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Avsaroglu, M. D., Buzrul, S., Alpas, H., Akcelik, M. (2007) Hypochlorite inactivation kinetics of lactococcal bacteriophages. LWT — Food Sci. Technol. 40 , 1369

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Cereal Research Communications
Authors: Maciej Buśko, Juliusz Perkowski, Marian Wiwart, Tomasz Góral, Elżbieta Suchowilska, Kinga Stuper, and Anna Matysiak

1576 Šrobárová, A., Buśko, M., Perkowski, J. 2007. Kinetics of DON, NIV and ERG formation in grain of two wheat cultivars after inoculation with three isolates of Fusarium culmorum (W

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. Although the drying kinetics of a product is a crucial parameter in this process, the experimental setup to measure the drying kinetics in an environment which comes close to the drying situation in a real spry dryer, is very difficult to establish. With

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Kinetics of ochratoxin A production was examined in a number of ochratoxin producing isolates representing different sections of the Aspergillus genus. Both weak and high ochratoxin producers were tested using immunochemical or high-performance liquid chromatograhic methods. All isolates were found to produce the highest amounts of ochratoxin A after 7-10 days of incubation. Ochratoxin production varied between 30 - 5×105 ng ml-1 among the Aspergillus isolates tested. The A. albertensis and A. melleus isolates examined were found to produce ochratoxin A constitutively. A. albertensis produced the highest amounts of ochratoxin A at 30 °C after 7 days' incubation in YES liquid medium. Ergosterol content and ochratoxin production of A. albertensis cultures were in good correlation.

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Hill, B. T., Whelan, R. D. H. (1982) A comparison of the lethal and Kinetics effects of doxorubicin and 4′-epidoxorubicin in vitro . Tumori 68 , 29–37. Whelan R. D. H. A

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The extractable (ASTA) colour retention of four different milled spice paprikas was evaluated at 10, 20, 35, 50, and 60 °C storage temperature. The ASTA colour stability during long-term storage period strongly depended on the temperature, primary handling and drying of the fresh crop, and the applied production technology. The cooled (10 °C) or temperature-controlled (20 °C) conditions appeared to be a reasonable solution to preserve the quality of paprika powder. The kinetics study on the temperature dependence of ASTA colour loss estimated the apparent reaction order, rate constants, predicted half-life times and activation energy. The Q10 approach and shelf life-plot resulted in useful data, which can be suitable for quick and economical evaluation of further spice paprika products.

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Apple cubes were osmotically dehydrated with 40 °Bx sucrose and sorbitol solutions. Light microscopy was used to observe the microstructure of fresh and osmotically dehydrated samples. Peleg’s model could fit the experimental data and describe the mass transfer kinetics of water loss (WL) and solid gain (SG). The use the sorbitol as osmotic agent, the increase of temperature and concentration of the solution increased the WL during the osmotic dehydration. The average cellular parameters, area and perimeter (size), and circularity, elongation, roundness, and compactness (shape) of fresh samples were 14.28±6.65×103 μm2 and 0.486 mm, and 0.73, 1.56, 0.70, 0.83, respectively. The osmotically dehydrated samples presented a decrease in area, circularity, roundness and compactness and an increase in the elongation of the cells, and these changes were higher in samples treated with sorbitol.

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-drying, freeze-drying) and extraction technology under different process parameters on anthocyanins content of red cabbage. As degradation of natural antioxidants occurs as function of different thermal treatments, thermal stability and degradation kinetics were

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Agrokémia és Talajtan
Authors: Bernadett Gyarmati, Zsuzsanna Hárshegyi, György Heltai, Csaba Mészáros, and Ágnes Bálint

A különböző N-formák mozgását és transzformációját a talaj–növény–légkör rendszerben egymással összefüggő ciklusok határozzák meg. Az olyan mesterséges beavatkozások, mint például a műtrágyák és szerves trágyák intenzív felhasználása, döntő mértékben befolyásolják a N-körforgalmat, jelentősen terhelve ezzel a ciklusok érzékeny egyensúlyát. Annak érdekében, hogy a problémákat kezelni tudjuk, a N-ciklus talajban lejátszódó folyamatainak jobb megértése, a különböző folyamatok súlyának és érzékenységének megismerése szükséges, alapot teremtve ezzel egy racionálisabb és környezetkímélőbb trágyázási és tápanyag-utánpótlási gyakorlatnak. A N-ciklus matematikai modellezése kiváló lehetőséget nyújt az egyes részfolyamatok alaposabb felderítésére. A munka során egy korábban elvégzett kísérlet adatait használtuk fel. Az inkubációs talajoszlop kísérletet a Szent István Egyetem Kémia és Biokémia Tanszékén végezték 2000-ben. A felhasznált kísérlet mérési adataira nemlineáris regresszióval illesztettünk különböző rendű kémiai kinetikai egyenleteket az Origin 4.1-es adatelemző és grafikai szoftverrel. A munka eredményeként megállapítható, hogy a részfolyamatok modellezésekor a legtöbb esetben az elsőrendű kémiai kinetikai egyenlet eredményezte a legjobb matematikai közelítést.

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Fibre-rich fruit juices are playing an increasing role in healthy nutrition, and consumers are regarding them, especially citrus juices of 100% fruit content, as reliable sources of vitamin C. Nevertheless relatively few scientific data are available on vitamin C retention during the heat treatment of aseptically packed fruit juices made from fruit concentrates. Authors investigated this problem within the scope of OTKA T 014965 research project (Körmendy et al., 1998, 1999a, 1999b; Pátkai, 1998).

Instead of separate case studies on different types of fruit juices and technologies, authors analysed the vitamin C content of model solutions with similar composition to real citrus juices as a function of temperature and duration of heat treatment and that of initial oxygen and ascorbic acid concentration. Based on the measured data, they elaborated kinetic relations and determined the reaction rate constants of vitamin C decomposition under the experimental conditions. By means of the calculated kinetic relations and reaction rate constants one can estimate the losses of vitamin C in the case of known parameters of the heat treatment, packaging material, oxygen and vitamin C concentration within the investigated domain. Results may promote technology and product development in the field of citrus fruit juices.

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