Search Results

You are looking at 61 - 70 of 150 items for :

  • "Conversion" x
  • Biology and Life Sciences x
  • Refine by Access: All Content x
Clear All

, is lipid oxidation, which leads to the formation of rancid odour and flavour ( Domínguez et al., 2019 ). Meat discolouration is caused mainly by the conversion of oxymyoglobin to metmyoglobin ( Faustman et al., 2010 ). These two processes, causing

Open access

Wheat with its advantages of high yield stability, well-mastered crop management and the possibility of long-term storage is suitable for ethanol production. Ethanol production has to be cost-effective and, therefore, wheat used in production should have a high potential for ethanol production. Previous works showed that low-nitrogen grain content is important for the relative ethanol yield and the agronomic yield for the absolute ethanol yield per area is important. In this work, importance of grain nitrogen and starch content for ethanol conversion efficiency was verified. Furthermore, environmental effects in relation to the ethanol conversion efficiency and ethanol yield in conditions of Central Europe were studied. With regard to the environmental factors, the annual rainfall sum was found to be the most important factor for ethanol conversion efficiency, while the grain yield was found to be the most important factor for the ethanol yield. On the basis of these findings it can be considered that wheat varieties possessing high yields of low protein grain planted in areas with higher rainfall amount would be ideal for the production of ethanol.

Restricted access
Agrokémia és Talajtan
Authors: András Makó, Tamás Varga, Hilda Hernádi, Viktória Labancz, and Gyöngyi Barna

A lézerdiffrakciós szemcseanalízis egy korszerű módszer a talajmechanikai vizsgálatokban, ám egy egységes mérési szabvány bevezetése (akár műszerhez köthetően) nagymértékben növelné a mérések reprodukálhatóságát. A mérések tekintetében kiemelt szerepe van az előkészítő módszereknek (talajszerkezetet kialakító kötőanyagok roncsolása, elemi szemcsék diszpergálása), azonban ezen a téren is hiányzik az egységes szabványosítás. A tanulmányozott közlemények alapján megállapítható, hogy mind az optimális mintaelőkészítési módszer, mind pedig a legmegfelelőbb műszerbeállítás nagymértékben függ a mérni kívánt minta fizikai és kémiai sajátságaitól. A mérési eredmények hagyományos ülepítéses módszerrel kapott eredményekkel történő összehasonlítására szolgáló konverziós módszerek (frakció mérethatárváltások, illetve konverziós egyenletek) használhatósága is talajminta- és LDM vizsgálati módszer-függő. A lézeres szemcseanalízis alkalmazása a talajok aggregátum-stabilitás vizsgálata során ígéretes módszertani lehetőség, ám a mérések értelmezése és az összahasonlíthatóság megteremtése végett ezen a téren is elkerülhetetlen a szabványosítás.

Restricted access

Ethanol recovery from aqueous fermentation broth by extraction using oleic acid with simultaneous esterification by lipase enzyme was studied. To determine the optimal conditions for the complex process, the ternary system was characterised; binodal curves and tie lines of (ethanol+oleic acid+water) system were determined. Enzymatic esterification of ethanol and oleic acid was carried out and resulted in higher than 50% conversion with simultaneous reduction of ethanol content in the broth. Finally, the effect of the ester product (ethyl oleate) on the distribution of ethanol was determined.

Restricted access

” Ernte 2000 5 38 39 Padel S. 2001. Conversion to Organic Farming: A Typical Example of the

Restricted access
Cereal Research Communications
Authors: Judit Szabó-Fodor, László Kametler, Roland Pósa, Rene Mamet, Veronika Rajli, Johann Bauer, Péter Horn, Ferenc Kovács, and Melinda Kovács

The absorption, distribution and elimination of fumonisin B 1 (FB 1 ) and its metabolites was investigated in pigs. For the determination of the absorption and biotransformation of FB 1 , T-cannula were implanted into the distal part of experimental pigs’ ileum and the total urine and faeces moiety was collected during the toxin feeding (45 mg FB 1 /kg diet, duration: 10 days) and in the subsequent elimination period (10 days). At the end of trial several organs, muscle and fat samples were also collected. The accumulative absorption of fumonisin B 1 was 4%. In the chymus, the FB 1 conversion to aminopentol (totally hydrolysed FB 1 ; AP 1 ) and partially hydrolysed FB 1 (PHFB 1 ) was 1% and 3.9%, respectively. Derivatives of FB 1 were mostly accumulated in the liver and kidney, while in negligible concentration could be detected in the muscle and fat samples. In the organs the efficacy of the FB 1 to AP 1 and PHFB 1 conversion was 30% and 20%, respectively. In the faecal content the main hydrolised product was PHFB 1 (47%), with 12% of AP 1 . 1.5% of the FB 1 quantity taken up was excreted with the urine, about 35% in hydrolyzed form. Detectable amounts of FB 1 and its metabolites were measured in most of the organs, in faeces and urine even 10 days after the feeding of the noncontaminated diet. As a general conclusion, the intestinal microbiota of pigs is able to transform the intact FB 1 to a similarly toxic substance (partially hydrolyzed FB 1 ) or to a more toxic metabolite (aminopentol).

Restricted access

503 507 Christakopoulos, P., Makre, J. B., & Kekos, D. (1990): On the mechanism of direct conversion of cellulose to ethanol by Fusarium oxysporum : effect of cellulose and β

Restricted access

Because of the need for renewable energy resources, cellulose, which can be enzymatically hydrolyzed to glucose, has drawn lot of attention during the past decade. However, the process of cellulose conversion using cellulase is not yet economically feasible because of the high cost of enzymes. Factors influencing the cellulase production of Trichoderma koningii using both acid and steam treated sugar cane bagasse and rice straw as carbon sources were investigated. The highest levels of cellulase activities were obtained using a culture medium containing urea and (NH4)2SO4 together as nitrogen sources at 0.217% and 0.241% for both carbon sources. When the culture medium was supplemented either with 0.5% Tween 60 or Tween 80, the rate of cellulase production was increased considerably. Maximum levels of both filter paper and CMC-ase activities produced on both media were obtained at 25 °C and 100 r.p.m., while the highest level of â -glucosidase production was obtained at 30 °C and 200 r.p.m.

Restricted access

This work was conducted to study the changes in the content and composition of chlorophylls and carotenoids in ground thyme leaves as a function of supercritical carbon dioxide and sub-critical propane extraction. the results indicated that the maximum oleoresin yield could be obtained with supercritical carbon dioxide at 400 bar and 35 or 55 °C and sub-critical propane at 50 bar. Pigment solvating capacity of supercritical carbon dioxide increased with the increase of extraction pressure. Substantial variation was noticed in pigment composition between raw material, oleoresin and residues (powders after extraction). Chlorophyll b, chlorophyll a and the Mg-free derivatives were the dominant pigments in the raw material with other derivatives being minor constituents. After extraction with supercritical carbon dioxide at 35 °C and pressures higher than 200 bar, epimerisation and oxidation of chlorophylls lead to marked accumulation of artefacts in the residues. The content of oxidized chlorophylls was increased proportionally to the increase of the extraction pressure. The brownish green coloured-oleoresins contained only pheophytins indicating that rapid substitution of Mg with hydrogen atoms on the molecules takes place during extraction of such pigment by supercritical carbon dioxide and sub-critical propane. The marked conversion of chlorophyll to pheophytins was found in oleoresin extracted by supercritical fluid extraction at 55 °C and 100 bar.

Restricted access

A synthetic autopolyploid was developed from diploid Aegilops tauschii, D genome progenitor of common wheat (Triticum aestivum). The tetraploid Ae. tauschii displayed a markedly larger organ size than the diploid donor. Fluorescence in situ hybridization (FISH) and DNA marker analysis revealed that there is no clear variation at either the chromosomal or DNA level between the diploid and tetraploid plants. We analyzed the variation in cytosine methylation patterns between the diploid and tetraploid plants by methylation-sensitive amplified polymorphism (MSAP) and detected 228 and 232 methylated sites in diploid and tetraploid plants, respectively. Statistical comparison indicated that the tetraploid Ae. tauschii genotype displayed no significant difference in polymorphic methylation level compared to the diploid ones. Twenty-two different genomic fragments displaying different methylation behavior during the ploidy conversions were isolated and sequenced. It demonstrated that alterations in the level of methylation have the most profound effects on coding genes. We demonstrated that there are some genes expressions modified by DNA methylation may be correlated with phenotypic alteration after autotetraploidization.

Restricted access