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Acta Alimentaria
Authors: P. Penksza, R. sárosi, R. Juhász, K. Manninger-kóczán, B. Szabó-Nótin, L. Szakács, and J. Barta

Kip, P., Meyer, D. & Jellema, R.H. (2006): Inulins improve sensoric and textural properties of low-fat yoghurts. Int. Dairy J., 16, 1098–1103. Jellema R.H. Inulins improve

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Valeria Palermo, Ángel G. Sathicq, Patricia G. Vázquez, Horacio J. Thomas, and Gustavo P. Romanelli

adsorption technique. These catalysts were well characterized by means of 31 P-NMR, UV–visible spectra, FT-IR spectra, thermal analysis, and textural properties. Mo, V and Bi amounts were estimated by ICP-AES analysis. Experimental

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heating. Microwaved doughs’ exterior remains tough while the interior is hard and chewy [ 2 ]. These and other deleterious textural properties have been discussed elsewhere [ 3 – 7 ]. Par-baking the dough prior to reheating improves bread quality

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Abstract  

Pt/MCM, Pt/SiO2, Pd/MCM and Pd/SiO2 were prepared and characterized by H2-TPR, TEM, 29Si-CP-MAS-NMR, DRS-UV-Vis and tested in the hydrodechlorination of 1,2-dichloroethane. Differences in the catalytic behavior were related with textural properties.

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Abstract  

The effect of the iron precursor on the thermal decomposition of iron oxyhydroxides was studied by DSC, DTA and TG in this work. Samples were prepared from iron nitrate, iron sulfate and iron chloride and the thermal curves obtained were analyzed by specific area measurements, X-ray diffraction and Mssbauer spectroscopy. It was found that the iron oxyhydroxide precursors affect the temperatures of the hematite formation as well as the textural properties of the final hematite producing particles with different diameters as following: iron sulfate (3.3 nm)<iron nitrate (15 nm)<iron chloride (24 nm).

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Abstract  

This work is focused on the gas and liquid-phase adsorption of pollutants: propanol, 2-butanone, phenol and nicotine onto zeolites (H-BETA, H-ZSM-5, H-MCM-22, and clinoptilolite). Textural properties and origin of zeolites were taken into account as criteria of adsorbents selection. The aldehyde and the ketone were adsorbed in the gas phase using microcalorimetry linked to a volumetric line to evaluate adsorption. Adsorptions in water were carried out for phenol and nicotine and the evolved heats during adsorption were measured by a differential heat flow reaction calorimeter with stirring. Results are discussed in relation with the pore sizes and various interactions which could occur between the adsorbent and the adsorbate.

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Potato wedges were deep, shallow, and par-fried in soybean, sesame, and mustard oils using a laboratory formulated citric acid based antioxidant. The wedges were stored at –18 °C for 10, 20, 30, and 40 days. The quality of the wedges was assessed by subjective method (sensory analysis) and objective method (texture studies). Fuzzy logic was applied as a tool to analyze the linguistic data of subjective evaluation. Objective evaluation was conducted by studies on hardness, shear modulus and shear energy of the wedges. The wedges with highest defuzzified scores (obtained by sensory evaluation) and minimum changes in textural properties (P<0.05) were obtained in par-fried soybean oil (after 40 days storage) and in deep fried sesame and mustard oils (both after 30 days storage). The ranking of fried wedges (in the antioxidant administered oils) based on defuzzified scores after 40 days were: sesame > mustard > soybean (deep fry), mustard > soybean > sesame (shallow fry) and soybean > mustard > sesame (par-fry).

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Abstract  

Activity concentrations using gamma-ray spectrometer and distributions of natural radionuclides in soil samples collected were investigated to assess the environmental radioactivity and characterization of radiological hazard. The average concentrations of 238U, 232Th series and 40K in the 5 cm depth soil were 22.53, 33.43 and 406.62 Bq kg−1, respectively, which was within world median ranges in the UNSCEAR 2000 report. The average absorbed dose rate estimated by soil activity and annual effective doses were 49.32 nGy h−1 and 60.48 μSv, respectively. Since the soil is an important building material, the mean radium equivalent activity (Ra eq), external (H ex) and internal (H in) hazard index using various models given in the literature for the study area were evaluated as 101.72 Bq kg−1, 0.27 and 0.34, respectively, which were below the recommended limits. The effects of pH value, conductivity, true density and textural properties of soil samples on the natural radionuclide levels were also studied. The application of cluster analysis (CA) and principal component analysis (PCA), coupled with Pearson correlation coefficient analysis, were utilized to analyze the data, identify and clarify the effects of physico-chemical properties on natural radioactivity levels. The CA and PCA results showed that the former method yielded three distinctive groups of the soil variables whereas the latter one yielded the number of variables into three factors with 87.5% variance explanation.

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The influence of a food-grade long-chain polyphosphate mixture on the growth and survival of spoilage micro-organisms during storage in an experimental processed cheese spread formulation was evaluated. The emulsifying salt was added to the cheese blend at a concentration of 0.5% or 1.0%. A control product was also manufactured, which contained monophosphate instead of polyphosphate as emulsifying salt, with all other ingredients being identical to those in the experimental processed cheese spread. Half of the finished products were subjected to accelerated shelf-life testing at 37 °C for 10 days, whereas the other half of them was stored refrigerated at 4 °C for 120 days. Microbiological analyses (enumeration of viable cell counts, mesophilic sulphite-reducing clostridia, coliforms, yeasts and moulds) and sensory tests were performed at regular intervals. The results showed that polyphosphates had a beneficial effect on the shelf-life of the processed cheese spread tested in that they significantly reduced (P<0.05) the growth or survival rates of spoilage bacteria, especially of mesophilic sulphite-reducing clostridia. Polyphosphates also beneficially influenced the sensory, including textural properties of the experimental processed cheese spread. All the samples containing less than 1% polyphosphate showed signs of butyric blowing significantly earlier (P<0.05), during both accelerated shelf-life tests and regular refrigerated storage, than did the products fortified with 1% polyphosphate. In conclusion, the suitability of the long-chain polyphosphate formulation tested for shelf life extension of processed cheese spreads was demonstrated.

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Progress in Agricultural Engineering Sciences
Authors: István Dalmadi, Dávid Kántor, Kai Wolz, Katalin Polyák-Fehér, Klára Pásztor-Huszár, József Farkas, and András Fekete

High hydrostatic pressure (HHP) processing technology offers the possibility to preserve quality attributes. Objective test methods describing quality in a complex form have an important role in the development of new products and in the quality assurance of different technologies. Therefore, research was performed to compare the effects of HHP treatment and heat pasteurization on visual appearance, volatile composition, taste and texture properties of strawberry purees measured by sensorial and objective methods. Sensory evaluation did not show significant differences between samples. Similar result was obtained from the color measurements. Viscosity of purees changed only slightly as a result of the treatments. Electronic nose and electronic tongue were found to be promising tools for discrimination of strawberry purees treated by different levels of high hydrostatic pressure or thermal treatment. Canonical discriminant analysis showed that control and “600 MPa for 5 minutes” samples were quite similar. Samples treated by 600 MPa for 15 minutes were distinguished from the above mentioned ones. The heat treated samples (80°C for 5 and 15 minutes) were definitely separated from the control samples. Fusion of the data from the electronic nose and tongue showed the same trend and improved the classification of the treated puree samples.

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