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  • Author or Editor: E. Kovács x
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M. Knee (Ed.): Fruit quality and its biological basis; Sheffield Academic Press Ltd., Sheffield, UK, 2002, ISBN 1-84127-230-2, 279 pages; CRC, Boca Raton, Fl., USA, ISBN-0-8493-9781-2; L.M.M. Tijskens, M.L.A.T.M. Hertog and B.M. Nicolai (Eds): Food process modelling; CRC Press Boca Raton Boston, New York, Washington, DC; Woodhead Publishing Ltd., Cambridge, England, 2001, ISBN 1-85573-533-4, 496 pages;  K.V. Peter (Ed.): Handbook of herbs and spices; CRC Press, Boca Raton, USA, ISBN 0-8493-1217-5; Woodhead Publishing Ltd, Cambridge, England, 2001, ISBN 1-85573-5628, 319 pages

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Growth characteristics, such as basal stem diameter, total length of wooded branches and root/shoot ratios in different ecological populations of Fumana procumbenswere studied in the perennial open sand grassland Festucetum vaginataeunder different climatic conditions in Hungary. The age of individual plants was determined by counting the annual rings in the basal section of stems. Basal stem diameters and their average yearly increment as well as the total length of wooded branches with individuals of the same age were significantly higher under wet conditions. The close relation of basal stem diameters and branch length with age could be described by linear regression both under wet and dry conditions. There was no significant differences in the root/shoot ratios between the dry and wet sites. Having established a reliable relation between basal stem diameter and age of Fumanaindividuals, authors developed a simple, quick and non-destructive field method for age determination of Fumana.

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Authors: Zs. Cserhalmi and E. Kovács
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Apples were harvested at three different times (1 st, 2 nd and 3 rd) then stored at 1-3 °C, 85-90% R.H. for 5 months. Firmness, ethylene productivity, the distribution of calcium and potassium and the ion leakage were measured. The ultrastructure of the cell wall was studied by SEM and TEM and he activity of β-galactosidase and polygalacturonase and pectin content were determined. The ethylene evolution of fruits decreased by the harvest and storage time. At the beginning of storage, the ethylene productivity in the 1 st harvest apple increased up to a maximum value then declined. The 2 nd harvest fruits produced less ethylene than that observed in 1 st harvest fruits. No ethylene production was found in the 3 rd harvest fruits. Firmness was different according to harvest time, but that difference disappeared during storage. The permeability of membranes increased as a function of harvests and storage. The distribution of calcium was typical at the beginning, the highest concentration of calcium being near the core and skin, but by the end of the storage calcium moved from the skin towards the core. Potassium content was the highest near the core and decreased towards the skin, both in the fresh and stored apples. The activities of polygalacturonase and β -galactosidase were not influenced by the harvest time, but changed as a function of storage time. The autolysis of pectin and soluble carbohydrates increased during storage, mostly in the 3 rd harvest. At the beginning of storage, the cell wall and middle lamellae of the 1 st harvest fruits' flesh were not damaged. Large degradation of the middle lamellae was observed in the 2 nd and 3 rd harvest fruits. Lower membrane permeability, pectin degradation and PG enzyme activity were found in the 1 st harvest apples. The Idared apple should be harvested close to the climacteric maximum for better and longer storage.

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Authors: K. Kovács and E. Csáki
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Abstract

In this paper a complex drive chain is modelled with Local Linear Neuro-Fuzzy Model (LLNF). The developed models were used for detecting different faults that may occur in the system. The models were developed based on measurements carried out on the real system. Using feed-forward neural networks with perceptron neuron structure, model-based fault diagnosis of the analysed system was developed to separate the different faults. The performance and efficiency of the developed different types of artificial neural network's structures were compared using gradient based edge detection method.

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The effect of organic growing was studied on the storability of apple cv. Jonica, Liberty, Mutsuand Pinova. Fruits from integrated and organic orchards were stored at 2-4 °C, 95-99% relative humidity for 6 months. Firmness, activity of b-galactosidase and polygalacturonase enzymes were examined. There was no difference in the activity of β-galactosidase and polygalacturonase enzymes at harvest between the organic and integrated apples, but a significant difference was noted between the cultivars except for Mutsu and Pinova. The activity of b-galactosidase enzyme increased significantly during storage except for cv. Pinova and that of polygalacturonase enzyme also increased significantly. The difference in the activity of polygalacturonase became significant between the cultivars during storage except for cv. Jonica and Pinova. The firmness decreased significantly during storage, with the least change in case of cv. Liberty. It can be established that there is, in general, neither a considerable difference between the growing systems nor between varieties at harvest. The differences became higher during storage. It can be stated that the effect of cultivar on the storability is much more considerable than the effect of growing system.

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The crystallization of Al-Ce alloys was studied by DTA. The melting and freezing DTA curves of the investigated alloys exhibit two peaks, corresponding to the transformations of a high-purity phase and the eutectic phase, respectively. The peaks could be separated during both freezing and melting by changing the heating or cooling rate. The final temperature of the phase transformation is marked by the starting temperature of the second peak. A slight shoulder on the DTA peak, even on the opposite side to the maximum point, may correspond to the final temperature.

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Yellow pea flour contains very low quantity of prolamins, thus it could be a good alternative dietary source for individuals suffering from celiac disease or wheat allergy. Beside emulsifiers, enzymes can be used for developing noodle structure with high quality. Transglutaminase (TG) enzyme was tested in model systems for improving noodle structure by using beneficial cross-linking property of the enzyme. Sensory-and cooking properties and biochemical attributes of proteins were evaluated to characterize structure-function relationships in accordance with the concentration of the applied enzyme. The amount of water and salt soluble protein fractions was reduced meaningfully and the molecular weight distributions assessed by SDS PAGE were changed by addition of 50–200 mg kg −1 TG enzyme. At the same time, sensory properties were improved and high water uptake and low cooking loss were also observed. Forasmuch an increase has been expected in the amount of the cross-linked molecules, the cross-reactivity of prolamins with anti-gliadin antibody was also tested to reduce the risk related to gluten sensitivity. Finally, the possible contamination with wheat was controlled by DNA-based PCR.

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