ukupnih aminokiselina kod bijelih sorata bila je u moštu sorte Manzoni (1639,51 mg/l), a kod crnih sorata u moštu sorte Pinot crni (1173,12 mg/l

GRAPE MATURITY OF RHEIN RIESLING CULTIVAR AND SYNTHESIS OF ATYPICAL AGEING AROMA PRECURSORS

Istraživanja formiranja netipične arome starenja vina (UTA) otkrila su značajnu korela¬ciju između UTA, koncentracije 2-aminoacetofenona (AAP) i vina dobivena od grožđa, koje je bilo pod utjecajem stresa (nedostatak vode ili opskrbe dušikom), vina od grožđa iz vinograda s visokim prinosima ili od ranije branoga grožđa. Cilj ovog istraživanja bio je istražiti različitu dozrelost grožđa i sintezu indol-3-octene kiseline i triptofana u moštu i vinu kod bijeloga kultivara vinove loze Rizling rajnski (Vitis vinifera L.). Tretmani u istraživanju bili su dva roka berbe grožđa (redovna i kasna berba) s dva različita položaja (Mladice i Hrnjevac). Indol-3-octena kiselina i triptofan u moštu i vinu određeni su metodom tekućinskom kromatografijom visoke djelotvornosti, uz fluore¬scentni detektor. Dozrijevanjem grožđa koncentracije indol-3-octene kiseline i tripto-fana smanjivale su se nezavisno od godine istraživanja te ispitivanoga položaja. Vina dobivena od kasnije branoga grožđa imaju manju mogućnost pojave netipične arome starenja vina u odnosu na ona redovne berbe.The research on forming atypical aging off-flavor in wines (UTA) was revealed a significant correlation between the UTA , the concentration of 2-aminoacetophenones (AAP) and the wines produced from grapes affected by stress (lack of water or nitrogen supply), wines from grapes grown in high yielding vineyards or earlier harvested grapes. The aim of this study was to explore the different grape ripeness and synthesis of indole-3-acetic acid and tryptophan in must and wine of white cultivar Rhine Rieslin (Vitis vinifera L.). Treatments in the research have been the two periods of the grape harvesting dates (regular and late harvesting) from two different locations (Mladice and Hrnjevac). Indole-3-acetic acid and tryptophan in must and wine were determined by high performance liquid chromatography with fluorescence detector. As the process of ripening was going on the concentration of indole-3-acetic acid and tryptophan in must and wines have been reduced regardless the year of research and vineyards positions. Wines produced from late harvested grapes have a lower possibility of the appearance of atypical aroma aging effect compared to the regular harvest

RISK MANAGEMENT OF FRUIT, GRAPE AND WINE PRODUCTION FARMS IN SLAVONIA AND BARANYA

Rad prikazuje rezultate anketnog ispitivanja o percepcijama rizika i upravljanju rizikom na voćarskim i vinogradarsko-vinarskim gospodarstvima Slavonije i Baranje. Najvažniji izvor rizika je briga za zdravlje članova gospodarstva, a sljede klimatski čimbenici i skupina tržišnih rizika. Po važnosti strategija za upravljanje rizikom, na prvom je mjestu primjena odgovarajuće tehnologije proizvodnje. Zamjetan je jaz između ocjene važnosti poljoprivrednog osiguranja i njegove primjene na gospodarstvu. Na temelju dobivenih rezultata, daljnji je tijek istraživanja usmjeren na utvrđivanje učinkovitog skupa strategija za upravljanje rizikom, koje će doprinijeti optimalizaciji odnosa između rizika i premije na preuzeti rizik u voćarskoj i vinogradarskoj proizvodnji.The Paper presents survey result on risk perceptions and risk management strategies between winemaker and fruits grower in Slavonia and Baranya. Major source of risk are health concerns. Climate factors rank second followed by the market risks. Adequate technology is the most important risk management strategy. Gap between crop insurance\u27s importance and its implementation is evident. Based on the results, the forth coming research will be aimed toward determining efficient set of risk management strategies which should enable optimal relationship between risks and profits in horticulture

Absolute land rent and revaluation of the price of agricultural land in the Republic of Croatia and more particularly in Slavonia and Baranja Concept and Compendium

Prezentacija idejnog koncepta ovoga rada iznijeta je u sklopu znanstvenostručnog skupa Zavoda za znanstveni i umjetnički rad Hrvatske akademije znanosti i umjetnosti u Požegi posvećenog požeškom đaku prof. dr. sc. Branku Štanclu, uglednom profesoru agrarne ekonomike Agronomskog fakulteta Sveučilišta u Zagrebu te dopisnom članu Akademije. Ovaj rad ima za cilj elaborirati i predstaviti razloge, odnosno metodologiju za izračun fer cijene poljoprivrednog zemljišta kroz kapitaliziranu poljoprivrednu zemljišnu rentu. Ova metodologija primjenjiva je kao aktuarski obrazac za izračun spomenute cijene, i to kao indicirane vrijednosti poljoprivrednog zemljišta, odnosno njezina „epicentralna točka“ za prometovanje i menadžment poljoprivrednim zemljištem. Svakako, iz vlasnički razumljivih razloga, ovaj koncept kao „obligacijski“ može biti primjenjiv samo za državno zemljište kojim raspolaže Republika Hrvatska. Isto tako prometovanje poljoprivrednim zemljištem, obiteljskih poljoprivrednih gospodarstava (OPG-a) ne bi smjelo biti cjenovno niže evaluirano od metodološki izračunate fer cijene u sustavu prvokupa od Republike Hrvatske. U radu je primijenjena metoda kapitaliziranja apsolutne zemljišne rente, a kao osnovica za revalorizaciju sadašnje cijene izračuna fer cijena korišteni su podatci iz Pravilnika o načinu revalorizacije zakupnine (NN 65/2019 - 5. 7. 2019.). Posebice smo željeli usporediti cijene po pojedinim županijama RH s istima u pet županija Slavonije i Baranje. Ovim izračunom nisu evaluirani fizikalno-kemijski elementi vrednovanja poljoprivrednog zemljišta, pri čemu bi se trebalo koristiti dodatne elemente iz metodologije FAOa. Premda se ovakav pristup čini netržišnim, on je prihvatljiv jer je narav poljoprivrednog zemljišta takva da se njegova fer cijena ne može podvesti pod klasičnu „formulu“ djelovanja tržišnog mehanizama. Također, u radu su komparirane cijene poljoprivrednog zemljišta, ali i trendovi istih u zemljama članicama EU-a s onima iz Republike Hrvatske za razdoblje od 2013. do 2020. godine.The concept of this research paper was presented at the scientific conference that was held at the Institute for Scientific Research and Artistic Work in Požega and dedicated to a Požega pupil, prof. dr. sc. Branko Štancl, a distinguished professor of the agricultural economics at the Faculty of Agronomy in Zagreb and the corresponding member of the Academy. The goal of this research paper is to elaborate and present the arguments, i. e. methodology for calculating a fair price for agricultural land, by means of the capitalised agricultural land rent. This methodology is applicable as actuarial form for calculation the above mentioned price as indicated value of agricultural land or its ‘epicentral point’ for transactions and agricultural land management. For understandable ownership reasons this concept as ‘obligatory’ one can only be applied on land owned by the Republic of Croatia. In the same way agricultural land and family farm transactions should not be within a lower price range than their methodologically calculated price within the system of pre-emption right that the Republic of Croatia has. The method of capitalisation of absolute agricultural rent was used in this research paper and data from the Regulation on the method of revaluation of rent (NN 65/2019 - 5.7.2019.) was used as a basis for revaluating the present calculation of fair prices. We were especially interested in comparing prices in different counties in the Republic of Croatia with those in five counties that constitute Slavonia and Baranja. This calculation did not evaluate physical and chemical elements of assessing the soil quality of agricultural land which would require additional elements from FAO methodology. Even though this does not appear to be a market-based approach, it is acceptable since the nature of agricultural land is such that its value cannot be calculated using the classical ‘formula’ for market-based mechanisms. Moreover, the paper presents comparison of prices of agricultural land and trends regarding the prices between the EU members and the Republic of Croatia for the period from 2013 to 2020

UTJECAJ NAČINA SUŠENJA NA EKSTRAKCIJU ULJA IZ SJEMENKI GROŽĐA PRIMJENOM SUPERKRITIČNOGA CO2

Aim of this study was to monitor the influence of drying method (naturally and chamber drying) and different sample preparation on supercritical CO2 extraction of oil from three grape seed varieties (Graševina, Zweigelt, Cabernet Sauvignon). The highest oil content was obtained from naturally dried screened and washed seeds of red variety Cabernet Sauvignon (14.85%) and lowest from chamber dried screened seeds of white variety Graševina (7.67%). Peroxide value ranged from 0.36 to 1.77 mmol O2/kg oil, free fatty acids 0.28-8.0%, and insoluble impurities 0.05-0.28%. Determined fatty acids were palmitic (6.98-11.58%), stearic (3.82-6.59%), oleic (14.90-19.97%) and linoleic acid (61.82-71.96%) in oil obtained from naturally dried seeds and 6.84-8.68%, 4.12-5.73%, 15.10-20.18% and 67.88-70.76% in oil from chamber dried seeds, respectively. In defatted cakes after supercritical CO2 extraction, protein and fibre content ranged from 8.17 to 9.85% and 34.58 to 43.96%, respectively. According to ANOVA results, sample preparation and drying method had statistically significant influence on grape seed oil extraction.Cilj istraživanja bio je odrediti utjecaj načina sušenja (prirodno i u komornome sušioniku), kao i same pripreme sjemenki grožđa, na ekstrakciju ulja superkritičnim CO2 iz triju sorata grožđa (graševina, Zweigelt, Cabernet Sauvignon). Najveći udio ulja ekstrahiran je iz prirodno osušenih i prethodno opranih sjemenki grožđa crne sorte Cabernet Sauvignon (14,85%), dok je najmanje ulja dobiveno iz sjemenki osušenih u komornome sušioniku bijele sorte graševina (7,67%). Vrijednost peroksidnoga broja dobivenih ulja bila je u rasponu 0,36-1,77 mmol O2/kg, slobodne masne kiseline 0,28-8,0%, a netopljive nečistoće 0,05-0,28%. U ulju dobivenome iz prirodno osušenih sjemenki grožđa određene su sljedeće masne kiseline: palmitinska (6,98-11,58%), stearinska (3,82-6,59%), oleinska (14,90-19,97%) i linolna kiselina (61,82-71,96%). U ulju sjemenki grožđa prethodno osušenih u komori određene su sljedeće masne kiseline: palmitinska (6,84-8,68%), stearinska (4,12-5,73%), oleinska (15,10-20,18%) i linolna kiselina (67,88-70,76%). Nakon ekstrakcije superkritičnim CO2 u odmašćenim pogačama određen je udio proteina (8,17-9,85%) i vlakana (34,58-43,96%). Priprema uzorka i način sušenja sjemenki grožđa te sorta imaju značajan utjecaj na ekstrakciju i kvalitetu dobivenoga ulja

Distillation columns for bioethanol production

U radu će biti opisana proizvodnja bioetanola pomoću destilacijske kolone koju je konstruirao gospodin Ivan Jakobović (Patent broj: P20080037A). Etanol kao biogorivo je jedan od energenata koji će znatno pomoći pri rješavanju mnogih kompleksnih problema proizvodnje i potrošnje energije. U radu ćemo se bazirati na primjenu i proizvodnju etanola kao goriva. Jedan od bitnih razloga proizvodnje biogoriva svakako je smanjenje korištenja naftnih derivata, što bi uvelike doprinijelo u zaštiti okoliša. Industrija proizvodnje biogoriva je ekološki prihvatljivija. U vodi se, primjerice, potpuno razgrađuje za svega 28 dana, za što nafti treba punih 40 godina.The paper will describe the production of bioethanol using distillation column constructed by Mr. Ivan Jakobović (Patent No.: P20080037A). Ethanol as a fuel can significantly help in solving many complex problems of production and consumption of energy. We will be based on the use and production of ethanol as fuel. One important reason was the production of fuel is certainly reduce use of petroleum products, which would greatly contribute to environmental protection. Industry production of bio fuels is environmentally acceptable. In water, for example, breaks down completely in only 28 days for the oil to a full 40 years