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1.
Food Chem ; 332: 127399, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645676

RESUMO

Different baking conditions were used in order to evaluate its effects on bread aspects. Doughs were baked at 160, 190 and 220 °C, during 9, 12, 15 and 20 min, and characterized in relation to color change, oxalate and mineral concentration, and protein digestibility. The higher the baking temperature and time, the higher the crust color change, the lower the oxalate concentration, and the higher the amount of some macro minerals. Protein digestibility may also be favored, however it does not follow a linear correlation. Although it is not possible to obtain a condition that favors the content of all minerals, protein digestibility and reduces oxalate content, the use of high temperatures and times is important as it can reduce oxalate and thereby prevent its associated problems. Understanding how to optimize it during baking could be used to produce breads with a higher mineral bioavailability, an important strategy for food industry and also when using alternative flours.


Assuntos
Pão/análise , Digestão , Manipulação de Alimentos/métodos , Minerais/análise , Oxalatos/análise , Proteínas de Plantas/química , Triticum/química , Farinha/análise , Temperatura Alta , Proteínas de Plantas/metabolismo
2.
Food Chem ; 332: 127422, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623129

RESUMO

During wheat cultivation, glyphosate-based herbicides are recommended to be applied a week prior to harvest during the ripe stage of physiological maturity. However, some grains may not be at this physiological stage due to non-uniform maturation within the field. The goal of this study was to determine the effect of glyphosate-based herbicide timing on the chemistry of wheat gluten proteins and shikimic acid accumulation. The results of the study indicate that pre-harvest glyphosate application does not impact the amino acid composition, protein secondary structure or gluten protein composition. However, pre-harvest glyphosate application decreased the molecular weight of SDS extractable and unextractable proteins, and significantly increased the amount of shikimic acid accumulation, especially when applied early. Thus, this study indicates that pre-harvest use of glyphosate-based herbicides can cause significant differences in wheat protein chemistry and shikimic acid levels, especially when applied earlier than recommended, emphasizing the importance of timely application.


Assuntos
Glicina/análogos & derivados , Herbicidas/farmacologia , Proteínas de Plantas/metabolismo , Ácido Chiquímico/metabolismo , Triticum/efeitos dos fármacos , Aminoácidos/análise , Aminoácidos/metabolismo , Glutens/análise , Glutens/metabolismo , Glicina/farmacologia , Proteínas de Plantas/análise , Ácido Chiquímico/análise , Triticum/química , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
3.
Food Chem ; 332: 127434, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645669

RESUMO

The baking in N2 and CO2 atmosphere decreased by 50% the acrylamide, while this level was 99% in SO2. The highest acrylamide content was detected in the control sample as 39.03 µg/kg. Additionally, the lowest HMF content was determined in S-bread as 14.85 mg/kg. The baking atmosphere has a significant impact on L* and a* colour values of bread. The highest L* value was measured in S-bread as 71.2, whereas it was the lowest in the control sample as 49.1. According to the Pearson results, acrylamide showed a negative correlation between L* value. However, no correlation was detected between colour values and HMF. Acrylamide had a positive correlation with flavour, although it did not affect the taste features of bread. No correlation between HMF and sensory properties was determined. The result of the study suggested that inert or inhibitor baking atmosphere may help prevent the Maillard reactions in bakery products.


Assuntos
Acrilamida/química , Pão/análise , Culinária/métodos , Furaldeído/análogos & derivados , Farinha/análise , Furaldeído/química , Temperatura Alta , Humanos , Reação de Maillard , Paladar , Triticum/química
5.
PLoS One ; 15(7): e0236317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702002

RESUMO

Heterodera avenae, as an obligate endoparasite, causes severe yield loss in wheat (Triticum aestivum). Investigation on the mechanisms how H. avenae perceives wheat roots is limited. Here, the attractiveness of root exudates from eight plant genotypes to H. avenae were evaluated on agar plates. Results showed that the attraction of H. avenae to the root exudates from the non-host Brachypodium distachyon variety Bd21-3 was the highest, approximately 50 infective second-stage juveniles (J2s) per plate, followed by that from three H. avenae-susceptible wheat varieties, Zhengmai9023, Yanmai84 and Xiangmai25, as well as the resistant one of Xinyuan958, whereas the lowest attractive activity was observed in the two H. avenae-resistant wheat varieties, Xianmai20 (approximately 12 J2s/plate) and Liangxing66 (approximately 11 J2s/plate). Then Bd21-3, Zhengmai9023 and Heng4399 were selected for further assays as their different attractiveness and resistance to H. avenae, and attractants for H. avenae in their root exudates were characterized to be heat-labile and low-molecular compounds (LM) by behavioral bioassay. Based on these properties of the attractants, a principle of identifying attractants for H. avenae was set up. Then LM of six root exudates from the three plants with and without heating were separated and analyzed by HPLC-MS. Finally, dihydroxyacetone (DHA), methylprednisolone succinate, embelin and diethylpropionin in the root exudates were identified to be putative attractants for H. avenae according to the principle, and the attraction of DHA to H. avenae was validated by behavioral bioassay on agar. Our study enhances the recognition to the orientation mechanism of H. avenae towards wheat roots.


Assuntos
Di-Hidroxiacetona/química , Doenças das Plantas/parasitologia , Raízes de Plantas/química , Triticum/química , Animais , Brachypodium/genética , Brachypodium/parasitologia , Di-Hidroxiacetona/fisiologia , Resistência à Doença/genética , Resistência à Doença/fisiologia , Genótipo , Doenças das Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/parasitologia , Raízes de Plantas/fisiologia , Triticum/genética , Triticum/parasitologia , Triticum/fisiologia , Tylenchoidea/genética , Tylenchoidea/patogenicidade
6.
PLoS One ; 15(7): e0236634, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706842

RESUMO

Potassium (K) input is essential for the improvement of soil fertility in agricultural systems. However, organic amendment may differ from mineral K fertilization with respect to modifying the soil K transformation among different fractions, affecting soil K availability. We conducted a 60-day lab incubation experiment to evaluate the response of soil K dynamics and availability in various fractions with a view to simulating crop residue return and chemical K fertilization in an Anthrosol of northwest China. The tested soil was divided into two main groups, no K fertilization (K0) and K fertilization (K1), each of which was subjected to four straw addition regimes: no straw addition (Control), wheat straw addition (WS), maize straw addition (MS), and both wheat straw and maize straw addition (WS+MS). Soil K levels in the available (AK) and non-exchangeable (NEK) fractions were both significantly increased after K addition, following the order of K>WS>MS. Fertilizer K was the most efficient K source, demonstrating a 72.9% efficiency in increasing soil AK, while wheat and maize straw exhibited efficiencies of 47.1% and 39.3%, respectively. Furthermore, K fertilization and wheat and maize straw addition increased the soil AK in a cumulative manner when used in combination. The mobility factor (MF) and reduced partition index (IR) of soil K were used to quantitate the comprehensive soil K mobility and stability, respectively. Positive relationships were observed between the MF and all relatively available fractions of soil K, whereas the IR value of soil K correlated negatively with both MF and all available fractions of soil K. In conclusion, straw amendment could be inferior to mineral K fertilization in improving soil K availability when they were almost equal in the net K input. Crop straw return coupled with K fertilization can be a promising strategy for improving both soil K availability and cycling in soil-plant systems.


Assuntos
Agricultura , Potássio/química , Solo/química , Triticum/metabolismo , Zea mays/metabolismo , China , Fertilizantes/análise , Potássio/metabolismo , Análise de Componente Principal , Triticum/química , Zea mays/química
7.
Int J Food Microbiol ; 331: 108712, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32563775

RESUMO

The bread-making quality of wheat depends on the viscoelastic properties of the dough in which gluten proteins play an important role. The quality of gluten proteins is influenced by the genetics of the different wheat varieties and environmental factors. Occasionally, a near complete loss of gluten strength, measured as the maximum resistance towards stretching (Rmax), is observed in grain lots of Norwegian wheat. It is hypothesized that the loss of gluten quality is caused by degradation of gluten proteins by fungal proteases. To identify fungi associated with loss of gluten strength, samples from a selection of wheat grain lots with weak gluten (n = 10, Rmax < 0.3 N) and strong gluten (n = 10, Rmax ≥ 0.6 N) was analyzed for the abundance of fungal operational taxonomic units (OTUs) using DNA metabarcoding of the nuclear ribosomal Internal Transcribed Spacer (ITS) region ITS1. The DNA quantities for a selection of fungal pathogens of wheat, and the total amount of fungal DNA, were analyzed by quantitative PCR (qPCR). The mean level of total fungal DNA was higher in grain samples with weak gluten compared to grain samples with strong gluten. Heightened quantities of DNA from fungi within the Fusarium Head Blight (FHB) complex, i.e. Fusarium avenaceum, Fusarium graminearum, Microdochium majus, and Microdochium nivale, were observed in grain samples with weak gluten compared to those with strong gluten. Microdochium majus was the dominant fungus in the samples with weak gluten. Stepwise regression modeling based on different wheat quality parameters, qPCR data, and the 35 most common OTUs revealed a significant negative association between gluten strength and three OTUs, of which the OTU identified as M. majus was the most abundant. The same analysis also revealed a significant negative relationship between gluten strength and F. avenaceum detected by qPCR, although the DNA levels of this fungus were low compared to those of M. majus. In vitro growth rate studies of a selection of FHB species showed that all the tested isolates were able to grow with gluten as a sole nitrogen source. In addition, proteins secreted by these fungi in liquid cultures were able to hydrolyze gluten substrate proteins in zymograms, confirming their capacity to secrete gluten-degrading proteases. The identification of fungi with potential to influence gluten quality can enable the development of strategies to minimize future problems with gluten strength in food-grade wheat.


Assuntos
Microbiologia de Alimentos , Fungos/classificação , Glutens/química , Triticum/química , Triticum/microbiologia , DNA Fúngico/genética , Grão Comestível/microbiologia , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Glutens/metabolismo , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Triticum/metabolismo
8.
Food Chem ; 330: 127328, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32569940

RESUMO

Granular protein is an important structural feature in determining starch digestibility. High-amylose wheat starch (HAWS) with >80% amylose content contains more granular protein than wild-type starch. As analyzed by mass spectrometry-based proteomics, granular-bound starch synthase (GBSS) is the major granular protein in isolated starch materials. GBSS content increases with amylose content (Spearman's correlation, p < 0.05), whereas the abundance relative to other proteins is similar among starches. Multiple amylase inhibitors were also identified. From Michaelis-Menten analysis, HAWS has a similar Km (Michaelis constant) as wild type, suggesting initial enzymatic binding is similar. After the pre-digestion of proteins, wild type had a greater change in starch digestibility than HAWS, probably due to the latter having 'thicker' granular-protein layers and higher enzymatic resistance of substrate per se. Overall, the study suggests that the greater granular protein content in HAWS is a factor that contributes to slower amylolysis compared to wild type.


Assuntos
Amilose/metabolismo , Proteínas de Plantas/metabolismo , Sintase do Amido/metabolismo , Amido/química , Triticum/química , Amilose/análise , Amilose/química , Digestão , Hidrólise , Cinética , Proteínas de Plantas/análise , Amido/metabolismo , Sintase do Amido/análise , Espectrometria de Massas em Tandem , Triticum/metabolismo , alfa-Amilases/química , alfa-Amilases/metabolismo
9.
Food Chem ; 331: 127315, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32593039

RESUMO

The effects of frying temperature on the properties of wheat starch were investigated, including the microstructure, weight-average molar mass (Mw), crystalline properties, functional groups, in vitro digestibility, static rheological properties, swelling power and solubility. SEM micrographs showed that the disc-shaped starch granules ruptured after being fried, and formed a continuous and dense gel structure. With the increasing frying temperature, the starch molecules underwent violent degradation, and the Mw decreased from 3.04 × 107 g/mol to 0.80 × 107 g/mol. The XRD and FTIR data indicated the formation of starch-lipid complexes during the frying process. In vitro digestion analysis revealed that the digestion rate of starch decreased, while the content of resistant starch (RS) increased after being fried. Besides, the shear stability of fried starch increased, whereas its swelling power and solubility decreased. These significant variations in physicochemical properties of starch could provide scientific basis for further improving the quality of instant noodles.


Assuntos
Culinária , Digestão , Reologia , Amido/química , Triticum/química , Lipídeos/química , Peso Molecular , Solubilidade , Amido/metabolismo , Temperatura
10.
Food Chem ; 330: 127154, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531630

RESUMO

Dextran-containing sourdough has been exploited in breadmaking, obtaining additive-free bread of high quality. Effect of dextran, weak acidification and their association on gluten dough structure, thermal properties and rheology was investigated. Electrophoresis (SDS-PAGE) showed that dextran and acids both lowered the band intensity in the high molecular weight area (Mw > 175 kDa) and size exclusion (SE-HPLC) revealed that weak acidification induced a decrease of 4.73% of the glutenin macropolymer (GMP) content. The higher free thiol (SH) was observed after dextran addition, further suggesting the hindered glutenin polymerization. Fourier transform infrared spectroscopy (FTIR) found that dextran and weak acidity caused increased ß-turn and decreased ß-sheet structures, suggesting a gluten of lower coherence and resistance to extension. Weakened thermal stability and viscoelasticity were subsequently detected by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic rheology. However, structural, thermal and rheological properties of the weakly acidified group were improved by the associated dextran.


Assuntos
Dextranos/química , Glutens/química , Varredura Diferencial de Calorimetria , Concentração de Íons de Hidrogênio , Polimerização , Reologia , Triticum/química , Viscosidade
11.
Food Chem ; 330: 127156, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531631

RESUMO

Rice bran (RB) and wheat bran (WB) fermented with L. plantarum 423 had enhanced odor intensity, especially for sulfides and aromatics. The hydroxyl radical-scavenging activity (73.28 ± 3.18%) and oxygen radical-scavenging activity (2.12 ± 0.08 mmol·TE/g) of RB fermentation broth were better than those of WB fermentation broth. Even at 2 µg/ml, the purified antioxidant fractions from the WB fermentation broth showed strong intracellular ROS-scavenging activity in human umbilical vein endothelial cells (HUVECs), and the purified antioxidant fractions (200 µg/ml) from the RB fermentation broth had a good antiaging effect. The dominant antioxidant components in the RB and WB fermentation broths were acids (70.21%) and ketones (10.64%), these components jointly give the RB and WB fermentation broths a variety of antioxidant properties. These results are beneficial for developing RB and WB deep-processing technology and laid the foundation for the preparation of antioxidant fractions with L. plantarum 423.


Assuntos
Antioxidantes/farmacologia , Fibras na Dieta/metabolismo , Fermentação , Aromatizantes/análise , Lactobacillus plantarum/metabolismo , Oryza/metabolismo , Triticum/metabolismo , Antioxidantes/isolamento & purificação , Células Cultivadas , Nariz Eletrônico , Células Endoteliais/efeitos dos fármacos , Aromatizantes/isolamento & purificação , Humanos , Oryza/química , Triticum/química
12.
Food Chem ; 330: 127212, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32526650

RESUMO

In this work, a facile solid phase extraction (SPE) method was developed for the analysis of trace Pb2+ and Cd2+ by using chitosan/thiol modified metal-organic frameworks (CS/MOF-SH) composite as adsorbent followed by graphite furnace atomic absorption spectrometer (GF-AAS) detection. The potential influencing factors, such as solution pH, adsorbent dosage, and extraction time, were fully estimated. Under the optimized extraction conditions, the detection limits of Pb2+ and Cd2+ were 0.033 µg L-1 and 0.008 µg L-1, respectively. Compared to other studies, CS/MOF-SH not only possessed superior adsorption performance, but also had the advantages of ease of handling and recyclability. Encouragingly, the developed method was of high accuracy and could monitor trace Pb2+ and Cd2+ in various certified reference materials (rice, wheat and tea) with complicated matrices, demonstrating its practical potential for regular monitoring of trace heavy metal ions in real food samples.


Assuntos
Cádmio/análise , Quitosana/química , Chumbo/análise , Estruturas Metalorgânicas/química , Compostos de Sulfidrila/química , Cádmio/química , Cátions Bivalentes , Análise de Alimentos , Chumbo/química , Oryza/química , Extração em Fase Sólida/métodos , Chá/química , Triticum/química
13.
Food Chem ; 329: 126800, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32504915

RESUMO

The role of polyphenol oxidase (PPO) in the browning of fresh wet noodle sheets (FWNS) was discussed. To release the chemical formation mechanism of the dark spots formed on FWNS, the reconstituted FWNS and PPO-catechol reaction systems were prepared. Different from the overall color change of FWNS, almost all the melanins in dark spots were indirect products of PPO catalysis. The PPO catalytic dehydrogenation was an essential step for the formation of dark spots, but once the phenol dehydrogenation products were formed, the dark spots could still form through a further polymerization process, even though the PPO was completely deactivated. The optimum pH for the phenolic dehydrogenation in FWNS was about 7, and the alkaline condition was advantageous to the progress of the polymerization. Comprehensively, the maximum amount of dark spots was formed at about pH 9.


Assuntos
Catecol Oxidase/metabolismo , Alimentos , Cor , Farinha/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio , Fenóis/análise , Fenóis/metabolismo , Triticum/química
14.
Ecotoxicol Environ Saf ; 202: 110886, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32585487

RESUMO

A field investigation was conducted to study the dynamic distribution and accumulation of polycyclic aromatic hydrocarbons (PAHs) in winter wheat in the surrounds of a coal-fired power plant. During March to June 2019, various tissues of winter wheat and the corresponding rhizosphere soil were collected for determination of PAHs. A clear spatial downward trend was found in concentration of Σ15PAHs in rhizosphere soil and wheat grain (194-237 µg kg-1 DM) with the increasing distance from the coal-fired power plant. Moreover, Σ15PAHs concentration in rhizosphere soil (1081 µg kg-1 DM), root (464 µg kg-1 DM) and stem (365 µg kg-1 DM) of winter wheat at regreening stage and leaf (323 µg kg-1 DM) at anthesis stage were significantly (p < 0.001) higher than that (895, 432, 287 and 265 µg kg-1 DM) at maturity stage, respectively. From regreening to maturity stage, root concentration factors (RCF) of 3- and 4-ring PAHs exhibited an increasing trend but the 5-ring PAHs showed an apparently downward trend. However, stem concentration factors (SCF) of 3- and 4-ring PAHs showed a decrease trend while the 5- and 6-ring showed first down and then stable trend. There were positive linear relationship between logKow and logSCF at anthesis (r = 0.681, p < 0.05) and maturity stage (r = 0.751, p < 0.05). Based on linear regression analysis, PAHs in grain mainly came from the transfer of vegetative tissues, and the contribution of PAHs from stem and leaf to grain was higher than that from root. In addition, the present study also found that the physicochemical properties of PAHs play a crucial role in transfer of PAHs from root to vegetative tissues and then to grain. The present research provided more comprehensive information on the fate of PAHs in winter wheat and the safety of the agricultural products.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Triticum/química , Agricultura , Grão Comestível/química , Desenvolvimento Vegetal , Folhas de Planta/química , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Estações do Ano , Solo/química , Poluentes do Solo/metabolismo , Triticum/metabolismo
15.
Food Chem ; 326: 126972, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32422510

RESUMO

Different bread formulations, which provide different dough structures, were studied in order to better understand the effect of wheat flour substitution, flour type and concentration on dough development during baking, and their relationship with physical properties of the final product. Breads were produced with partial substitution of wheat flour by corn (CF), green banana (GF) and rice flour (RF), at different concentrations, and then baked at different times. Wheat flour substitution by CF, GF and RF in bread reduces heat transfer to the dough center by about 21%, 35% and 20%, respectively; and the water loss by about 5%, 15% and 0%, respectively. Those reductions were more influenced by flour type, than flour concentration. When wheat flour is substituted, the mechanisms of water migration are modified, once the pore system of bread dough is more discrete and stiffens later. Calculated thermal conductivity and diffusivity of the different flours used, and its correlations with average composite-bread heating rates (0.93) and water loss (0.85), respectively, indicates that thermal properties of composite bread dough could represent an important issue to be explored in dough systems with reduced gluten concentration.


Assuntos
Pão , Farinha , Musa , Oryza , Zea mays , Glutens/análise , Musa/química , Oryza/química , Temperatura , Triticum/química , Água , Zea mays/química
16.
Food Chem ; 328: 127111, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32470777

RESUMO

Wheat millstreams and wheat-based foods (pasta, biscuits and bread) enriched or not in dietary fibre with fractions extracted from wheat grains, have been characterized either for their total dietary fibre content (TDF) and their arabinoxylan (AX) content. A strong correlation (r2 = 0.98) is observed between the AX and TDF contents indicating that AX can be used to estimate TDF content in wheat products. Moreover, by adding a previous step including enzymatic hydrolysis with a xylanase, a functional evaluation of DF is proposed based on the amount of AX released by the enzyme. Xylanase hydrolysable AX are likely also released by microbiota's enzymes in the gut and therefore an indicator for the proportion of fermentable DF in grain fractions and wheat-based foods (pasta, biscuits and bread). This assay opens the door for simple characterization of qualitative attribute of cereal DF.


Assuntos
Fibras na Dieta/análise , Triticum/química , Xilanos/análise , Pão/análise , Fibras na Dieta/metabolismo , Fermentação , Hidrólise , Sementes/química , Xilanos/metabolismo , Xilosidases/metabolismo
17.
Food Chem ; 327: 127011, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32438263

RESUMO

Wheat is one of the main dietary sources for mycotoxins that can cause adverse health effects in humans. Here we report results of a 3-year survey which compared the effects of flour type (whole-grain vs white), wheat species (common vs spelt), and farming system (organic vs conventional) on mycotoxin concentrations in UK and German wheat flour brands. Wholegrain, conventional and organic flour contained 124, 31 and 9% higher concentrations of T-2/HT-2, DON and ZEA respectively, but concentrations of the three Fusarium mycotoxins assessed were ~10 times lower than the EC-maximum contamination levels (MCL). Thirty one percent of flour samples had Ochratoxin A (OTA) concentrations above the MCL (3 µg/kg), but OTA levels were no affected by wheat species, farming system and flour type. Results suggest that both organic and conventional primary production methods and postharvest quality assurance systems are effective for maintaining Fusarium mycotoxins, but not OTA concentrations, below the MCL.


Assuntos
Agricultura/métodos , Farinha/análise , Contaminação de Alimentos/análise , Micotoxinas/análise , Triticum/química , Fusarium , Alemanha , Humanos , Ocratoxinas/análise , Agricultura Orgânica , Inquéritos e Questionários , Reino Unido , Grãos Integrais/química
18.
Food Chem ; 327: 127048, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32454285

RESUMO

In our previous study, a novel LMW-GS designated as LMW-N13 with a unique molecular structure was identified from Aegilops uniaristata. LMW-N13 has been characterized as the largest LMW-GS, so far, and possesses an extra cysteine residue compared with typical LMW-GS. In order to analyze the contribution of LMW-N13 to dough quality, in this work, three transgenic wheat lines overexpressing LMW-N13 were generated. Compared with non-transformation (NT) lines, transgenic (TG) lines demonstrated superior dough properties. These superior dough properties were accompanied by the higher contents of glutenin macropolymer (GMP) and total protein. The microstructure of the dough was further investigated by scanning electron microscopy; starch granules in NT lines were smaller than those in transgenic lines. The protein matrix in NT lines was relatively loose and discontinuous. Conversely, the protein matrix in transgenic lines was more continuous and tight. The application of LMW-N13 in wheat breeding is also discussed.


Assuntos
Farinha/análise , Glutens/química , Plantas Geneticamente Modificadas/química , Triticum/química , Aegilops/genética , Dissulfetos/química , Glutens/genética , Glutens/metabolismo , Microscopia Eletrônica de Varredura , Peso Molecular , Plantas Geneticamente Modificadas/metabolismo , Amido/química , Triticum/metabolismo , Água/química
19.
Chemosphere ; 252: 126522, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32443262

RESUMO

There is limited research on the effects of gut microbiota on bioaccessibility of heavy metals in wheat grains. In this study, bioaccessibility of heavy metals (Cu, Cd, Pb, and Zn) in wheat was determined to elucidate transfer characteristics in the soil-grain-human systems near two large-scale mining areas in Shandong Province, North China using the physiologically-based extraction test (PBET) in combination with a simulator of human intestinal microbial ecosystems (SHIME). The results showed the bioconcentration factors (BCFs) of Cu, Cd, Pb, and Zn were 0.123-0.327, 0.188-0.478, 0.019-0.099, and 0.262-0.825, respectively. Significant and positive correlations were observed between heavy metals in soils and wheat grains. In the simulated colon phase, bioaccessibility of Cd and Zn significantly decreased to 7.81% and 8.81%, respectively, being 53% and 64% of that in the simulated small intestinal phase. However, bioaccessibility of Pb showed an obvious escalating trend, being 2.4 times higher than that of intestinal incubation. Based on the estimated daily intakes and contribution, the relative high contribution of Cu to the benchmark dose in both phases, Cu metabolism by human gut microbiota should be considered in human health risk assessment regarding wheat consumption.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Mineração , Triticum/química , China , Ecossistema , Grão Comestível/química , Humanos , Medição de Risco , Solo , Poluentes do Solo/análise , Triticum/metabolismo
20.
PLoS One ; 15(5): e0232425, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365065

RESUMO

The aim of this work was to evaluate the impact of incorporating different legume flours (faba bean, lentil or split pea flours) on the pasta protein network and its repercussion on in vitro protein digestibility, in comparison with reference dairy proteins. Kinetics and yields of protein hydrolysis in legume enriched pasta and, for the first time, the peptidomes generated by the pasta at the end of the in vitro gastric and intestinal phases of digestion are presented. Three isoproteic (21%) legume enriched pasta with balanced essential amino acids, were made from wheat semolina and 62% to 79% of legume flours (faba bean or F-pasta; lentil or L-pasta and split pea or P-pasta). Pasta were prepared following the conventional pastification steps (hydration, mixing, extrusion, drying, cooking). Amino acid composition and protein network structure of the pasta were determined along with their culinary and rheological properties and residual trypsin inhibitor activity (3-5% of the activity initially present in raw legume flour). F- and L-pasta had contrasted firmness and proportion of covalently linked proteins. F-pasta had a generally weaker protein network and matrix structure, however far from the weakly linked soluble milk proteins (SMP) and casein proteins, which in addition contained no antitrypsin inhibitors and more theoretical cleavage sites for digestive enzymes. The differences in protein network reticulation between the different pasta and between pasta and dairy proteins were in agreement in each kinetic phase with the yield of the in vitro protein hydrolysis, which reached 84% for SMP, and 66% for casein at the end of intestinal phase, versus 50% for L- and P-pasta and 58% for F-pasta. The peptidome of legume enriched pasta is described for the first time and compared with the peptidome of dairy proteins for each phase of digestion. The gastric and intestinal phases were important stages of peptide differentiation between legumes and wheat. However, peptidome analysis revealed no difference in wheat-derived peptides in the three pasta diets regardless of the digestion phase, indicating that there was a low covalent interaction between wheat gluten and legume proteins.


Assuntos
Proteínas na Dieta/química , Proteínas na Dieta/farmacocinética , Proteínas de Plantas/química , Proteínas de Plantas/farmacocinética , Animais , Culinária , Digestão/fisiologia , Fabaceae/química , Farinha/análise , Alimentos Fortificados/análise , Humanos , Hidrólise , Técnicas In Vitro , Cinética , Lens (Planta)/química , Proteínas do Leite/química , Proteínas do Leite/farmacocinética , Valor Nutritivo , Ervilhas/química , Agregados Proteicos , Triticum/química , Vicia faba/química
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