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1.
Food Chem ; 351: 129303, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647689

RESUMEN

Herein, we investigated the impact of moist (steaming and boiling) and dry (baking and microwaving)-heat treatment processes on the structure and physicochemical properties of wheat starch (WS) supplemented with lauric acid (LA). Elemental composition analysis revealed the interplay between WS and LA. Scanning electron microscopy (SEM) and iodine staining revealed that lamellar crystalline structure of WS-LA complexes was improved after moist-heat treatment (relative to samples without any heat treatments); the finding which is at variance to dry-heat treatment process. Additionally, high resistance to thermal decomposition and a lower 1022/995 cm-1 absorbance ratio were observed in moist-heat treated WS-LA compared with dry-heat samples. Moreover, the V-type diffraction peak intensity and resistance to in vitro enzymatic hydrolysis of samples treated with moist-heat were increased to a greater extent than the dry-heat treated counterparts. In sum, this study would facilitate the application of functional starch-lipid complexes in food necessitated heat treatments.


Asunto(s)
Calor , Ácidos Láuricos/química , Almidón/química , Triticum/química , Digestión , Manipulación de Alimentos , Hidrólisis , Microscopía Electrónica de Rastreo , Almidón/metabolismo
2.
Nat Commun ; 12(1): 1708, 2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33731714

RESUMEN

Gluten, which makes up 85% of endosperm wheat protein, is considered a crucial quality determinant of wheat-based food products. During wheat dough manufacture, the molecular packing of gluten causes formation of large structures that exceed the millimetre scale. However, due to lack of imaging techniques for complex systems composed of giant macromolecules, the entire gluten structure remains unknown. Here, we develop an optical clearing reagent (termed SoROCS) that makes wheat-based products transparent. Combined with two-photon microscopy, we image the three-dimensional (3D) structure of gluten at the size in the millimetre scale and at submicron resolution. Further, we demonstrate how the 3D structure of gluten dramatically changes from a honeycomb-shaped network to sparse large clumps in wheat noodles, depending on the salt added during dough making, thereby reducing stress when compressing the noodle. Moreover, we show that SoROCS can be used for noodle imaging using confocal laser scanning microscopy.


Asunto(s)
Glútenes/química , Imagenología Tridimensional/métodos , Triticum/química , Microscopía Confocal , Microscopía de Fluorescencia por Excitación Multifotónica , Salicilato de Sodio/química , Solventes/química , Almidón/química
3.
Food Chem ; 352: 129307, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33691209

RESUMEN

Development of gluten-free products is important due to their role in gluten related disorders and health improvement. α-Amylase enzymes have shown to have a positive effect on wheat bread quality. This study aimed to screen in-silico a novel acidic-thermostable α-amylase (PersiAmy2) from the sheep rumen metagenome to increase the quality of gluten-free bread. The PersiAmy2 was cloned, expressed, purified and characterized. The enzyme was highly stable at a wide range of pH, temperature and storage conditions. The PersiAmy2 had excellent activity in the presence of ions, inhibitors, and surfactants. Utilization of the acidic thermostable PersiAmy2 in gluten-free bread resulted in a softer crumb, higher specific volume, porosity, moisture content and caused a darker crust color. The rheological measurement showed a solid-elastic behavior in batters. Also the addition of this enzyme reduced the firmness. From the results of this study it can be concluded that the PersiAmy2 can be used to improve the quality of gluten-free bread.


Asunto(s)
Pan/análisis , Dieta Sin Gluten , Metagenómica , Temperatura , alfa-Amilasas/metabolismo , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Reología , Triticum/química , Triticum/metabolismo
4.
Food Chem ; 352: 129323, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33691210

RESUMEN

In this study, functional snacks with addition of nanoenapsuated resveratrol were prepared to evaluate the nutraceutical and physical properties. The nanoencapsulated resveratrol was prepared from horse-chestnut (HRP), water-chestnut (WRP) and lotus-stem starch particles (LRP) and added to the wheat flour at the level of 0.4% for preparation of snacks by extrusing process. After extrusion, 43-53% and 5.42% of resveratrol was retained in snacks containing encapsulated and free resveratrol (FRP), respectively. The HRP, WRP and LRP showed significantly less peak viscosities and less elastic behaviour than native product (NP) which can influence the human sensory perception. The shift of few peaks towards higher wavelength and presence of additional peaks at 1384, 1229, 1513 and 1613 cm-1 depicts change in molecular pattern and presence of resveratrol in functional snacks. The functional snacks containing encapsulated resveratrol showed significantly higher antioxidant, anti-diabetic and anti-obesity properties than snacks containing no or free resveratrol.


Asunto(s)
Nanoestructuras/química , Resveratrol/química , Resveratrol/farmacología , Bocadillos , Fármacos Antiobesidad/química , Fármacos Antiobesidad/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Cápsulas , Harina/análisis , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Gusto , Triticum/química , Viscosidad
5.
Plant Sci ; 306: 110845, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33775355

RESUMEN

Cereal grains provide a substantial part of the calories for humans and animals. The main quality determinants of grains are polysaccharides (mainly starch but also dietary fibers such as arabinoxylans, mixed-linkage glucans) and proteins synthesized and accumulated during grain development in a specialized storage tissue: the endosperm. In this study, the composition of a structure localized at the interface of the vascular tissues of the maternal plant and the seed endosperm was investigated. This structure is contained in the endosperm cavity where water and nutrients are transferred to support grain filling. While studying the wheat grain development, the cavity content was found to autofluoresce under UV light excitation. Combining multispectral analysis, Fourier-Transform infrared spectroscopy, immunolabeling and laser-dissection coupled with wet chemistry, we identified in the cavity arabinoxylans and hydroxycinnamic acids. The cavity content forms a "gel" in the developing grain, which persists in dry mature grain and during subsequent imbibition. Microscopic magnetic resonance imaging revealed that the gel is highly hydrated. Our results suggest that arabinoxylans are synthesized by the nucellar epidermis, released in the cavity where they form a highly hydrated gel which might contribute to regulate grain hydration.


Asunto(s)
Endospermo/química , Endospermo/metabolismo , Triticum/química , Triticum/metabolismo , Xilanos/química , Xilanos/metabolismo , Grano Comestible/química , Grano Comestible/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier
6.
Food Chem ; 350: 129204, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33618086

RESUMEN

In this study, the ochratoxin A (OTA) interaction with some metal cations exhibits a quenching effect of the Cu2+, Co2+, and Ni2+ in the OTA intrinsic fluorescence intensity. The property of the OTA fluorescence change in complexation with the Cu2+ has been applied in developing a label-free and selective fluorimetric sensor for fast detection of the OTA trace amounts in wheat flour samples. The achieved color difference map (CDM) based on the spectral profile provides the technical support for the rapid visual sensing of OTA in the wheat flour samples. The feasibility of the hybrid fluorimetric sensor and visual OTA detection in wheat flour samples has been confirmed with the high-performance liquid chromatography (HPLC) method as a standard method. The calculated LOD (0.4 ng g-1) and LOQ (1.2 ng g-1) values of the proposed method are much lower than the maximum permissible limit of OTA value reported by the European Union (5 ng g-1).


Asunto(s)
Granjas , Harina/análisis , Contaminación de Alimentos/análisis , Ocratoxinas/química , Espectrometría de Fluorescencia/métodos , Triticum/química
7.
Food Chem ; 350: 129229, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33636619

RESUMEN

A new strategy to mimic antibody for electrochemical recognition and detection of deoxynivalenol (DON) using a highly-sensitive and selective antibody-like sensor based on molecularly imprinted poly(l-arginine) (P-Arg-MIP) on carboxylic acid functionalized carbon nanotubes (COOH-MWCNTs) was proposed. l-arginine as functional monomer was screened to prepare imprinted electrode via its electro-polymerization in the presence of DON onto the surface of COOH-MWCNTs electrode coupled with theoretical calculation. Surface morphology, structural characteristics, and electrochemical properties of P-Arg-MIP/COOH-MWCNTs were characterized by SEM, EDS, FTIR, and CV, respectively. P-Arg-MIP/COOH-MWCNTs displayed relatively high conductivity, high effective surface area, antibody-like molecular recognition and affinity, and a good response towards DON in a linear range from 0.1 to 70 µM with LOD of 0.07 µM in wheat flour samples with satisfactory recovery and feasible practicability in comparison with HPLC. This method provides a promising biomimetic sensing platform for the determination of mycotoxins in food and agro-products.


Asunto(s)
Biomimética/instrumentación , Límite de Detección , Impresión Molecular , Nanotubos de Carbono/química , Péptidos/química , Péptidos/síntesis química , Tricotecenos/análisis , Anticuerpos/inmunología , Electroquímica , Electrodos , Harina/análisis , Tricotecenos/química , Triticum/química
8.
Food Chem ; 349: 129155, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33548883

RESUMEN

This study aimed to evaluate cookies made with wheat (0%, 80%, 60%, and 50%) and tigernut flour (0%, 20%, 40%, and 50%) from two different sources. Standard methods were applied to determine the chemical properties, phenolic component, fatty acid composition, mineral content, and sensory properties of cookies. Tigernut flour from both sources was rich in oil, and total and individual phenolics, but with low antioxidant activity compared to wheat flour. The addition of tigernut flour to wheat resulted in increase of the content of bioactive compounds, minerals, and fatty acid contents of cookies. The cookies produced by formulating wheat with tigernut had a comparable organoleptic quality scores to wheat flour cookies. The production of cookies with both wheat and tigernut flour showed that this mixture is an interesting opportunity to have a functional product rich in bioactive compounds and considered satisfactory by consumers.


Asunto(s)
Antioxidantes/análisis , Harina/análisis , Valor Nutritivo , Gusto , Triticum/química , Humanos , Verduras/química
9.
Food Chem ; 348: 129017, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33582448

RESUMEN

Extruded wheat starch (ES) was obtained by a single-screw extruder to determine its effect on the farinograph, structural properties and baking behaviors of wheat dough. XRD analysis showed that increasing extrusion temperature made the crystalline peaks less pronounced due to the partial gelatinization. In terms of FTIR results, the molecular order of extruded starch was lower than that of native starch. The dough development time was decreased from 3.2 min to 2.7 min while the stability time was increased from 14.4 min to 15.5 min, as 70 ES were added. It was accompanied with increasing levels of α-helix and ß-turn transferred from the decreased content of random coil and ß -sheet. These effects in bread were to increase loaf volume and reduced loaf hardness. These results indicated that extruded starch had a good potential for producing a high-quality bread.


Asunto(s)
Culinaria , Harina/análisis , Almidón/química , Triticum/química , Pan/análisis , Dureza , Temperatura
10.
Food Chem ; 349: 129125, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33535111

RESUMEN

This study investigated the effect of germination time on compositional changes and functionality of whole wheat malt flour (WMF) as well as its influence on cookie quality. The results illustrated that malting resulted in decreases of starch, protein, fat and ash, while it increased dietary fiber, carbohydrate and energy. Gel hydration, emulsifying and foaming ability, pasting viscosity decreased significantly, particularly during the first 2 days of germination. Both bound and immobilized water in WMF decreased with increasing germination time while the concentration and antioxidant capacity of extractable and hydrolyzable phenolic compounds (EPP and HPP) increased significantly in WMF and malt-based cookies. Flours changed from an integrated granular to an irregular tousy structure during germination. The incorporation of WMF induced a distorted "honey-like" comb structure to the cookies. Conclusively, controlled germination not only improves the physicochemical, functional properties of WMF but also increases nutrition value and technological performance of malt-based cookies.


Asunto(s)
Antioxidantes/análisis , Germinación , Triticum/química , Triticum/crecimiento & desarrollo , Fibras de la Dieta/análisis , Harina/análisis , Valor Nutritivo , Fenoles/análisis , Almidón/análisis , Agua/química
11.
Food Chem ; 350: 129245, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33601091

RESUMEN

The co-occurrence of multiple pesticides in wheat fields adversely affects human health and the environment. Herein, 206 pairs of wheat and soil samples were collected from wheat fields in Beijing, China from 2018 to 2020. One or multiple pesticide residues were detected, and carbendazim (maximum: 38511.5 µg/kg) and tebuconazole (maximum: 45.4 µg/kg) had heavy occurrence in the wheat samples. Carbendazim, triazoles, and neonicotinoids were frequently detected in the soil samples. HCHs and DDTs were detected, with p,p'-DDE in 100.0% of the soil samples at a maximum concentration of 546.0 µg/kg in 2020. Concentrations of carbendazim, tebuconazole, hexaconazole, and cyhalothrin in the paired soil and wheat samples exhibited significant positive correlations. Pesticides that exceeded the maximum residue limits do not pose non-carcinogenic risks, with one exception. The results provide important references towards risk monitoring and control in wheat fields, as well as facilitating the scientific and reasonable use of these pesticides.


Asunto(s)
Exposición Dietética , Monitoreo del Ambiente/métodos , Plaguicidas/análisis , Contaminantes del Suelo/análisis , Triticum/química , Beijing , Humanos , Residuos de Plaguicidas/análisis , Plaguicidas/toxicidad , Medición de Riesgo , Contaminantes del Suelo/toxicidad
12.
Food Chem ; 350: 129259, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33621818

RESUMEN

Cereals and legumes are rich in folate. However, due to the instability of folate, processing and digestion can induce significant folate loss. In this paper, folate bioaccessibility of faba bean, oat, rye and wheat flours and pastes was studied using a static in vitro digestion model. Folate bioaccessibility depended on food matrices, varying from 42% to 67% in flours and from 40% to 123% in pastes. Digestion was associated with the interconversion of formyl folates, as well as the increase of oxidised vitamers and decrease of reduced vitamers. Especially in faba bean, 5-methyltetrahydrofolate showed surprisingly good stability both in digestion and heat treatment, resulting in high bioaccessibility. The physiological concentration of ascorbic acid did not stabilise folate in digestion; however, a higher level helped to maintain reduced vitamers. Heat treatment (10-min paste making) could improve folate bioaccessibility by liberating folate from the food matrices and by altering folate vitamer distribution.


Asunto(s)
Avena/química , Ácido Fólico/análisis , Secale/química , Triticum/química , Vicia faba/química , Disponibilidad Biológica , Digestión , Ácido Fólico/farmacocinética
13.
Food Chem ; 351: 129291, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33639427

RESUMEN

Bitterness is a common aversive flavor attribute of foods associated with low consumer acceptance. Untargeted LC-MS flavoromic profiling was utilized to identify endogenous compounds that influence the generation of the bitter compound 9,12,13-trihydroxy-trans-10-octadecenoic acid (pinellic acid) during bread making. A diverse sample set of wheat germplasm was chemically profiled. The corresponding pinellic acid concentrations after dough formation were modeled by orthogonal partial least squares (OPLS) with good fit (R2Y = 0.8) and predictive ability (Q2 = 0.6). The most predictive feature (negatively correlated), postulated to interfere with the biosynthetic pathway, was identified as schaftoside, an apigenin di-C-glycoside. Recombination experiments involving the addition of schaftoside to flour prior to breadmaking resulted in a 26% decrease in pinellic acid formation and significantly lower perceived bitterness intensity in whole wheat bread. This work provides novel understanding of bitter generation pathways in wheat products and new strategies to improve flavor profiles and consumer acceptability.


Asunto(s)
Pan/análisis , Ácidos Grasos Insaturados/metabolismo , Espectrometría de Masas en Tándem , Triticum/química , Agentes Aversivos/análisis , Cromatografía Líquida de Alta Presión , Ácidos Grasos Insaturados/análisis , Harina/análisis , Humanos , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal , Umbral Gustativo , Triticum/metabolismo
14.
Food Funct ; 12(5): 1983-1995, 2021 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-33537688

RESUMEN

To evaluate the effect of young apple polyphenols (YAP) on starch digestion and gut microbiota, complexes of native wheat starch (NWS) with YAP, and their main components chlorogenic acid (CA) and phlorizin (P) were fabricated and gelatinized. Through XRD and FTIR analysis, it was found that the partial crystalline structure of NWS was destroyed during gelatinization, and the addition of P decreased the extent of destruction. Then, the gelatinized starchy samples were subjected to in vitro digestion. The wheat starch (WS)-phenolic compound complexes significantly suppressed the digestion rate and increased the proportion of resistant starch (RS) in WS. Furthermore, the residual starchy components after digestion were fermented by human fecal samples for 24 h. The WS-YAP complex greatly increased the concentration of short-chain fatty acids (SCFAs), especially acetic and propionic acids, and enhanced the growth of health-promoting gut microbiota such as Prevotella. Conclusively, YAP was shown to play a positive role in maintaining blood glucose balance and intestinal health.


Asunto(s)
Digestión/efectos de los fármacos , Fermentación/efectos de los fármacos , Malus/química , Polifenoles/farmacología , Almidón/metabolismo , Triticum/química , Adulto , Bacterias/clasificación , Bacterias/metabolismo , Cristalización , Ácidos Grasos/metabolismo , Ácidos Grasos Volátiles/metabolismo , Heces/microbiología , Frutas/química , Gelatina/química , Humanos , Almidón/química , alfa-Amilasas/metabolismo
15.
J Chromatogr A ; 1639: 461930, 2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33556780

RESUMEN

Herein, a facile and practical aptamer-grafted ionic affinity monolith with mixed-mode mechanism was explored as a versatile platform for online specific recognition of polar and non-polar mycotoxins. The mixed-mode mechanism including molecular affinity adsorption (between aptamers and targets), hydrophilic interaction and ionic interaction (between stationary phase and targets) were adopted and provided a better flexibility in adjusting separation selectivity to reduce nonspecific adsorption with respect to the single mode. Preparation and characterization of aptamer-based affinity monoliths were investigated, The characterization of pore size distribution, Brunauer-Emmett-Teller (BET) surface area and the specificity and cross-reaction were also evaluated. As a result, the hydrophilic nature and negative charge on affinity monolith were obtained. Multiple interactions including aptamer affinity binding, hydrophilic interaction (HI) and ion exchange (IE) could be adopted for online selective extraction. Specific recognitions of polar ochratoxin A (OTA), non-polar zearalenone (ZEN) and aflatoxin B1 (AFB1) was fulfilled with LODs as 0.03, 0.05 and 0.05 µg/L, respectively. Applied to real cereals, good recoveries of the fortified OTA, AFB1 and ZEN were achieved as 92.6 ± 1.3% ~ 95.6 ± 1.3% (n=3), 93.9 ± 2.3% ~ 98.2 ± 3.4% (n=3) and 92.7 ± 2.0% ~ 96.9 ± 3.5% (n=3) in corn, wheat and rice, respectively. The results displayed that Apt-MCs with hydrophilic and ionic interaction mixed-mode mechanism were efficient enough and competent for the online recognition of mycotoxins in cereals.


Asunto(s)
Aptámeros de Nucleótidos/química , Micotoxinas/análisis , Sistemas en Línea , Acetonitrilos/química , Aflatoxina B1/análisis , Calibración , Cromatografía Líquida de Alta Presión , Grano Comestible/química , Interacciones Hidrofóbicas e Hidrofílicas , Iones , Límite de Detección , Ocratoxinas/análisis , Oryza/química , Reproducibilidad de los Resultados , Triticum/química , Zea mays/química , Zearalenona/análisis
16.
Food Chem ; 349: 129167, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33567351

RESUMEN

Faba bean (Vicia faba L.) flour, starch concentrate (60% starch), protein concentrate (~60% protein) and protein isolate (~85% protein) were added to replace one-quarter of durum wheat semolina to enrich the nutritional quality and physiological functions of durum wheat (Triticum turgidum L.) pasta. The raw pasta samples prepared with protein concentrate or isolate had higher (p ≤ 0.001) protein and lower (p ≤ 0.001) total starch concentrations, along with increased total dietary fiber and slowly digestible starch (p ≤ 0.001) than durum wheat semolina control or those with added whole faba-bean flour or isolated starch. The faba bean fortified pasta had altered starch with increased proportion of medium B-type glucan chains and long C-type glucan chains, reduced starch digestibility and were associated with glycaemia related effects in the human diet. The faba bean fortified pasta had increased protein and dietary fiber that influenced food intake and satiety. The results suggest differential contributions of food ingredients in human health outcomes.


Asunto(s)
Alimentos Fortificados , Triticum/química , Vicia faba/química , Glucemia/metabolismo , Fibras de la Dieta/metabolismo , Suplementos Dietéticos , Harina , Humanos , Comidas , Valor Nutritivo , Almidón/química
17.
Int J Biol Macromol ; 171: 331-342, 2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33422512

RESUMEN

Two methods, HCl and enzymatic treatments, were evaluated for diversification of morphological and functional properties of cellulose nanofibers (CNF) from two- stage-alkaline pre-treated wheat straw (WS). The extraction conditions were optimized by a central composite designed experimental approach varying time (4-8 h) and temperature (80-120 °C) for the HCl-based treatment and time (4-8 h), and FiberCare dosage (50-100 endo-1,4-ß-glucanase unit/g) and Viscozyme (10-20 fungal ß-glucanase units/g) for the enzyme-based treatment. The CNF yields, morphological (polydispersity index (PdI), length and diameter), and functional (crystallinity and thermal degradation) properties were compared. The CNF produced by the HCl (HCN) and enzymatically (ECN) attained diameters ~17 nm had PdI, length, and crystallinity of 0.53, 514 nm & 70%, and 0.92, 1.0 µm & 48%, respectively. Thus, the HCN morphology suits homogenous nano-applications, whereas that of the ECN, would suit heterogenous nano-applications. The HCN and ECN yields were similar (~20%) with optimal production time of 7.41 and 4.64 h, respectively. Both the HCN & ECN can be classified as thermally stable nanocolloids with maximum thermal degradation temperatures of ~380 °C and Zeta potential ~-16 mV. The two CNF production methods have potential synergetic effects on CNF production, morphological, and functional properties.


Asunto(s)
Celulosa/aislamiento & purificación , Nanofibras/química , Celulasas/farmacología , Celulosa/química , Coloides/química , Cristalización , Proteínas Fúngicas/farmacología , Glicósido Hidrolasas/farmacología , Calor , Ácido Clorhídrico/farmacología , Complejos Multienzimáticos/farmacología , Tallos de la Planta/química , Tallos de la Planta/efectos de los fármacos , Electricidad Estática , Triticum/química
18.
Int J Biol Macromol ; 173: 26-33, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33422515

RESUMEN

The protein vital gluten is mainly used for food while interest for non-food applications, like biodegradable materials, increases. In general, the structure and functionality of proteins is highly dependent on thermal treatments during production or modification. This study presents conformational changes and corresponding rheological effects of vital wheat gluten depending on temperature. Dry samples analyzed by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermalgravimetric analysis coupled with mass spectrometry (TGA-MS) show surface compositions and conformational changes from 25 to 250 °C. Above 170 °C, XPS reveals a decreased N content at the surface while FTIR band characteristics for ß-sheets prove structural changes. At 250 °C, protein denaturation accompanied by a significant mass loss due to dehydration and decarbonylation reactions is observed. Oscillatory measurements of optimally hydrated vital gluten describing network properties of the material show two structural changes along a temperature ramp from 25 to 90 °C: at 56-64 °C, the temperature necessary to trigger structural changes increases with the ratio of gliadin to total protein mass, determined by reversed-phase high performance liquid chromatography (RP-HPLC). At a temperature of 79-81 °C, complete protein denaturation occurs. FTIR confirms the denaturation process by showing band shifts with both temperature steps.


Asunto(s)
Gliadina/química , Glútenes/química , Agua/química , Calor , Interacciones Hidrofóbicas e Hidrofílicas , Espectroscopía de Fotoelectrones , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Desnaturalización Proteica , Reología , Espectroscopía Infrarroja por Transformada de Fourier , Triticum/química
19.
Carbohydr Polym ; 256: 117518, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483039

RESUMEN

This study aims to understand the starch molecular structural changes from baking sugar-snap cookies. Changes in the whole-molecule size distribution and chain-length distribution of the parent wheat flour and from final cookie products were measured by size-exclusion chromatography with and without enzymatic debranching, and the results fitted by two biosynthesis-based models. Fraction crystallinity was also analyzed. After cooking, there was a significant decrease in average molecular sizes of amylopectin and in the average lengths of amylose chains, and some starch granules lost birefringence. However, the chain-length distributions of amylopectin showed no noticeable difference, resulting in little change in relative crystallinity and gelatinization temperatures. Both the short-range ordered structure and the periodic lamellar structure were disrupted. This study provides new insight into starch structural changes in sugar-snap cookies after baking, which play an important role in determining final cookie quality. For example, a decrease in size of amylose chains influences cookie sensory properties, and thus can be used as an additional tool for choice of grains.


Asunto(s)
Amilopectina/química , Amilosa/química , Harina/análisis , Azúcares/química , Triticum/química , Birrefringencia , Culinaria/métodos , Cristalización , Humanos , Estructura Molecular
20.
J Agric Food Chem ; 69(5): 1656-1666, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33501830

RESUMEN

It is commonly known that the widespread use of antibiotics has led to their existence in food products as residues and ingestion of these food products may create a selection pressure on bacteria inhabiting the human body. In this study, an optimized method for the analysis of antibiotic residues in different food groups, including cereals, meat, eggs, milk, vegetables, and fruits, was developed using solvent extraction, solid-phase extraction cleanup, and liquid chromatography-mass spectrometry (LC-MS/MS). The limits of detection (LODs) were achieved as 0.007-1.1, 0.008-0.46, 0.002-0.67, 0.007-0.63, 0.001-0.098, and 0.005-0.26 ng/g in ng/g in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The overall average recoveries at three spiking levels of the 81 antibiotics (5, 25, and 50 ng/g dry weight) were 82 ± 26, 77 ± 26, 70 ± 34, 69 ± 31, 73 ± 29, and 62 ± 37% in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The method was then applied to the analysis of the targets in the collected wheat flour, mutton, chicken egg, boxed milk, cabbage, and banana samples, with the total concentration of the antibiotics detected being 4.4, 2.3, 36, 5.5, 2.7, and 14 ng/g, respectively. This work suggests that the developed method provides a time- and cost-effective method to identify and quantify antibiotic residues in common food products.


Asunto(s)
Antibacterianos/química , Cromatografía Líquida de Alta Presión/métodos , Residuos de Medicamentos/química , Contaminación de Alimentos/análisis , Espectrometría de Masas en Tándem/métodos , Animales , Antibacterianos/aislamiento & purificación , Bovinos , Pollos , Residuos de Medicamentos/aislamiento & purificación , Huevos/análisis , Harina/análisis , Frutas/química , Límite de Detección , Carne/análisis , Leche/química , Extracción en Fase Sólida , Triticum/química , Verduras/química
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