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Acta Biologica Hungarica
Authors:
Edit Horváth
,
Krisztina Bela
,
Csaba Papdi
,
Ágnes Gallé
,
László Szabados
,
Irma Tari
, and
Jolán Csiszár

Arabidopsis thaliana contains 54 soluble glutathione transferases (GSTs, EC 2.5.1.18), which are thought to play major roles in oxidative stress responses, but little is known about the function of individual isoenzymes. The role of AtGST phi 9 (GSTF9) in the salt- and salicylic acid response was investigated using 2-week-old Atgstf9 and wild type (Wt) plants. Atgstf9 mutants accumulated more ascorbic acid (AsA) and glutathione (GSH) and had decreased glutathione peroxidase (GPOX) activity under control conditions. Treatment of 2-week-old seedlings with 10−7 M salicylic acid (SA) for 48 h resulted in elevated H2O2 level and enhanced GST activity in Atgstf9 plants, 10−5 M SA treatment enhanced the malondialdehyde and dehydroascorbate contents compared to Wt. 50 and 150 mM NaCl increased the GST activity, AsA and GSH accumulation in Atgstf9 seedlings more pronounced than in Wt plants. We found that the Atgstf9 mutants had altered redox homeostasis under control and stress conditions, in which elevated AsA and GSH levels and modified GST and GPOX activities may play significant role. The half-cell potential values calculated from the concentration of GSH and GSSG indicate that this GST isoenzyme has an important role in the salt stress response.

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Abstract

Minimal processing technologies, like High Hydrostatic Pressure (HHP), heat treatments at low temperatures have an increasing role in food industry. Eggs are considered as functional foods, but for high retention of biological active compounds adequate minimal processing technologies are needed during preservation procedure. In our study, liquid egg yolk (LEY) was examined to meet consumer's expectations.

Combinations of pasteurization (57–63 °C, 5–7 min) and HHP (350–400 MPa, 5 min) were used to provide microbiological stability of LEY. After these treatments samples were examined for mesophyll aerobes and Enterobacteriaceae cell counts (using Nutrient agar an incubation of 30 °C, 48 h) and viscosity attributes (Anton Paar MCR 92).

Our results show that microbiological stability is significantly influenced by the different parameters of heat treatments and HHP. Heat treatment effected at least 3 orders of magnitude decrease in cell count. Viscosity attributes point out that higher pressure of HHP have a stronger effect on viscosity than the temperature of pasteurization.

The results point out a great opportunity for industrial use of minimal processing technologies for LEY. Microbiological safety is strongly influenced by the order of treatments, but viscosity may be independent from the order of the treatments.

Open access
Növénytermelés
Authors:
Tamás Spitkó
,
Dr. László Sági
,
Dr. János Pintér
,
Dr. L. Csaba Marton
, and
Dr. Beáta Barnabás

Összefoglalás

Három évben, két termőhelyes kísérletekben vizsgáltuk in vitro dihaploid (DH) vonal eredetű hibridkukoricák termőhelyi és évjárat reakcióit. A vizsgált növényi anyagban összesen tizennégy hibridkombináció termés és betakarításkori szemnedvesség eredményét hasonlítottuk össze két standard hibridkukorica teljesítményének átlagával. A kísérletünk célja annak kiderítése volt, hogy az általunk tesztelt DH vonalakkal alkotott kukoricahibridek hogyan reagálnak a különböző környezeti feltételek változására. Az eredmények értékelését követően megállapítottuk, hogy az eltérő évek és különböző termőhelyek hatására a vizsgált genotípusok különbözőképpen reagáltak. A kísérlet főátlaga alapján a hibridek többsége statisztikailag jelentősen a standard átlag alatt teljesített, voltak azonban olyan dihaploid vonalak, amelyek hibridben realizált teljesítménye a standard értékével megegyezett. A hibridek martonvásári kísérletben kapott eredményei alapján lehetőségünk nyílt a szülővonalak általános kombinálódó képességének (GCA) kiszámítására. A vizsgálatok során találtunk olyan kombinációt, amelynek agronómiai értéke és termőképessége nem maradt el a standard átlagtól. A DH vonalakat in vitro növényregenerációs rendszerben állítottuk elő, majd hosszú szelekciós nemesítést követően vizsgáltuk több termőhelyes teljesítmény-kísérletekben. Az in vivo dihaploid előállítás gyakorlatával szemben az ilyen eredetű DH vonalakból származó kukoricahibridek korábban még nem kerültek köztermesztésbe Magyarországon.

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Cereal Research Communications
Authors:
Szabolcs Lechoczki-Krsjak
,
Beáta Tóth
,
Csaba Kótai
,
Imre Martonosi
,
László Farády
,
László Kondrák
,
Ágnes Szabó-Hevér
, and
Ákos Mesterházy

Four nozzle types were tested on large scale trials with 2500 m 2 plot size. The AIC TeeJet, the TeeJet XR, the Turbo FloodJet and the Turbo TeeJet Duo nozzles were tested in 2006 and 2007. 250 l/ha spray amount was used for all nozzles at 7–8 km/hr speed. Nine fungicides generally used to control FHB were tested. Across nine fungicides the mean reduction in symptoms was 60 % for both AIC TeeJet and XR TeeJet nozzles, but the more effective fungicides performed better with the XR TeeJet nozzle. The Turbo TeeJet Duo nozzles reduced the symptoms by 70 % and the Turbo FloodJet nozzle by 80 %. Among the fungicides the Prosaro 1 l/ha was the most effective. The coverage was controlled by water sensitive paper stripes and UV sensitive color mixed into the spray. Data show better uniformity by paper stripes, the UV pictures show that the all-side protection by the Turbo FloodJet nozzle is not perfect, the coverage is less than anticipated. Therefore, further work is necessary for improve the coverage being necessary to an even more effective control. However, the existing improvements allow 80 % or higher reduction with the best fungicides giving a chance for a better protection. Small plot tests with the same fungicides gave highly similar results achieved with the large-scale farm application. Farm efficacy could be forecasted with r = 0.90 correlation based on small plot hand sprayed tests.

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Progress in Agricultural Engineering Sciences
Authors:
Emna Ayari
,
Csaba Németh
,
Karina Ilona Hidas
,
Adrienn Tóth
,
Dávid Láng
, and
László Friedrich

Abstract

Starting from mechanical revolution, each day new methods and new equipment have emerged. Today, the Ultra Heat Treatment (UHT) is one of the important technologies that permits to the industry to reduce processing time while maintaining the same quality of the products. Egg and egg products are known as heat-sensitive products, so the UHT enables us to preserve their qualities after a heat treatment.

Our aim is to study the effect of UHT treatment (approximately 67 °C for 190 s) on the Liquid Egg Yolk (LEY). For twenty-one days, the color and the apparent viscosity were measured every seven days, we also studied the damage of protein using DSC (Differential Scanning Calorimetry).

Comparing the two graphs of DSC, the denaturation of protein is distinct. The endothermic peak decreased. This could be seen also on the rheological curves. The apparent viscosity is diminished from 231 mPa.s on the 1st day of storage to 224 mPa.s on 21st day. However, the treated LEY could be stored for longer period than the raw LEY.

Open access
Acta Biologica Hungarica
Authors:
Parisa Rahimi Tamandegani
,
Doustmorad Zafari
,
Tamás Marik
,
András Szekeres
,
Csaba Vágvölgyi
, and
László Kredics

Five Iranian Trichoderma isolates from species T. viride, T. viridescens, T. asperellum, T. longibrachiatum and T. citrinoviride — selected from the Fungal Collection of the Bu Ali Sina University, Hamedan, Iran — were investigated for their peptaibol production. All examined isolates showed remarkable antibacterial activities during the screening of their extracts for peptaibol content with a Micrococcus luteus test culture. HPLC-ESI-IT MS was used for identification and elucidation of the amino acid sequences of peptaibols. The detected peptaibol compounds contain 20 or 18 amino acid residues and belong to the trichobrachin and trichotoxin groups of peptaibols, respectively. T. longibrachiatum and T. citrinoviride produced trichobrachins, while trichotoxins could be detected in T. viride, T. viridescens and T. asperellum. Out of 37 sequences detetermined, 26 proved to be new, yet undescribed compounds, while others were identified as previously reported trichotoxins (trichotoxin A-50s and T5D2) and trichobrachins (longibrachins AI, AII, AIII, BII and BIII). Compounds within the two groups of detected peptaibols differed from each other only by a single or just a few amino acid changes.

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Acta Biologica Hungarica
Authors:
Mónika Homa
,
Kinga Hegedűs
,
Ádám Fülöp
,
Vanessza Wolfárt
,
Shine Kadaikunnan
,
Jamal M. Khaled
,
Naiyf S. Alharbi
,
Csaba Vágvölgyi
, and
László Galgóczy

Despite the current therapeutic options, filamentous fungal infections are associated with high mortality rate especially in immunocompromised patients. In order to find a new potential therapeutic approach, the in vitro inhibitory effect of two antiarrhythmic agents, diltiazem and verapamil hydrochloride were tested against different clinical isolates of ascomycetous and mucoralean filamentous fungi. The in vitro combinations of these non-antifungal drugs with azole and polyene antifungal agents were also examined. Susceptibility tests were carried out using the broth microdilution method according to the instructions of the Clinical and Laboratory Standards Institute document M38-A2. Checkerboard microdilution assay was used to assess the interactions between antifungal and non-antifungal drugs. Compared to antifungal agents, diltiazem and verapamil hydrochloride exerted a relatively low antifungal activity with high minimal inhibitory concentration values (853–2731 μg/ml). Although in combination they could increase the antifungal activity of amphotericin B, itraconazole and voriconazole. Indifferent and synergistic interactions were registered in 33 and 17 cases, respectively. Antagonistic interactions were not revealed between the investigated compounds. However, the observed high MICs suggest that these agents could not be considered as alternative systemic antifungal agents.

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Progress in Agricultural Engineering Sciences
Authors:
Karina Ilona Hidas
,
Csaba Németh
,
Lien Phuong Le Nguyen
,
Anna Visy
,
Adrienn Tóth
,
László Friedrich
, and
Ildikó Csilla Nyulas-Zeke

Abstract

Freezing can enhance the storage time of liquid egg products, but egg yolk undergoes an irreversible textural and structural change when it is cooled to –6 °C. In this study, the effects of different salt concentrations on the physical properties of frozen-thawed egg yolk were investigated.

The pasteurised liquid egg yolk (LEY) was treated with 4, 5, and 6% of NaCl before freezing and it was stored at –18 °C for 4 weeks. The colour, pH, and rheological characteristics (firmness, consistency, cohesiveness, and index of viscosity) of yolk samples were evaluated before and after freezing.

Salt treatment resulted in preventing gelation, with decreasing firmness, consistency and viscosity compared to control samples. The pH of all yolk samples increased during frozen storage. The lightness value decreased in treated samples and increased in the control sample after freezing.

The results indicated that the applied salt concentrations could inhibit protein aggregation of LEY induced by freezing during the storage period. At least 5% salt concentration could reduce effectively the changes in rheological properties.

Open access
Progress in Agricultural Engineering Sciences
Authors:
Karina Ilona Hidas
,
Csaba Németh
,
Anna Visy
,
Adrienn Tóth
,
László Ferenc Friedrich
, and
Ildikó Csilla Nyulas-Zeke

Abstract

Eggs are commonly used in the food industry because of their excellent nutrient value and also for their coagulating, foaming, emulsifying, colouring and flavouring properties. Manufacturers substitute shell eggs with processed egg products, such as liquid whole egg, liquid egg yolk or albumin. They have a shelf life of a few weeks, but freezing can increase it to 1 year. However, freezing causes gelation in case of egg yolk. This process is highly dependent on the conditions of freezing and thawing.

In our study, raw liquid egg yolk was frozen and stored for 14 days at −18 °C. On days 1, 7 and 14 samples were thawed by two different methods. Denaturation temperature and enthalpy were investigated by differential scanning calorimetry. Besides, rheological properties were examined at 20 °C, Herschel–Bulkley model was fitted to flow curves of the examined samples. The dry matter content was also recorded during the experiment. Two-way ANOVA was used to analyse data.

The results of the study showed that method of thawing had no significant effect on calorimetric and rheological properties and dry matter content. In contrast, freezing and frozen storage had a significant effect on denaturation enthalpy and rheological properties.

Open access