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1.
Molecules ; 29(12)2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38930947

RESUMEN

Starch is a natural plant raw material applicable in many areas of industry. In practice, it is most often used in a modified form, i.e., after various treatments aimed at modifying its properties. Modifications of native starch enable producing resistant starch, which, as a prebiotic with confirmed health-promoting properties, has been increasingly used as a food additive. The present study aimed to determine the effect of roasting retrograded starch with the addition of anhydrous glucose at different temperatures (110, 130 or 150 °C) and different times (5 or 24 h) on the modified starch's properties. The results of high-performance size-exclusion chromatography coupled with refractive index detector (HPSEC/RI) analysis and the changes observed in the solubility of starch roasted with glucose in DMSO, as well as in its other properties, confirm the changes in its molecular structure, including thermolytic degradation and the ongoing polymerization of starch with added glucose.


Asunto(s)
Glucosa , Almidón , Glucosa/química , Almidón/química , Solubilidad , Calor , Almidón Resistente , Culinaria , Temperatura
2.
Int J Mol Sci ; 25(12)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38928007

RESUMEN

Three types of starch with different amylose content were esterified and blended with polybutylene succinate (PBS) to obtain esterified manioc starch/PBS (EMS/PBS), esterified corn starch/PBS (ECS/PBS), and esterified waxy corn starch/PBS (EWS/PBS) composites. The EMS/PBS and ECS/PBS composites with high amylose content displayed typical V-type crystal structures. The original crystals of EWS, which had low amylose content, were disrupted during the esterification process. EWS exhibited the strongest interaction with PBS and the most favorable interface compatibility. The pyrolysis temperature was in order of EMS/PBS < ECS/PBS < EWS/PBS. The elongation at break of the three blends was higher than that of pure PBS. The esterification and plasticization of the EWS/PBS composite were the most comprehensive. The EWS/PBS composite showed the lowest storage modulus (G') and complex viscosity (η*). The interfacial bonding force of the composite materials increased with more amylopectin, decreasing intermolecular forces and destroying crystal structures, which decreased G' and η* and increased toughness. The EWS/PBS composite, with the least amylose content, had the best hydrophobicity and degradation performance.


Asunto(s)
Amilosa , Amilosa/química , Esterificación , Almidón/química , Polímeros/química , Viscosidad , Polienos/química , Zea mays/química , Butileno Glicoles/química
3.
Sci Rep ; 14(1): 12682, 2024 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-38830978

RESUMEN

In the field of biotechnology, the utilization of agro-industrial waste for generating high-value products, such as microbial biomass and enzymes, holds significant importance. This study aimed to produce recombinant α-amylase from Anoxybacillus karvacharensis strain K1, utilizing whey as an useful growth medium. The purified hexahistidine-tagged α-amylase exhibited remarkable homogeneity, boasting a specific activity of 1069.2 U mg-1. The enzyme displayed its peak activity at 55 °C and pH 6.5, retaining approximately 70% of its activity even after 3 h of incubation at 55 °C. Its molecular weight, as determined via SDS-PAGE, was approximately 69 kDa. The α-amylase demonstrated high activity against wheat starch (1648.8 ± 16.8 U mg-1) while exhibiting comparatively lower activity towards cyclodextrins and amylose (≤ 200.2 ± 16.2 U mg-1). It exhibited exceptional tolerance to salt, withstanding concentrations of up to 2.5 M. Interestingly, metal ions and detergents such as sodium dodecyl sulfate (SDS), Triton 100, Triton 40, and Tween 80, 5,5'-dithio-bis-[2-nitrobenzoic acid (DNTB), ß-mercaptoethanol (ME), and dithiothreitol (DTT) had no significant inhibitory effect on the enzyme's activity, and the presence of CaCl2 (2 mM) even led to a slight activation of the recombinant enzyme (1.4 times). The Michaelis constant (Km) and maximum reaction rate (Vmax), were determined using soluble starch as a substrate, yielding values of 1.2 ± 0.19 mg mL-1 and 1580.3 ± 183.7 µmol mg-1 protein min-1, respectively. Notably, the most favorable conditions for biomass and recombinant α-amylase production were achieved through the treatment of acid whey with ß-glucosidase for 24 h.


Asunto(s)
Anoxybacillus , Detergentes , Suero Lácteo , alfa-Amilasas , alfa-Amilasas/metabolismo , alfa-Amilasas/química , Suero Lácteo/metabolismo , Suero Lácteo/química , Anoxybacillus/enzimología , Anoxybacillus/genética , Detergentes/química , Concentración de Iones de Hidrógeno , Estabilidad de Enzimas , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Almidón/metabolismo , Almidón/química , Temperatura
4.
Food Res Int ; 189: 114563, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38876595

RESUMEN

The digestibility of ungelatinized, short-term retrograded and long-term retrograded starch from foxtail millet was investigated and correlated with starch chain length distributions (CLDs). Some variations in starch CLDs of different varieties were obtained. Huangjingu and Zhonggu 9 had higher average chain lengths of debranched starch and lower average chain length ratios of amylopectin and amylose than Dajinmiao and Jigu 168. Compared to ungelatinized starch, retrogradation significantly increased the estimated glycemic index (eGI), whereas significantly decreased the resistant starch (RS). In contrast, long-term retrograded starches have lower eGI (93.33-97.37) and higher RS (8.04-14.55%) than short-term retrograded starch. PCA and correlation analysis showed that amylopectin with higher amounts of long chains and longer long chains contributed to reduced digestibility in ungelatinized starch. Both amylose and amylopectin CLDs were important for the digestibility of retrograded starch. This study helps a better understanding of the interaction of starch CLDs and digestibility during retrogradation.


Asunto(s)
Amilopectina , Amilosa , Digestión , Setaria (Planta) , Almidón , Setaria (Planta)/química , Setaria (Planta)/metabolismo , Almidón/química , Almidón/metabolismo , Amilopectina/química , Amilosa/química , Índice Glucémico
5.
Food Res Int ; 189: 114561, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38876594

RESUMEN

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.


Asunto(s)
Geles , Polisacáridos , Reología , Almidón , Vigna , Almidón/química , Polisacáridos/química , Espectroscopía Infrarroja por Transformada de Fourier , Vigna/química , Difracción de Rayos X , Microscopía Electrónica de Rastreo , Interacciones Hidrofóbicas e Hidrofílicas , Agua/química , Enlace de Hidrógeno
6.
Carbohydr Polym ; 341: 122321, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38876723

RESUMEN

Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.


Asunto(s)
Antibacterianos , Biopelículas , Almidón , Taninos , Resistencia a la Tracción , Almidón/química , Taninos/química , Taninos/farmacología , Biopelículas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Antiinfecciosos/farmacología , Antiinfecciosos/química , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Polifenoles
7.
Int J Biol Macromol ; 272(Pt 1): 132779, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38825268

RESUMEN

The effects of high-resistant starch (RS) content rice flour, psyllium husk powder (PHP), and psyllium powder (PP) on the edible quality and starch digestibility of rice noodles were investigated in this study. High-RS rice noodles showed lower digestibility but poor edible quality. With the addition of PHP and PP, high-RS rice noodles' cooking and texture quality were improved significantly, especially the breakage rates, cooking losses, and chewiness (P < 0.05). Compared to traditional white rice noodle's estimated glycemic index (eGI) of 86.69, the eGI values for 5PHP-RN and 5PHP-2PP-RN were significantly decreased to 66.74 and 65.77, achieving a medium GI status (P < 0.05). This resulted from the high amylose and lipid content in the modified rice flour and psyllium, leading to increase of starch crystallinity. Besides, based on the analysis of Pearson's correlation, it can be found that PHP rich in insoluble dietary fiber (IDF) could improve high-RS noodle cooking and texture quality better, while PP rich in soluble dietary fiber (SDF) can further reduce the RDS content and its starch digestibility. Therefore, utilizing modified rice flour with an appropriate addition of PHP and PP can be considered an effective strategy for producing superior-quality lower glycemic index rice noodles.


Asunto(s)
Fibras de la Dieta , Harina , Oryza , Psyllium , Almidón , Oryza/química , Psyllium/química , Harina/análisis , Almidón/química , Fibras de la Dieta/análisis , Índice Glucémico , Culinaria/métodos , Amilosa/análisis , Amilosa/química , Almidón Resistente/análisis
8.
Molecules ; 29(11)2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38893498

RESUMEN

Due to the high content of impurities such as proteins in tamarind seed polysaccharide (TSP), they must be separated and purified before it can be used. TSP can disperse in cold water, but a solution can only be obtained by heating the mixture. Therefore, it is important to understand the dispersion and dissolution process of TSP at different temperatures to expand the application of TSP. In this study, pasting behavior and rheological properties as a function of temperature were characterized in comparison with potato starch (PS), and their relationship with TSP molecular features and microstructure was revealed. Pasting behavior showed that TSP had higher peak viscosity and stronger thermal stability than PS. Rheological properties exhibited that G' and G'' of TSP gradually increased with the increase in temperature, without exhibiting typical starch gelatinization behavior. The crystalline or amorphous structure of TSP and starch was disrupted under different temperature treatment conditions. The SEM results show that TSP particles directly transformed into fragments with the temperature increase, while PS granules first expanded and then broken down into fragments. Therefore, TSP and PS underwent different dispersion mechanisms during the dissolution process: As the temperature gradually increased, TSP possibly underwent a straightforward dispersion and was then dissolved in aqueous solution, while PS granules initially expanded, followed by disintegration and dispersion.


Asunto(s)
Polisacáridos , Reología , Semillas , Almidón , Tamarindus , Temperatura , Tamarindus/química , Polisacáridos/química , Semillas/química , Viscosidad , Almidón/química , Fenómenos Químicos
9.
Molecules ; 29(11)2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38893561

RESUMEN

The application of chemical operations in food processing, in which pure chemical compounds are used to modify food ingredients, often raises social concerns. One of the most frequently modified dietary substances is starch, e.g., E1401-E1404, E1412-E1414, E1420, E1422, E1440, E1442, and E1450-E1452. An alternative solution to chemical treatments seems to be the use of raw materials naturally containing substrates applied for starch modification. Heating starch with a lemon juice concentrate can be considered a novel and effective method for producing starch citrate, which is part of the so-called "green chemistry". The modified preparations obtained as a result of potato starch esterification with natural lemon juice had a comparable degree of esterification to that of the esters produced with pure citric acid. In addition, the use of the juice doubled their resistance to amylolytic enzymes compared to the preparations made with pure acid. Replacing citric acid with lemon juice can facilitate the esterification process, and the analyzed properties of both types of modified preparations indicate that starch esters produced with pure citric acid can be successfully replaced by those produced using natural lemon juice, which may increase the social acceptance of these modified preparations.


Asunto(s)
Ácido Cítrico , Citrus , Jugos de Frutas y Vegetales , Solanum tuberosum , Almidón , Esterificación , Ácido Cítrico/química , Almidón/química , Citrus/química , Jugos de Frutas y Vegetales/análisis , Solanum tuberosum/química , Manipulación de Alimentos/métodos
10.
ACS Appl Mater Interfaces ; 16(24): 30742-30754, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38841831

RESUMEN

Uncontrolled hemorrhage and infection are the principal causes of mortality associated with trauma in both military and civilian medical settings. Modified starch granules have emerged as a safe hemostatic agent for irregular and noncompressible wounds, but their performance is constrained by limited hemostasis efficiency and modest antibacterial activity. This study reported a directed self-assembly approach for a multifunctional mesoporous starch-based microparticle loaded with chitosan and calcium ions (Ca@MSMP) used for rapid hemostasis and wound healing. Directed self-assembly of uniform Ca@MSMP with a hierarchical hollow structure in the presence of chitosan was confirmed by scanning electron microscopy (SEM) analysis and pore structure analysis. The resulting Ca@MSMP exhibited a well-defined spherical shape and uniform size of 1 µm and demonstrated excellent antibacterial activity (>95%) without hemolytic activity. Importantly, Ca@MSMP enhanced blood coagulation and platelet aggregation via the synergistic effect of rapid calcium release and chitosan-mediated electrostatic interactions, leading to a significant decrease in blood loss and reduction in hemostasis time in rat tail amputation and liver injury models. In comparative analyses, Ca@MSMP significantly outperformed the commercial hemostatic agent Quickclean, notably enhancing the healing of full-thickness skin wounds in vivo by effectively preventing infection. These results underscore the potential of this innovative hemostatic material in diverse clinical scenarios, offering effective solutions for the management of bleeding in wounds that are irregularly shaped and noncompressible.


Asunto(s)
Quitosano , Hemostasis , Hemostáticos , Almidón , Cicatrización de Heridas , Animales , Almidón/química , Almidón/farmacología , Cicatrización de Heridas/efectos de los fármacos , Ratas , Hemostáticos/química , Hemostáticos/farmacología , Hemostasis/efectos de los fármacos , Quitosano/química , Quitosano/farmacología , Porosidad , Ratas Sprague-Dawley , Calcio/química , Antibacterianos/farmacología , Antibacterianos/química , Coagulación Sanguínea/efectos de los fármacos , Masculino , Hemorragia/tratamiento farmacológico , Humanos , Staphylococcus aureus/efectos de los fármacos
11.
Food Res Int ; 189: 114533, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38876603

RESUMEN

Glutinous rice is extensively consumed due to its nutritious content and wonderful flavor. However, glutinous rice flour has a high glycemic index, and the storage deterioration of sweet dumplingsissevere. Transglutaminase (TG) was used to cross-link glutinous rice protein and improve the characteristics of glutinous rice products. The findings demonstrated that TG significantly catalysed protein cross-linking to form a dense protein network, reduced the viscosity of glutinous rice paste and improved the thermal stability. The protein network may physically block the access of starch granules to digestive enzymes to lower the digestion rate of starch, and attenuate the damage of ice crystal molecules to the starch structure to improve the freezing stability of starch gels. The cracking rate and water loss of sweet dumplings prepared using glutinous rice flour with TG treated for 60 min reduced significantly. In conclusion, this study broadened the application of TG in starch products.


Asunto(s)
Digestión , Harina , Manipulación de Alimentos , Oryza , Almidón , Transglutaminasas , Oryza/química , Transglutaminasas/metabolismo , Almidón/metabolismo , Almidón/química , Harina/análisis , Manipulación de Alimentos/métodos , Viscosidad , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química
12.
J Environ Manage ; 364: 121323, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38889645

RESUMEN

Herein, the novel double Z-scheme Ag-Ag3O4/CuO-CuFe2O4 magnetic nanophotocatalyst with nanosphere-on-nanosheet-like morphology was synthesized via the corona-plasma-assisted starch-templated microwave-combustion-precipitation method to remove the dye pollutants. The CuO-CuFe2O4 meso/macroporous nanophotocatalyst was synthesized using a one-pot-stage combustion-microwave process with/without starch as a hard-template. Subsequently, surface modification was carried out by DC corona-plasma discharge technology at various voltages, namely 500, 1000 and 1500 V. Then, the Ag3O4 photocatalyst was deposited on the CuO-CuFe2O4 fabricated with starch-hard-template and treated with 1000 V corona-plasma (denoted as: Ag-Ag3O4/CuO-CuFe2O4 (Starch) 1000 P). The properties of the synthesized nanophotocatalysts were analyzed using various techniques, including X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller and Barrett-Joyner-Halenda (BET-BJH), Vibrating Sample Manetometer (VSM), and Photoluminescence (PL). The XRD analysis corroborated the presence of CuO, CuFe2O4 and Ag3O4 in the structure of all samples. The BET-BJH analysis indicates that the specific surface area of the Ag-Ag3O4/CuO-CuFe2O4 (Starch) 1000 P nanophotocatalyst as the best sample is 2 m2/g, higher than other samples. Additionally, the DRS analysis revealed that the band gap of the Ag-Ag3O4/CuO-CuFe2O4 (Starch) 1000 P nanophotocatalyst is about 1.68 eV with the surface plasmon resonance. The performance of the ternary heterostructured Ag-Ag3O4/CuO-CuFe2O4 (Starch) 1000 P nanophotocatalyst was 96.2% and 89.1% in the degradation of the crystal violet (10 mg/L) and acid orange 7 (10 mg/L), respectively, proving its outstanding degradation capacity.


Asunto(s)
Colorantes , Microondas , Almidón , Colorantes/química , Catálisis , Almidón/química , Plata/química , Cobre/química , Difracción de Rayos X , Gases em Plasma/química
13.
PLoS One ; 19(6): e0303964, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38843222

RESUMEN

A Pickering emulsion was synergistically stabilised with zein nanoparticles (ZNPs) and starch nanocrystals (SNCs) to prepare it for menthol loading. After response surface optimisation of the emulsion preparation conditions, a Pickering emulsion prepared with a ZNPs:SNCs ratio of 1:1, a particle concentration of 2 wt% and a water:oil ratio of 1:1 provided the highest menthol encapsulation rate of the emulsions tested (83%) with good storage stability within 30 days. We examined the bilayer interface structure of the emulsion by optical microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The results of simulated digestion experiments showed that the release rate of free fatty acid was 75.06 ± 1.23%, which ensured bioavailability. At the same time, the emulsions facilitated the slow release of menthol. Bacteriostatic studies revealed that the Pickering emulsion had a protective effect on menthol, with the most significant inhibitory effects on Escherichia coli and Staphylococcus aureus under the same conditions. Overall, this study proposes a novel approach for the application and development of l-menthol by combining it with Pickering emulsion.


Asunto(s)
Emulsiones , Escherichia coli , Mentol , Nanopartículas , Staphylococcus aureus , Almidón , Zeína , Mentol/química , Mentol/farmacología , Emulsiones/química , Nanopartículas/química , Zeína/química , Almidón/química , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Tamaño de la Partícula
14.
Carbohydr Polym ; 340: 122273, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38858001

RESUMEN

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.


Asunto(s)
Almidón , Almidón/química , Rastreo Diferencial de Calorimetría , Tamaño de la Partícula , Manipulación de Alimentos/métodos , Peso Molecular
15.
Carbohydr Polym ; 340: 122217, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38857997

RESUMEN

Iodine (I2) as a broad-spectrum antiseptic has been widely used for treating bacterial infections. However, I2 has low water-solubility and sublimes under ambient conditions, which limits its practical antibacterial applications. The highly specific and sensitive reaction between I2 and starch discovered 200 years ago has been extensively applied in analytical chemistry, but the antibacterial activity of the I2-starch complex is rarely investigated. Herein, we develop a novel type of iodine-based antiseptics, iodine-soluble starch (I2-SS) cryogel, which can dissolve in water instantly and almost completely kill bacteria in 10 min at 2 µg/mL of I2. Although KI3 and the commercially available povidone­iodine (I2-PVP) solutions show similar antibacterial efficacy, the high affinity of I2 to SS largely enhances the shelf stability of the I2-SS solution with ∼73 % I2 left after one-week storage at room temperature. In sharp contrast, ∼8.5 % and âˆ¼2.5 % I2 are detected in KI3 and I2-PVP solutions, respectively. Mechanistic study reveals that the potent antibacterial effect of I2-SS originates from its attack on multiple bacterial targets. The outstanding antibacterial activity, capability of accelerating wound healing, and good biocompatibility of I2-SS are verified through further in vivo experiments. This work may promote the development of next-generation iodine-based antiseptics for clinical use.


Asunto(s)
Antibacterianos , Antiinfecciosos Locales , Criogeles , Yodo , Solubilidad , Almidón , Agua , Yodo/química , Yodo/farmacología , Almidón/química , Almidón/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Antiinfecciosos Locales/farmacología , Antiinfecciosos Locales/química , Agua/química , Criogeles/química , Animales , Staphylococcus aureus/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana , Povidona Yodada/química , Povidona Yodada/farmacología , Escherichia coli/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos
16.
Carbohydr Polym ; 340: 122249, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38858018

RESUMEN

The recently characterized Limosilactobacillus reuteri N1 GtfB (LrN1 GtfB) from glycoside hydrolase family 70 is a novel 4,6-α-glucanotransferase acting on starch/maltooligosaccharides with high enzyme activity and soluble protein yield (in heterogenous system). In this study, the influence of the treatment by LrN1 GtfB on the fine structure and functional characteristics of three maize starches were furtherly investigated and elucidated. Due to the treatment of LrN1 GtfB, the starch molecules were transformed into reuterans containing linear and branched (α1 â†’ 6) linkages with notably smaller molecular weight and shorter chain length. Moreover, the (α1 â†’ 6) linkage ratios in the GtfB-modified high-amylose maize starch (GHMS)/normal maize starch (GNMS)/waxy maize starch (GWMS) increased by 18.3 %/12.6 %/9.0 % as compared to their corresponding controls. In vitro digestibility experiment revealed that the resistant starch content of GHMS, GNMS and GWMS increased by 16 %, 18 % and 25 % as compared to the starch substrates. Furthermore, the butyric acid yielded from GHMS, GNMS and GWMS in the in vitro fermentation experiments were 1.4, 1.5 and 1.4 times higher than those of commercial galactose oligosaccharides. These results indicated that the highly-branched short-clustered reuteran synthesized by LrN1 GtfB might serve as novel potential prebiotics, and provide insights for the synthesis of promising prebiotic dietary fiber from starch.


Asunto(s)
Limosilactobacillus reuteri , Prebióticos , Almidón , Zea mays , Zea mays/química , Almidón/química , Almidón/metabolismo , Oligosacáridos/química
17.
Carbohydr Polym ; 340: 122319, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38858013

RESUMEN

The survival rate of mesenchymal stem cells (MSC), a crucial factor in tissue engineering, is highly dependent on glucose supply. The purpose of this paper is to study the potential of starch foams as glucose suppliers. It is investigated through in vitro hydrolysis by amyloglucosidase in conditions that respect physiological constraints (37 °C and pH 7.4), including a duration of 21 days, and no stirring. Nine extruded starch foams with amylose contents ranging from 0 to 74 %, with various cell wall thicknesses (50 to 300 µm), and different crystallinities (0-30 %) were hydrolysed. These kinetics were fitted by a model which shows that the maximum rate of hydrolysis varies from 7 to 100 %, and which allows the rate of hydrolysis at 21 days to be calculated precisely. The results reveal the major role of amylose in glucose delivery kinetics, and the secondary roles of crystallinity and cell wall thickness of the foams. Additional hydrolysis of starch films revealed that thickness positively influences the amylose chain reorganisation during hydrolysis, which, in slows down and limits glucose delivery. A simple glucose delivery kinetics analysis procedure is proposed to select samples for testing as MSC glucose suppliers.


Asunto(s)
Amilosa , Materiales Biocompatibles , Glucosa , Células Madre Mesenquimatosas , Almidón , Hidrólisis , Glucosa/química , Almidón/química , Materiales Biocompatibles/química , Amilosa/química , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Cinética , Glucano 1,4-alfa-Glucosidasa/metabolismo , Glucano 1,4-alfa-Glucosidasa/química
18.
Carbohydr Polym ; 340: 122303, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38858024

RESUMEN

The objective of this work was to study the effects of heat-moisture treatment (HMT) of freshly harvested mature high-amylose maize (HAM) kernels on its starch structure, properties, and digestibility. Freshly harvested HAM kernels were sealed in Pyrex glass bottles and treated at 80 °C, 100 °C, or 120 °C. HMT of HAM kernels had no impact on its starch X-ray diffraction pattern but increased the relative crystallinity. This result together with the increased starch gelatinization temperatures and enthalpy change indicated starch molecules reorganization forming long-chain double-helical crystalline structure during HMT of HAM kernels. The aggregation of starch granules were observed after HMT, indicating interaction of starch granules and other components. This interaction and the high-temperature crystalline structure led to reductions in the starch digestibility, swelling power, solubility, and pasting viscosity of the HAM flours. Some starch granules remained intact and showed strong birefringence after the HAM flours were precooked at 100 °C for 20 min and followed by enzymatic hydrolysis, and the amount of undigested starch granules increased with increasing HMT temperatures. This result further supported that HMT of HAM kernels with high moisture level could increase the starch thermal stability and enzymatic resistance.


Asunto(s)
Amilosa , Calor , Almidón , Zea mays , Zea mays/química , Amilosa/química , Almidón/química , Hidrólisis , Viscosidad , Solubilidad , Agua/química , Difracción de Rayos X , Harina/análisis
19.
Molecules ; 29(12)2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38930854

RESUMEN

Glycogen, an α-glucan polymer serving as an energy storage compound in microorganisms, is synthesized through distinct pathways (GlgC-GlgA or GlgE pathway). Both pathways involve multiple enzymes, with a shared glycogen branching enzyme (GBE). GBEs play a pivotal role in establishing α-1,6-linkages within the glycogen structure. GBEs are also used for starch modification. Understanding how these enzymes work is interesting for both glycogen synthesis in microorganisms, as well as novel applications for starch modification. This study focuses on a putative enzyme GH13_9 GBE (PoGBE13), present in a polysaccharide utilization locus (PUL) of Pontibacter sp. SGAir0037, and related to the GlgE glycogen synthesis pathway. While the PUL of Pontibacter sp. SGAir0037 contains glycogen-degrading enzymes, the branching enzyme (PoGBE13) was also found due to genetic closeness. Characterization revealed that PoGBE13 functions as a typical branching enzyme, exhibiting a relatively high branching over non-branching (hydrolysis and α-1,4-transferase activity) ratio on linear maltooctadecaose (3.0 ± 0.4). Besides the GH13_9 GBE, a GH57 (PoGH57) enzyme was selected for characterization from the same PUL due to its undefined function. The combined action of both GH13 and GH57 enzymes suggested 4-α-glucanotransferase activity for PoGH57. The characterization of these unique enzymes related to a GlgE glycogen synthesis pathway provides a more profound understanding of their interactions and synergistic roles in glycogen synthesis and are potential enzymes for use in starch modification processes. Due to the structural similarity between glycogen and starch, PoGBE13 can potentially be used for starch modification with different applications, for example, in functional food ingredients.


Asunto(s)
Glicósido Hidrolasas , Glicósido Hidrolasas/metabolismo , Glicósido Hidrolasas/genética , Glucógeno/metabolismo , Glucógeno/biosíntesis , Polisacáridos/metabolismo , Polisacáridos/química , Polisacáridos/biosíntesis , Enzima Ramificadora de 1,4-alfa-Glucano/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucano/genética , Almidón/metabolismo , Almidón/química , Especificidad por Sustrato , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/química
20.
Food Chem ; 454: 139853, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38823200

RESUMEN

The effects of SHP on the texture, rheological properties, starch crystallinity and microstructure of frozen dough were investigated. The efficacy of SHP in enhancing dough quality is concentration-dependent, with frozen dough containing 1.5% SHP exhibiting hardness comparable to fresh dough without SHP (221.31 vs. 221.42 g). Even at 0.5% SHP, there is a noticeable improvement in frozen dough quality. The rheological results showed that the viscoelasticity of dough increased with higher SHP concentration. What's more, XRD and SEM results indicated that the SHP's hydrophilicity reduces the degree of starch hydrolysis, slows down the damage of starch particles during freezing, and consequently lowers the crystallinity of starch. Additionally, CLSM observations revealed that SHP enhances the gluten network structure, diminishing the appearance of holes. Therefore, the physical, chemical properties, and microstructure of frozen dough with SHP demonstrate significant enhancement, suggesting SHP's promising antifreeze properties and potential as a food antifreeze agent.


Asunto(s)
Harina , Congelación , Glycine max , Polisacáridos , Reología , Harina/análisis , Polisacáridos/química , Glycine max/química , Pan/análisis , Viscosidad , Almidón/química
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