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1.
Int J Biol Macromol ; 278(Pt 2): 134618, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151851

RESUMO

Biomass-based slow-release fertilizers (SRFs) are a sustainable solution for addressing food scarcity, improving fertilizer efficiency, and reducing pollution, whereas they still face complex preparation, high costs, and low release characteristics. This study introduces a simple and innovative approach to producing bifunctional green SRFs with controlled release and conditioning properties for saline soils and harsh environments. The method involves a one-pot preparation of microsphere-structured amine-modified lignin slow-release fertilizer (L-UX) using biomass lignin as the starting material. The L-UX demonstrates an exceptional fertilizer loading rate (66.2 %) and extended slow-release performance (288 h), effectively enhancing the fertilizer's release ability. Compared to traditional fertilizers, the bifunctional L-UX significantly improves soil water retention capacity (824.3 %), plant growth, and germination percentage in challenging soil conditions (133 %). These findings highlight the potential of L-UX as a large-scale controlled-release fertilizer in harsh environments. A life cycle assessment (LCA) was also conducted to evaluate the environmental impact of L-UX from its production to disposal. This revealed that L-UX has a minimal environmental footprint compared to conventional inorganic fertilizers. This study further supports the widespread application of L-UX as an environmentally friendly alternative.


Assuntos
Aminas , Fertilizantes , Lignina , Solo , Lignina/química , Aminas/química , Solo/química , Preparações de Ação Retardada , Biomassa , Água/química
2.
Sci Rep ; 14(1): 16880, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39043793

RESUMO

Lightweight aggregates are a material used in many industries. A huge amount of this material is used in construction and architecture. For the most part, lightweight construction aggregates are obtained from natural resources such as clay raw materials that have the ability to swell at high temperatures. Resources of these clays are limited and not available everywhere. Therefore, opportunities are being sought to produce lightweight artificial aggregates that have interesting performance characteristics due to their properties. For example, special preparation techniques can reduce or increase the water absorption of such an aggregate depending on the needs and application. The production of artificial lightweight aggregate using various types of waste materials is environmentally friendly as it reduces the depletion of natural resources. Therefore, this article proposes a method of obtaining artificial lightweight aggregate consolidated using two methods: drum and dynamic granulation. Hardening was achieved using combined methods: sintering and hydration, trying to maintain the highest possible porosity. Waste materials were used, such as dust from construction rubble and residues from the processing of PET bottles, as well as clay from the Belchatów mine as a raw material accompanying the lignite overburden. High open porosity of the aggregates was achieved, above 30%, low apparent density of 1.23 g/cm3, low leachability of approximately 250 µS. The produced lightweight aggregates could ultimately be used in green roofs.

3.
Sci Rep ; 14(1): 10965, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745049

RESUMO

In areas where loess is distributed, landslides represent a significant geohazard with severe implications. Among these events, loess-mudstone landslides are particularly prevalent, posing substantial risks to the safety and property of local residents, and moisture plays a pivotal role as a key factor in causing these disasters. In this study, the hydraulic properties of the soils along the longitudinal section of an ongoing loess-mudstone landslide are investigated through the variation of soil water characteristic curves, which are subsequently fitted by utilizing van Genuchten model. Moreover, a comprehensive experimental investigation was conducted on the loess, mudstone, and loess-mudstone mixtures to facilitate analysis, including X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) observation, particle size distribution (PSD) analysis, along with fundamental geotechnical tests for parameter determination. It is found that mudstone and loess have distinct SWCC distribution. The SWCC of loess at various depths exhibits a similar distribution pattern due to the occurrence of landslide. The SWCC distribution of loess-mudstone mixture displays a transitional trend between the SWCC of mudstone and that of loess, and the water retention capacity increases as the mudstone content increases. The experimental findings have demonstrated notable agreement between each other and exhibited a satisfactory level of concurrence with the observed phenomena in geological surveys.

4.
J Environ Manage ; 355: 120430, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428182

RESUMO

The concept of rewilding, which focuses on managing ecosystem functions through self-regulation by restoring trophic interactions through introduced animal species with little human intervention, has gained increasing attention as a proactive and efficient approach to restoring ecosystems quickly and on a large scale. However, the science of rewilding has been criticized for being largely theory-based rather than evidence-based, with available data being geographically biased towards the Netherlands and Scandinavian countries, and a lack of objective data on rewilding effects on soil processes and C sequestration. In response to a call for data-driven experimental rewilding projects focused on national contexts, we collected unique data on the effects of large herbivore rewilding on soil properties from eight sites in the Czech Republic. These include sites with a wide range of edaphic characteristics that were grazed by Exmoor ponies, European bison, and back-bred Bos primigenius cattle (singly or in combination) for 2-6 years on areas ranging from ≈30 to ≈250 ha. Despite the relatively short duration of rewilding actions and considerable variability in the response rate of soil properties to grazing, our results indicate improved nutrient availability (evidenced by higher nitrification rate or higher soluble nitrogen concentration) and accelerated ecosystem metabolism (higher soil microbial biomass and dissolved carbon content). On longer-grazed pastures, rewilding contributed to soil carbon sequestration associated with increased water holding capacity and improved soil structure. However, other soil properties (reduced dissolved P concentration or total P content) showed signs of low P availability in the soils of the rewilding sites. Therefore, carcass retention should be considered where possible. Our data, although limited in number and geographic coverage, allow us to conclude that large ungulate rewilding has the potential to enhance soil carbon sequestration and related ecosystem services in rewilding areas. At the same time, we urge similar monitoring as an essential part of other rewilding projects, which will ultimately allow much more robust conclusions about the effects of this management on soils.


Assuntos
Ecossistema , Solo , Animais , Bovinos , Cavalos , Humanos , Solo/química , Carbono , Herbivoria , Biomassa , Espécies Introduzidas
5.
J Sci Food Agric ; 104(7): 3834-3841, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38394374

RESUMO

BACKGROUND: Starch is the main component of quinoa seeds. However, quinoa starch has poor solubility in cold water and poor mechanical resistance and is easily aged, which limit its application. Therefore, modification of its structure to improve its functional properties is necessary. RESULTS: This research used acetic anhydride and sodium trimetaphosphate to modify the structure of starch molecules and investigated their influence on bread quality. The results showed that both esterification and crosslinking prevented the aggregation behavior of starch molecules. Moreover, they both decreased the gelatinization enthalpy change and relative crystallinity of the starch. Compared with native starch, modification significantly decreased the gelatinization temperature from 57.01 to 52.01 °C and the esterified starch exhibited the lowest enthalpy change with a 44.2% decrease. Modified starch increased the specific volume and decreased the hardness and chewiness of bread. Modification did not influence the moisture content in bread but impacted the water retention capacity, depending on the degree of modification. Low and medium degrees of modification improved the water retention capacity during storage. By contrast, a high degree of modification (10 g kg-1 crosslinking agent) decreased the water retention capacity. The dually modified quinoa starch (esterified and crosslinked) showed no influence on the textural properties of bread. CONCLUSION: This study demonstrated that both esterification and crosslinking significantly improved the functional properties of quinoa starch. Crosslinked or esterified quinoa starches have the potential to improve the textural properties of bakery products. © 2024 Society of Chemical Industry.


Assuntos
Chenopodium quinoa , Chenopodium quinoa/química , Pão , Amido/química , Temperatura , Água/química
6.
Molecules ; 29(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38202852

RESUMO

Lemon peel represents an interesting by-product owing to its content of dietary fibre (DF) and (poly)phenols, which is of great importance for its valorisation. Hence, the objective of this study was to characterise the DF, total phenolic content (TPC), and antioxidant capacity of two lemon-peel-derived ingredients using two different methods (drying with warm air and enzymatic hydrolysis with pectinesterase). The analysis included a DF assessment, followed by neutral sugars characterisation through GC-FID and uronic acids determination via colorimetry. Subsequently, TPC and antioxidant capacity using the FRAP method were quantified through spectrophotometry. The swelling capacity (SWC), water retention capacity (WRC), and fat absorption capacity (FAC) were also determined as functional properties. It was observed that pectinesterase treatment led to a reduction in soluble DF and an increase in insoluble DF. This treatment also affected the pectin structure, thereby diminishing its ability to absorb water and fat within its matrix. The TPC was also reduced, resulting in a decrease in antioxidant capacity. Conversely, employing warm air exhibited a noteworthy increase in antioxidant capacity. This underscores its crucial contribution to the valorisation of lemon peel, not only by diminishing the environmental impact but also by enabling the acquisition of fibre ingredients with a noteworthy antioxidant capacity.


Assuntos
Antioxidantes , Fibras na Dieta , Antioxidantes/farmacologia , Cromatografia Gasosa , Colorimetria , Fenóis , Água
7.
Plants (Basel) ; 12(16)2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37631143

RESUMO

Bryophytes play a crucial role in the ecosystem's water compartment due to their unique ability to retain water. However, their role within temperate native ecosystems is mostly unknown. To address this knowledge gap, a study was conducted on Terceira Island (Azores), focusing on 14 bryophyte species found at different altitudes (40 m, 683 m, and 1012 m); five samples were collected monthly, per species and location, and their fresh, saturated, and dry weights were examined in the laboratory; four species were collected from more than one site. Generalized linear models (GLM) were used to assert the influence of climate factors (temperature, precipitation, and relative humidity) and environmental variables on two water indicators: field water content (FWC) and relative water content (RWC). None of the examined factors, per se, were able to explain all cases. Species appear to respond to climate according to a limiting factor effect: at lower elevations, precipitation was determinant, while at medium elevations, FWC was influenced by a combination of precipitation and relative humidity. At higher elevations, temperature was retained for seven of the nine studied species. The RWC values indicated that the 14 bryophyte species remained hydrated throughout the year but rarely reached their maximum water-holding capacity, even at the highest altitude. Understanding the mechanisms by which native bryophytes acquire, store, and release water is crucial for comprehending the resilience of native vegetation in the face of climate change. This knowledge can also enable the development of strategies to mitigate the effects of climate change and protect vital water resources.

8.
Meat Sci ; 204: 109256, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37336167

RESUMO

This research was carried out with the objective of evaluating the effects of using a chilling water sprinkler system during the cooling process of swine carcasses on the quantitative and qualitative parameters of carcass and meat. A total of 220 swine carcasses were divided in a completely randomized experiment and two treatments: (1) CONTROL, no water spraying; (2) SPRAY, with water spraying during cooling. Surface and internal temperature of carcasses throughout the cooling process, initial and final pH, and microbiological analyses of carcass surface were evaluated. Samples of the Longissimus lumborum (LL) were collected for analysis of color, cooking loss (CL), shear force (SF), and drip loss (DL). Data were submitted to analysis of variance through the SAS MIXED procedure adopting the most adequate model with treatments as fixed effects and pertinent random effects for each data set. The use of spray-chilling in the initial cooling process accelerates the surface and internal temperature decrease of swine carcasses, which may be a viable technological resource in swine industry.


Assuntos
Temperatura Baixa , Manipulação de Alimentos , Animais , Culinária , Manipulação de Alimentos/métodos , Carne/análise , Suínos , Temperatura
9.
Food Chem X ; 15: 100403, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36211758

RESUMO

Apple pomace, the by-product of the cider industry, contains a high content of antioxidant compounds and dietary fiber. Drying would allow its preservation for a later use. The aim of this study was to evaluate the effect of the drying temperature on the drying kinetics, antioxidant properties and the fiber characteristics. For this, drying experiments were performed at different temperatures (40-120 °C). The increase in temperature enhanced the drying rate, as was shown by the effective diffusivity and mass transfer coefficient identified by modelling. The influence of temperature was quantified through the activation energy (38.21 kJ/mol). Regarding the retention of antioxidant properties, the best results were found at 80-100 °C while 40-60 °C was the best temperature range for the fiber characteristics. Therefore, 80 °C could be an adequate temperature for drying of cider apple pomace, as it represents a good balance between kinetics, and antioxidant and fiber properties.

10.
Ying Yong Sheng Tai Xue Bao ; 33(8): 2113-2120, 2022 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-36043817

RESUMO

Current studies on water conservation capacity of litter in the mountainous area of Southwest China (MASC) mainly focus on local scale. Such results are difficult to evaluate the storage and water-holding capacity of litter in the whole MASC. In this study, the results of site-scale research in the MASC from 2004 to 2021 were collated (a total of 16 research sites and 70 data), as well as the storage and water-holding characteristics of litters of three typical forests in the MASC were compared and analyzed. The results showed that the water-holding processes of litter in coniferous forest, broadleaved forest and mixed forest were similar, which could be divided into three stages: rapid water absorption, gradual slowing, and stable. The absorption rate and duration of different forests were different in each stage. The broadleaved forest had the fastest water absorption rate, while coniferous forest had the slowest with the longest duration to reach stability. There was no significant difference in litter storage among diffe-rent forest types. The total litter storage of coniferous forest, broadleaved forest and mixed forest ranged from 8.26 to 8.82 t·hm-2. The significant spatial variations of litter storage in semi-decomposed layer resulted in that of total litter storage. The total maximum water-holding capacity of litters of the three forests ranged from 17.85 t·hm-2 to 19.87 t·hm-2, and the maximum water-holding rate of litter ranged from 200.6% to 228.0%. There was a positive correlation between the maximum water-holding capacity and litter storage in different forests. The total effective retention capacity of three forest litters ranged from 11.66 to 12.29 t·hm-2, while the total effective retention rate of three forests ranged from 128.1% to 145.2%. There were no significant differences in litter storage and water holding capacity among three forest types with two decomposition degrees in MASC.


Assuntos
Traqueófitas , Água , China , Ecossistema , Florestas , Solo , Árvores , Água/análise
11.
ACS Appl Mater Interfaces ; 14(27): 30872-30880, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35759400

RESUMO

Highly active catalysts with promising water retention are favorable for proton exchange membrane fuel cells (PEMFCs) operating under low-humidity/high-temperature conditions. When PEMFCs operate under low-humidity/high-temperature conditions, performance attenuation rapidly occurs owing to reduced proton conductivity of dehydrated membrane electrode assemblies. Herein, we load platinum onto a perovskite-carbon joint substrate (BaZr0.1Ce0.7Y0.1Yb0.1O3-σ-XC-72R) to construct a highly active and durable catalyst with good water retention capacity. We propose that the Pt/(BZCYYb-C) catalyst layer at cathode can promote the water back diffusion of produced water from the cathode to the membrane, thus preventing the decay of fuel-cell performance under low-humidity/high-temperature conditions. The catalyst exhibited outstanding mass activity of 0.542 A mgpt-1 at 0.9 V vs RHE. PEMFCs with such a catalyst delivered very high peak power densities (1.70/1.14 W cm-2 under H2-O2/air conditions at 70 °C) and kept 85.3%/92.1% of initial performance values under low-humidity/high-temperature conditions (relative humidity 60%@70 °C/100 °C).

12.
Environ Sci Pollut Res Int ; 29(43): 64680-64691, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35476270

RESUMO

The leachate drainage volume (LDV) of municipal solid waste (MSW) landfills is crucial to the operation of leachate treatment plant and development at the leachate level, but there is still a lack of reasonable evaluation methods. In this study, the evaluation methods, including both field measurements and numerical simulations, are proposed and applied in the case study of a MSW landfill in Southeastern China. For field measurements, 23 boreholes were drilled to test the leachate level distribution, and thus to determine the saturated volume (SV) of the landfill. The water retention capacity of the drilled samples was tested in a compression cell for a calculation of the undrainage volume (UV) of the landfill, and total LDV was obtained as SV-UV. The total LDV and SV were measured to be 2.31 × 105 m3 and 1.08 × 106 m3, respectively, which indicated a total leachate drainage percentage (LDV/SV) of 22%. For numerical simulations, a hydro-mechanical model is established to predict the daily LDV during layered landfilling. The model couples leachate flow and MSW compression, which are two fundamental processes determining daily LDV. As the model takes into account the leachate generation caused by the compression of MSW, the prediction has a good agreement with the measurement. If ignoring compression, the daily LDV will be underestimated by a percentage of 35%-50%. This study provides basic information and an assessment framework of leachate drainage volume and contributes to leachate management in landfills.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Água , Poluentes Químicos da Água/análise
13.
Int J Biol Macromol ; 206: 534-542, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35235853

RESUMO

The addition of potato to wheat flour extends the nutritional values of bread. However, the adverse effects mediated by high dietary fiber in potato flour could affect the formation of gluten matrix. The water dynamics and distribution determined by the Low field nuclear magnetic resonance (LF-NMR) demonstrated a competitive water binding of dietary fiber, resulting in the partial dehydration and conformational changes of gluten protein complexes. Besides, the microstructure of the dough characterized by Scanning electron microscope (SEM) suggested that the insoluble cellulose could block the continuity of gluten from the spatial position, thereby negative affecting the mechanical properties of the dough. In our study, addition of cellulase and/or pectinase apparently mitigated the gluten aggregation and dehydration, contributing to the formation and the continuity of the three-dimensional gluten network. As a consequence, the specific volume of the bread was increased by 40.2%, and the hardness was reduced by 64.48%.


Assuntos
Farinha , Solanum tuberosum , Pão , Celulose , Desidratação , Fibras na Dieta , Glutens/química , Pectinas , Triticum/química , Água/química
14.
Heliyon ; 8(12): e12457, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36619451

RESUMO

The present study sought to detect the difference in physicochemical properties and the proximate compositions of common calcareous red seaweeds "Corallina officinalis, Jania rubens, and Amphiroa rigida". J. rubens was recorded highly water (WHC), and oil holding capacity (OHC) (1.619 ± 0.08 g g-1 DW, 3.1 ± 0.50 g g-1 DW, respectively) than those other species relating to the hydrophilic nature of polysaccharides, whereas swelling water capacity (SWC) was higher in A. rigida (5.25 ± 0.38 mL g-1 DW). A higher value of carbohydrates (49.88 ± 2.56% DW) was observed in J. rubens, Contrariwise, protein (36.99 ± 1.36% DW) and lipid contents (5.85 ± 0.49% DW) were higher in C. officinalis. Albumin and protamine protein fractions were higher in J. rubens specimens (45.11 ± 2.29 mg g-1 & 0.0014 ± 0.0007 mg g-1 DW, respectively) than other species. While globulin and glutilin (31.70 ± 1.90 mg g-1 DW & 41.93 ± 2.20 mg g-1 DW, respectively) were high in A. rigida. Contrariwise, insoluble protein fraction was high in C. officinalis (9.50 ± 0.50 mg g-1 DW). J. rubens specimens were recorded maximum values of the photosynthetic pigments. The different surface types and elemental analysis of three species were examined by Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). From fourier transform infrared (FTIR) spectroscopy the S-S stretching peak of disulfides group at 462 cm-1 was the fingerprint of J. rubens. From GC-MS data A.rigida possesses 16 bioactive components with biological properties. As a result, J. rubens and A. rigida could be employed as an ingredient in functional foods and drug manufacture.

15.
ACS Appl Mater Interfaces ; 13(50): 60084-60091, 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34889608

RESUMO

Crystalline porous materials, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), have been demonstrated to be versatile material platforms for the development of solid proton conductors. However, most crystalline porous proton conductors suffer from decreasing proton conductivity with increasing temperature due to releasing water molecules, and this disadvantage severely restricts their practical application in electrochemical devices. In this work, for the first time, hydrophilic carbon dots (CDs) were utilized to hybridize with high proton conductivity MOF-802, which is a model of MOF proton conductors, aiming to improve its water-retention capacity and thus enhance proton conduction. The resultant CDs@MOF-802 exhibits impregnable proton conduction with increasing temperature, and the proton conductivity reaches 10-1 S cm-1, much superior to that of MOF-802, making CDs@MOF-802 one of the most efficient MOF proton conductors reported so far. This study provides a new strategy to improve the water-retention capacity of porous proton conductors and further realize excellent proton conduction.

16.
J Environ Manage ; 289: 112461, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33831758

RESUMO

The application of compost has been recognized as one of the most promising approaches for preserving soil quality and crop production. The present study exhaustively investigates the impact of Water Hyacinth Compost (WHC), Hydrilla verticillata Compost (HVC) and Vegetable Waste Compost (VWC) on soil nutrient quality and engineering properties [Bulk Density (BD), water retention and specific gravity]. For the study, six different proportions constituting 5, 10, 15, 25, 35 and 45% of the composts by weight of the soil were taken. The soil compost mixtures were evaluated at different periods (0, 15, 30, 45, 60 and 120 days) for various nutrients [Na, Mg, P, K, Ca, Total Organic Carbon (TOC), Total Kjeldahl Nitrogen (TKN)], BD, water retention capacity, change in specific gravity and Cation Exchange Capacity (CEC) values. It was observed that when the percentage of compost was increased to 15-45%, it resulted in enhanced nutrient value of the soil. Also, for WHC, HVC and VWC 60 days was sufficient to improve the soil quality to its maximum extend. Based on the optimized physico-chemical properties generated from the Response Surface Methodology (RSM) model, it was found that compared to WHC and HVC, the VWC performed better results viz., generating low BD (0.87 g/cm3), high water retention capacity (45.63%) and degree of saturation (77.49%) of the soil. While WHC, HVC and VWC can be used to improve soil nutrient content and overall physico-chemical parameters in long terms, VWC could be more efficient and beneficial to degraded soil for restoring soil health.


Assuntos
Compostagem , Hydrocharitaceae , Nitrogênio/análise , Nutrientes , Solo
17.
J Environ Manage ; 271: 110959, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579520

RESUMO

The conversion of poultry litter to hydrochar has been proposed for stabilization of the soils and to eliminate pathogens. Still, research on the hydrochar's effect on soil properties as a function of production temperature, and its direct use with plants is limited in general and even less so on poultry litter. We characterized poultry litter hydrochar as an amendment for sandy soils in terms of changes to the soil's bulk density, porosity, water-retention capacity, and fertility. Soil bulk density, porosity and water-retention capacity were determined in a pneumatic tension plate system for sand with hydrochar-amendment rates of 0.5, 1 and 2%, and hydrochar-production temperature of 180, 220, and 250 °C. Soil fertility was assessed by growing lettuce seedlings in a randomized block design planter experiment, consisting of 16 blocks that were sampled every 10 days. The addition of poultry litter hydrochar resulted in decreased soil bulk density. Soil porosity increased with hydrochar generated at a temperature of up to 220 °C, and decreased with hydrochar generated at 250 °C. Soil water content increased as compared to unamended sand, but decreased with increasing hydrochar-production temperature, probably due to increasing hydrophobicity of the poultry litter hydrochar. The addition of hydrochar at concentrations of 0.5 and 1% resulted in improved plant growth despite an initial delay. While increased soil moisture due to increased soil water-retention capacity was confirmed, it did not seem to be responsible for the improved plant growth. It was also demonstrated for the first time that hydrochar decreases nitrate leaching from soils. Therefore, poultry litter-derived hydrochar seems to be an adequate amendment for sandy soils.


Assuntos
Aves Domésticas , Solo , Animais , Esterco , Areia , Temperatura
18.
Carbohydr Polym ; 241: 116262, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32507220

RESUMO

The effect of wheat bran on starch gelatinization temperature was investigated. Dynamic water vapour sorption and water retention capacity experiments showed that bran bound up to 3 times more water than starch. However, examining starch gelatinization in starch-bran-water mixtures with differential scanning calorimetry showed that the effect of substituting starch by bran differed from that of moving into a regime of limiting water. Modelling the effect of the mixture composition on starch gelatinization behavior indicated that the onset (To) and peak (Tp) gelatinization temperatures were positively impacted by the bran concentration in water. The conclusion temperature (Tc) was negatively affected by the water content. Fractionation experiments demonstrated that the increased To and Tp were mainly caused by the extractable wheat bran components, such as potassium and phosphorus, which decrease the plasticization capacity of the solvent. The mechanism behind our observations was explained with the side-chain liquid-crystalline polymeric model for starch.


Assuntos
Fibras na Dieta , Gelatina/química , Amido/química , Varredura Diferencial de Calorimetria , Temperatura , Triticum , Água/química
19.
Food Chem ; 325: 126828, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32413686

RESUMO

The molecular mobility of water and biopolymers in wheat dough and the influence of xylanases thereon was investigated with time domain proton nuclear magnetic resonance relaxometry. To reduce the complexity, model systems containing starch, gluten and/or water-unextractable arabinoxylan (WU-AX) were used. In the starch-WU-AX-water model, starch binds water fast but less strong compared to WU-AX, resulting in water withdrawal from starch during resting. In contrary, WU-AX did not affect the water distribution in a gluten-WU-AX-water system, despite the higher water retention capacity (WRC) of WU-AX compared to gluten. In a starch-gluten-WU-AX-water model and in wheat flour, water was distributed over the different constituents including WU-AX. Addition of xylanase reduced the WRC of WU-AX, resulting in a release of water. Therefore, the beneficial effect of xylanase on dough and bread quality can, in part, be attributed to the redistribution of water, initially bound by WU-AX, between the other flour constituents.

20.
Food Chem ; 305: 125436, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514047

RESUMO

The physicochemical properties of wheat bran have an effect on its technofunctional and nutritional profile. The possibility to induce physicochemical modifications in wheat bran using microfluidisation was investigated. An I-optimal experimental design was used to investigate the effect of microfluidisation processing parameters (pressure, number of passes, bran concentration and initial particle size) on important properties of wheat bran (particle size, microstructure, chemical composition, water retention capacity (WRC), extractability, viscosity and sedimentation). With the parameters used in this study, microfluidisation reduced wheat bran median particle size to 14.8 µm and disintegrated starch granules from the attached endosperm. This coincided with an increased extractability of starch and arabinoxylan. While the initial particle size was of minor importance, a higher pressure, larger number of passes and lower bran concentration during microfluidisation resulted in a smaller particle size, higher WRC and extractability, and an increased viscosity and stability in a 2% wheat bran suspension.


Assuntos
Fibras na Dieta/análise , Triticum/química , Endosperma/química , Tamanho da Partícula , Amido , Viscosidade , Água , Xilanos
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