Changes in chemical composition and sensory properties caused by chemical and microbiological methods of deacidification in Moslavac (syn. Furmint) wines were investigated. Alcoholic fermentation of ...Moslavac musts was carried out with two different strains of the yeasts Saccharomyces paradoxus. There were no marked differences in chemical composition among the wines. Compared to the control microbiological deacidification of wines by Oenococcus oeni resulted in a complete decomposition of malic acid, total acidity decrease of 1.55 g/L and pH value increase of 0.14 units. There were no significant differences in volatile acidity, tartaric and citric acid concentrations between the control and malolactically fermented wine. Chemically deacidified wines contained similar total acidity but higher pH values than malolactically fermented wines. Compared to control wines, the tartaric acid concentration decrease of 2.13 g/L and the pH value increase of 0.5 units were determined. The sensory quality of Moslavac wines of high acidity was improved by the applification of deacidification methods. Chemically deacidified wines were assessed as the best whereas the quality of the control wines was judged inferior.
The composition and sensory properties in Riesling wines of suppressed, natural and induced malolactic fermentation (MLF) were investigated. A Riesling wine from the vintage 1998 was produced by the ...usual technology for white wines. After completion of alcoholic fermentation, wine was racked and divided into 35 L glass bottles for different treatments. The first treatment was suppressed MLF with SO2 and storage at 10°C. The second one included natural MLF and the third MLF was induced with starter culture Oenococcus oeni. After the MLF of the wines was completed, the wines were analysed and sensory tested. The analysis of the organic acids were performed by HPLC and the concentrations of volatile compounds were determined by gas chromatography.
Malic acid decomposition was completed in wines of all MLF treatments and the result was a significant decrease of total acidity up to 1.3 g/L and an increase of the pH value of 0.1 units. No differences in the concentrations of volatile acidity and ethyl acetate were detected between the wines of suppressed, natural and induced MLF.
MLF was not accompanied by tartaric acid degradation. The citric acid concentration was reduced by up to 42 %. The concentrations of 1-propanol, isobutanol, isoamyl alcohol and 2-phenylethanol remained unchanged after malolactic fermentation. The concentrations of isoamyl acetate, isobutyl acetate, ethyl butyrate and ethyl caproate were lower in the MLF wines. These wines contained more ethyl lactate and diethyl succinate. Higher quantities of ethyl caprylate, ethyl caprate, caproic, caprylic and capric acids were determined in the MLF wines.
Wines of suppressed MLF were of inferior quality compared with malolactic fermented wines, while wines of natural MLF were significantly better.
Vina Traminca proizvedena uobičajenom tehnologijom za bijela vina te maceracijom od 3 sata sa i bez dodatka enzima analizirana su kako bi se utvrdile razlike u kemijskom sastavu i senzornim ...svojstvima. Kemijska analiza i senzorno ocjenjivanje provedeni su odmah nakon fermentacije te nakon 12 mjeseci starenja vina u boci. Analiza viših alkohola i estera rađena je plinskom kromatografijom, a vina su senzorno ocijenjena paired sample testom i metodom redoslijeda. Vina dobivena maceracijom grožđa uz dodatak pektolitičkog enzima sadržavala su najviše koncentracije etil acetata, acetata viših alkohola i etil estera masnih kiselina te najniže koncentracije ukupnih viših alkohola. Izuzetak u tim vinima bio je sadržaj 1-propanola. Razlike u koncentracijama etil laktata i dietil sukcinata između vina svih tretmana nisu postojale. Nakon starenja vina u boci nisu utvrđene promjene u koncentracijama viših alkohola, dok je zabilježen pad koncentracija acetata viših alkohola i etil estera masnih kiselina a povišenje koncentracija etil laktata i dietil sukcinata. Najbolje ocijenjena bila su vina dobivena maceracijom uz dodatak pektolitičkog enzima, dok su vina proizvedena bez maceracije bila slabije kvalitete.
Changes in chemical composition and sensory properties caused by chemical and microbiological methods of deacidification in Moslavac (syn. Furmint) wines were investigated. Alcoholic fermentation of ...Moslavac musts was carried out with two different strains of the yeasts Saccharomyces paradoxus. There were no marked differences in chemical composition among the wines. Compared to the control microbiological deacidification of wines by Oenococcus oeni resulted in a complete decomposition of malic acid, total acidity decrease of 1.55 g/L and pH value increase of 0.14 units. There were no significant differences in volatile acidity, tartaric and citric acid concentrations between the control and malolactically fermented wine. Chemically deacidified wines contained similar total acidity but higher pH values than malolactically fermented wines. Compared to control wines, the tartaric acid concentration decrease of 2.13 g/L and the pH value increase of 0.5 units were determined. The sensory quality of Moslavac wines of high acidity was improved by the applification of deacidification methods. Chemically deacidified wines were assessed as the best whereas the quality of the control wines was judged inferior.
Cilj je ovog istraživanja utvrditi specifične enološke značajke vrste Saccharomyces paradoxus, potencijalne različitosti između vrste Saccharomyces paradoxus i Saccharomyces cerevisiae u sintezi ...hlapljivih komponenti te njihov utjecaj na kakvoću vina. Analizirane su koncentracije viših alkohola, masnih kiselina i hlapljivih estera, a vina su i senzorno ocijenjena. Rezultati su pokazali bitan utjecaj soja Saccharomyces paradoxus RO88 na kemijski sastav i senzorna svojstva vina Traminac te su upozorili i na razlike izme|u vrsta Saccharomyces paradoxus i Saccharomyces cerevisiae.
Addressing the growing need for environmentally friendly fungicides in agriculture, this study explored the potential of biopolymer microparticles loaded with metal ions as a novel approach to combat ...fungal pathogens. Novel alginate microspheres and chitosan/alginate microcapsules loaded with zinc or with zinc and silver ions were prepared and characterized (microparticle size, morphology, topography, encapsulation efficiency, loading capacity, and swelling behavior). Investigation of molecular interactions in microparticles using FTIR-ATR spectroscopy exhibited complex interactions between all constituents. Fitting to the simple Korsmeyer–Peppas empirical model revealed the rate-controlling mechanism of metal ions release from microparticles is Fickian diffusion. Lower values of the release constant k imply a slower release rate of Zn2+ or Ag+ ions from microcapsules compared to that of microspheres. The antimicrobial potential of the new formulations against the fungus Botrytis cinerea was evaluated. When subjected to tests against the fungus, microspheres exhibited superior antifungal activity especially those loaded with both zinc and silver ions, reducing fungal growth up to 98.9% and altering the hyphal structures. Due to the slower release of metal ions, the microcapsule formulations seem suitable for plant protection throughout the growing season. The results showed the potential of these novel microparticles as powerful fungicides in agriculture.
Dorada i skladištenje lana Matin, Ana; Brandić, Ivan; Majdak, Tugomir ...
Glasnik Zaštite Bilja
47., Številka:
3.
Paper, Journal Article
Recenzirano
Odprti dostop
Lan je jedna od najstarijih biljaka i već se tisućljećima uzgaja prije svega zbog sjemenki i vlakana. U posljednje vrijeme lan sve više koristi kao prirodni kompozit u izgradnji raznih materijala kao ...što su dijelovi automobila i slično. Dorada omogućuje uz modernu tehnologiju da vlakna lana postanu čvršća i dugovječnija te se time približava umjetno stvorenim materijalima, kao konkurent u tekstilnoj i građevinskoj industriji. Procesi dorade i skladištenja uvelike pridonose zastupljenosti lana na tržištu i popularnosti. Samom doradom utječemo i na kvalitetu sjemenki i ulja, kako u medicinske svrhe, tako i u prehrambenoj industriji. Razvojem tehnologije skladištenja lan prestaje biti kultura čija prerada završava kratko nakon žetve, već je poboljšanjem uvjeta skladištenja omogućena njegova dorada tokom čitave sezone sa minimalnom promjenom kvalitete vlakana i sjemena za daljnju doradu.
Since the initial moisture content in sunflower seeds after the harvest is rather high, seeds must be processed by convection drying so that their quality can be maintained for as long as possible a ...period of time. Sunflower is an oilseed crop, which can be used both as food and as a feedstock for energy production. The aim of this paper is to determine the influence of the convection drying process (at 60 °C, 80 °C and 100 °C) on energy characteristics of seeds of four sunflower hybrids (Apolon, NK Brio, PR 63 A 90 and PR 63 D 82), which by their characteristics belong to early and medium-early hybrids. It will also be determined if the energy used in the drying process can be recovered through utilisation of energy from husk. On the basis of the obtained results, the changes in energy characteristics were identified, namely, the content of non-combustible matters (water, ash, coke, fixed carbon and nitrogen) and of combustible matters (carbon, sulphur, hydrogen, oxygen, volatile matter), as well as higher and lower heating values of sunflower seeds. The resulting data prove that convection drying of sunflower husk has a positive influence on its energy characteristics.
Addressing the growing need for environmentally friendly fungicides in agriculture, this study explored the potential of biopolymer microparticles loaded with metal ions as a novel approach to combat ...fungal pathogens. Novel alginate microspheres and chitosan/alginate microcapsules loaded with zinc or with zinc and silver ions were prepared and characterized (microparticle size, morphology, topography, encapsulation efficiency, loading capacity, and swelling behavior). Investigation of molecular interactions in microparticles using FTIR-ATR spectroscopy exhibited complex interactions between all constituents. Fitting to the simple Korsmeyer–Peppas empirical model revealed the rate-controlling mechanism of metal ions release from microparticles is Fickian diffusion. Lower values of the release constant k imply a slower release rate of Znsup.2+ or Agsup.+ ions from microcapsules compared to that of microspheres. The antimicrobial potential of the new formulations against the fungus Botrytis cinerea was evaluated. When subjected to tests against the fungus, microspheres exhibited superior antifungal activity especially those loaded with both zinc and silver ions, reducing fungal growth up to 98.9% and altering the hyphal structures. Due to the slower release of metal ions, the microcapsule formulations seem suitable for plant protection throughout the growing season. The results showed the potential of these novel microparticles as powerful fungicides in agriculture.
Rapeseed is one of the most important oil plants in the world. The objective of this research was to analyse the influence of thermal treatment temperature on rapeseed quality, i.e. to investigate ...the content of oil and free fatty acids in chosen rapeseed hybrids: Turan, Traviata, NK Toccata, NK Petrol, PR 46 W 14 and PR 46 W 15. By their characteristics, these varieties are early, medium-early and medium-late hybrids. The initial moisture content of the investigated hybrids ranged from 11.28% to 11.69%. The hybrids were subjected to thermal process of thin-layer convective drying, at temperatures of 40°, 60° and 80°C and air velocity of 1.0 m/s. During the investigation, decomposition of oil due to drying at 80°C and increase of free fatty acids concentration above permitted 2% were observed. Furthermore, based on the obtained results, velocity of water release from seed have been determined, and the drying process was mathematically modelled, whereby determination coefficient (R2) and activation energy were also determined.
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