16 research outputs found

    Physico-chemical Properties of Corn Extrudates Enriched with Tomato Powder and Ascorbic Acid

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    The aim of this research was to investigate the influence of the addition of tomato powder (TP) to corn grits at levels 4, 6 or 8 % and the addition of ascorbic acid (AA) at levels 0.5 and 1 %, on total polyphenol content (PF), and antioxidant activity of the extrudates. The hardness and the expansion ratio of the extruded products were also tested. Mathematical models that describe the influence of additives on the mentioned properties were also determined. Extrusion was performed at two temperature regimes: 135/170/170 Ā°C and 100/150/150 Ā°C. Lower temperature regime led to increased hardness and the expansion of extrudates. The addition of tomato and AA led to decreased hardness and the expansion at both temperature regimes. The addition of tomato increased PF and AA compared with pure corn extrudates. Greater degradation of PF and AA was at lower temperature regime. High correlation between PF and AA was demonstrated at both extrusion temperatures

    High-Voltage Electric Discharge Extraction of Bioactive Compounds from the Cocoa Bean Shell

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    This study is focused on the application of high-voltage electric discharge (HVED) to recover some bioactive compounds from the cocoa bean shell. Different extraction times (30, 60, 90 min), frequencies (40, 70, 100 Hz) and solvent-solid ratios (10, 30 and 50 mL gā€“1) were used to obtain cocoa bean shell extracts. Desired bioactive compounds, methylxanthines and phenolic compounds were measured in obtained extracts by high-pressure liquid chromatography with diode array detector. The obtained extracts showed that theobromine was the most abundant, ranging from 2530.13 to 6031.51 mg kgā€“1, while caffeine content was in the range from 316.08 to 849.88 mg kgā€“1. In addition, significant amounts of phenolic compounds were found, namely catechin (115.91 to 284.33 mg kgā€“1), epicatechin (20.20 to 358.90 mg kgā€“1), and gallic acid (80.28 to 219.17 mg kgā€“1). Results showed that different parameters of HVED extraction have statistically significant influence on cocoa bean shell composition, suggesting how this byproduct can be used in the production of valuable extracts. This work is licensed under a Creative Commons Attribution 4.0 International License

    Influence of buckwheat and chestnut flour addition on properties of corn extrudates

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    The aim of this study was to determine the effect of buckwheat and chestnut flour addition to corn meal (ratio meal : flour = 70 : 30, 50 : 50 and 30 : 70) on extrudate properties. Blends (25 % moisture) were extruded at two temperature regimes: 80/90 Ā°C and 75/180 Ā°C. Physical, chemical and rheological properties, and digestibility of the obtained extrudates were investigated in relation to non extruded samples. Addition of chestnut flour to corn meal resulted in increase of fibre, ash and fat content, and decrease of protein content, while buckwheat flour addition resulted in increase of all measured components. Chestnut and buckwheat flour addition increased whiteness and decreased yellowness of non-extruded samples. While extrusion of corn meal resulted in increase of whiteness, extrusion of both types of mixtures resulted in its decrease. Bulk density increased and expansion ratio, hardness and fracturability decreased by addition of chestnut and buckwheat flour. Extrusion of all investigated samples resulted in decrease of peak, hot and cold viscosity and increase of water absorption index. Total polyphenol content and antioxidant activity increased by the addition of buckwheat and chestnut flour, but the extrusion caused their decrease

    The effects of the fermentation with immobilized yeast and different cherry varieties on the quality of cherry brandy

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    The aim of this research was to investigate influence of different fermentation processes (by immobilized yeast cells and classical fermentation) and different cherry varieties (Maraska, Montmorencys and Kelleris) on the chemical and sensorial characteristics of cherry brandies. Cherry brandies were analyzed to determine chemical composition, aroma profile and sensory properties. Cherry brandies produced by immobilized yeast cells had a higher content of aldehydes, but lower content of total acids, total extract, higher alcohols and esters compared to the samples produced by classical fermentation process. Furfural was not detected in cherry distillates produced by immobilized yeast cells, while distillates produced by classical fermentation process had very low content. Cherry brandies produced by classical fermentation process had significantly higher content of benzaldehyde which has great influence on aroma of cherry brandies. Ethyl octanoate which is considered one of the most important contributors to the aroma of alcoholic distillates was found in the highest concentrations in Maraska distillates. The best evaluated sample was brandy produced from Maraska cherry variety fermented by immobilized yeast cells followed by brandy produced also from Maraska cherry variety, but by classical fermentation process

    Effect of screw configuration, moisture content and particle size of corn grits on properties of extrudates

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    Extrusion is a modern procedure for processing different types of raw materials and production of wide range of food products, where the corn grits are often used as main raw materials. Therefore the aim of this study was to determine the effect of screw configuration (4:1 and 1:1), moisture content (15% and 20%) and particle size of corn grits (>500 Āµm and <500 Āµm) on properties of extrudates. Samples were extruded in the laboratory single screw extruder Brabender 19/20 DN, at temperature profile 135/170/170 Ā°C, using die with 4 mm diameter. Physical and rheological properties, digestibility and starch damage of the obtained extrudates were determined, and results were compared with control samples of non-extruded corn grits. Lower moisture content and usage of screw with compression ratio 4:1 increased expansion ratio and fracturability, but decreased bulk density and hardness of extrudates, regardless of granularity. After extrusion process water absorption index increased, but peak, hot and cold viscosity of all samples decreased, with more pronounced effect in grits extruded with lower moisture content and with screw 4:1. Extrusion caused a reduction of the resistant starch content and increase starch damage of all samples

    Environmentally Friendly Packaging Materials Based on Thermoplastic Starch

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    Low-density polyethylene (LDPE) is extensively used as packaging material, and as such has a short service life, but long environmental persistence. The alternative to reducing the impact of LDPE as packaging material on the environment is to blend it with carbohydrate-based polymers, like starch. Therefore, the focus of this investigation was to prepare bio-based blends of LDPE and thermoplastic starch (TPS) containing different amounts of TPS using a Brabender kneading chamber. Due to incompatibility of LDPE/TPS blends, a styreneā€“ethylene/butyleneā€“styrene block copolymer, grafted with maleic anhydride (SEBS-g-MA) containing 2 mol % anhydride groups, was added as a compatibilizer. The effect of the biodegradable, hydrophilic TPS, its content, and the incorporation of the compatibilizer on the properties of LDPE/TPS blends were analysed. The characterization was performed by means of thermogravimetric analysis (TG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and water absorption (WA). Based on the results of the morphological structure, a good dispersion of the TPS phase in LDPE matrix was obtained with the incorporation of compatibilizer, which resulted in better thermal and barrier properties of these materials

    Towards a dynamic earthquake risk framework for Switzerland

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    Scientists from different disciplines at ETH Zurich are developing a dynamic, harmonised, and user-centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue generated by the Swiss Seismological ServiceĀ (SED) using the national seismic networks. This framework uses all available information to assess seismic risk at various stages and facilitates widespread dissemination and communication of the resulting information. Earthquake risk products and services include operational earthquakeĀ (loss) forecastingĀ (OE(L)F), earthquake early warningĀ (EEW), ShakeMaps, rapid impact assessmentĀ (RIA), structural health monitoringĀ (SHM), and recovery and rebuilding effortsĀ (RRE). Standardisation of products and workflows across various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access the same databases, workflows, and software is a crucial component. A user-centred approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a significant innovation featured in all products and services. Here we report on the key considerations and developments of the framework and its components. This paper may serve as a reference guide for other countries wishing to establish similar services for seismic risk reduction.</p

    Influence of buckwheat and chestnut flour addition on properties of corn extrudates

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    The aim of this study was to determine the effect of buckwheat and chestnut flour addition to corn meal (ratio meal : flour = 70 : 30, 50 : 50 and 30 : 70) on extrudate properties. Blends (25 % moisture) were extruded at two temperature regimes: 80/90 Ā°C and 75/180 Ā°C. Physical, chemical and rheological properties, and digestibility of the obtained extrudates were investigated in relation to non extruded samples. Addition of chestnut flour to corn meal resulted in increase of fibre, ash and fat content, and decrease of protein content, while buckwheat flour addition resulted in increase of all measured components. Chestnut and buckwheat flour addition increased whiteness and decreased yellowness of non-extruded samples. While extrusion of corn meal resulted in increase of whiteness, extrusion of both types of mixtures resulted in its decrease. Bulk density increased and expansion ratio, hardness and fracturability decreased by addition of chestnut and buckwheat flour. Extrusion of all investigated samples resulted in decrease of peak, hot and cold viscosity and increase of water absorption index. Total polyphenol content and antioxidant activity increased by the addition of buckwheat and chestnut flour, but the extrusion caused their decrease

    Influence of buckwheat and chestnut flour addition on properties of corn extrudates

    No full text
    The aim of this study was to determine the effect of buckwheat and chestnut flour addition to corn meal (ratio meal : flour = 70 : 30, 50 : 50 and 30 : 70) on extrudate properties. Blends (25 % moisture) were extruded at two temperature regimes: 80/90 Ā°C and 75/180 Ā°C. Physical, chemical and rheological properties, and digestibility of the obtained extrudates were investigated in relation to non extruded samples. Addition of chestnut flour to corn meal resulted in increase of fibre, ash and fat content, and decrease of protein content, while buckwheat flour addition resulted in increase of all measured components. Chestnut and buckwheat flour addition increased whiteness and decreased yellowness of non-extruded samples. While extrusion of corn meal resulted in increase of whiteness, extrusion of both types of mixtures resulted in its decrease. Bulk density increased and expansion ratio, hardness and fracturability decreased by addition of chestnut and buckwheat flour. Extrusion of all investigated samples resulted in decrease of peak, hot and cold viscosity and increase of water absorption index. Total polyphenol content and antioxidant activity increased by the addition of buckwheat and chestnut flour, but the extrusion caused their decrease

    Which Picker Fits My Data? A Quantitative Evaluation of Deep Learning Based Seismic Pickers

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    Seismic event detection and phase picking are the base of many seismological workflows. In recent years, several publications demonstrated that deep learning approaches significantly outperform classical approaches, achieving human-like performance under certain circumstances. However, as studies differ in the datasets and evaluation tasks, it is unclear how the different approaches compare to each other. Furthermore, there are no systematic studies about model performance in cross-domain scenarios, that is, when applied to data with different characteristics. Here, we address these questions by conducting a large-scale benchmark. We compare six previously published deep learning models on eight data sets covering local to teleseismic distances and on three tasks: event detection, phase identification and onset time picking. Furthermore, we compare the results to a classical Baer-Kradolfer picker. Overall, we observe the best performance for EQTransformer, GPD and PhaseNet, with a small advantage for EQTransformer on teleseismic data. Furthermore, we conduct a cross-domain study, analyzing model performance on data sets they were not trained on. We show that trained models can be transferred between regions with only mild performance degradation, but models trained on regional data do not transfer well to teleseismic data. As deep learning for detection and picking is a rapidly evolving field, we ensured extensibility of our benchmark by building our code on standardized frameworks and making it openly accessible. This allows model developers to easily evaluate new models or performance on new data sets. Furthermore, we make all trained models available through the SeisBench framework, giving end-users an easy way to apply these models
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