Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Opt Lett ; 49(7): 1749-1752, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38560853

RESUMEN

Non-contact optical temperature measurement can effectively avoid the disadvantages of traditional contact thermometry and thus, become a hot research topic. Herein, a fluorescence intensity ratio (FIR) thermometry using a time-resolved technique based on La2CaZrO6:Cr3+ (LCZO) is proposed, with a maximum relative sensitivity (Sr - FIR) of 2.56% K-1 at 473 K and a minimum temperature resolution of 0.099 K. Moreover, the relative sensitivity and temperature resolution can be effectively controlled by adjusting the width of the time gate based on the time-resolved technique. Our work provides, to our knowledge, new viewpoints into the development of novel optical thermometers with adjustable relative sensitivity and temperature resolution on an as-needed basis.

2.
Crit Rev Food Sci Nutr ; : 1-16, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38920118

RESUMEN

As compared with exogenous components, non-starch components (NSCS), such as proteins, lipids, non-starch polysaccharides (NSPs), and polyphenols, inherently present in cereals, are more effective at inhibiting starch digestibility. Existing research has mostly focused on complex systems but overlooked the analysis of the in-situ role of the NSCS. This study reviews the crucial mechanisms by which endogenous NSCS inhibit starch digestion, emphasizing the spatial distribution-function relationship. Starch granules are filled with pores/channels-associated proteins and lipids, embedding in the protein matrix, and maintained by endosperm cell walls. The potential starch digestion inhibition of endogenous NSCS is achieved by altering starch gelatinization, molecular structure, digestive enzyme activity, and accessibility. Starch gelatinization is constrained by endogenous NSCS, particularly cell wall NSPs and matrix proteins. The stability of the starch crystal structure is enhanced by the proteins and lipids distributed in the starch granule pores and channels. Endogenous polyphenols greatly inhibit digestive enzymes and participate in the cross-linking of NSPs in the cell wall space, which together constitute a physical barrier that hinders amylase diffusion. Additionally, the spatial entanglement of NSCS and starch under heat and non-heat processing conditions reduces starch accessibility. This review provides novel evidence for the health benefits of whole cereals.

3.
Crit Rev Food Sci Nutr ; : 1-15, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950560

RESUMEN

In cereals, the protein body and protein matrix are usually two morphological protein structures. However, processing treatments can affect protein structures, change protein bodies into the matrix, or induce a change in the matrix structure; therefore, the processing-induced matrix was listed as the third morphological structure of the protein. Previous research on the effect of proteins was mainly based on protein content and composition, but these studies arrived at different conclusions. Studying the effect of protein morphological structures on sensorial property and starch digestion can provide a theoretical basis for selecting cultivars with high sensorial property and help produce low-glycemic index foods for people with diabetes, controlling their postprandial blood sugar. This study aimed to review the distribution and structure of protein bodies, protein matrices, and processing-induced matrices, as well as their influence on cereal sensorial property and starch digestion. Therefore, we determined the protein morphological structures in different cereal cultivars and summarized its impact. Protein bodies mainly have steric stabilization effects on starch gelatinization, whereas the protein matrix serves as a physical barrier surrounding the starch to inhibit water absorption and α-amylase. Processing can change protein morphological structures, enabling protein bodies to act as a physical matrix barrier.

4.
Opt Express ; 31(16): 25978-25992, 2023 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-37710470

RESUMEN

Although Cr3+ as activator for Near infrared (NIR) phosphors has been widely studied, the peaks of Cr3+ emission spectra in most hosts are less than 1000 nm. Nd3+ as an activator in many hosts has a wide distribution of absorption peaks in the Ultraviolet-visible-Near infrared (UV-vis-NIR) band, especially in the 650-900 nm band for effective NIR to NIR Stokes luminescence (4F3/2→4I9/2, 4F3/2→4I11/2 transitions). Therefore, Cr3+, Nd3+ co-doping to achieve the emission in the NIR II region (1000-1700nm) is very meaningful. Here, we report La2CaZrO6(LCZO): Cr3+, Nd3+ NIR phosphors with emission spectra covering an ultra-wide range of 700-1400 nm and reveal their luminescence mechanism. The energy transfer efficiency of Cr3+ for Nd3+ can be as high as 88.4% under 471 nm blue light excitation. In the same case, the integrated intensity of the emission spectra of Cr3+, Nd3+ co-doped can reach 847% of that of Nd3+ alone and 204% of that of Cr3+ alone. Finally, the combination of commercial blue light chips and Cr3+, Nd3+ co-doped NIR phosphors shows great potential for applications in face recognition, night lighting, and angiography.

5.
J Cell Biochem ; 120(5): 7952-7961, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30456805

RESUMEN

It has been proved that long noncoding RNAs (lncRNAs) are important modulators in the tumorigenesis and progression of various malignant tumors. Recently, lncRNA FOXD2-AS1 has been reported to be an oncogene in several kinds of human cancers. However, the function of FOXD2-AS1 in papillary thyroid cancer (PTC) has not been well investigated. This study aims to explore the biological role and mechanism of FOXD2-AS1 in PTC. At first, the expression of FOXD2-AS1 was examined in PTC tissues and cell lines with quantitative reverse transcription-polymerase chain reaction (qRT-PCR). FOXD2-AS1 was found to observably upregulated in PTC tissues and cell lines. Kaplan-Meier survival analysis revealed that high expression of FOXD2-AS1 was closely correlated with the unfavorable prognosis of patients with PTC. Based on the TCGA data set, KLK7 was overexpressed in PTC tumor samples. Our experimental data further validated the upregulation of KLK7 in PTC tissues and cell lines. Similarly, high level of KLKF was associated with poor prognosis of patients with PTC. The positive expression association between FOXD2-AS1 and KLK7 was analyzed with Pearson correlation coefficient. Loss-of-function assays revealed that knockdown of FOXD2-AS1 or KLK7 greatly inhibited PTC cell proliferation and migration, while induced cell apoptosis. Results of mechanism experiments suggested that FOXD2-AS1 functioned as a competing endogenous RNA (ceRNA) to enhance the expression of KLK7 by sponging miR-485-5p in PTC. Rescue assays were conducted to verify the function of FOXD2-AS1/miR-485-5p/KLK7 axis in PTC progression.

6.
Biochem Biophys Res Commun ; 470(4): 838-44, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26806308

RESUMEN

Dysregulation of microRNA contributes to the high incidence and mortality of breast cancer. Here, we show that miR-625 was frequently down-regulated in breast cancer. Decrease of miR-625 was closely associated with estrogen receptor (P = 0.004), human epidermal growth factor receptor 2 (P = 0.003) and clinical stage (P = 0.001). Kaplan-Meier and multivariate analyses indicated miR-625 as an independent factor for unfavorable prognosis (hazard ratio = 2.654, 95% confident interval: 1.300-5.382, P = 0.007). Re-expression of miR-625 impeded, whereas knockdown of miR-625 enhanced cell viabilities and migration abilities in breast cancer cells. HMGA1 was confirmed as a direct target of miR-625. The expressions of HMGA1 mRNA and protein were induced by miR-625 mimics, but reduced by miR-625 inhibitor. Re-introduction of HMGA1 in cells expressing miR-625 distinctly abrogated miR-625-mediated inhibition of cell growth. Taken together, our data demonstrate that miR-625 suppresses cell proliferation and migration by targeting HMGA1 and suggest miR-625 as a promising prognostic biomarker and a potential therapeutic target for breast cancer.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Proteína HMGA1a/metabolismo , MicroARNs/metabolismo , Adolescente , Adulto , Anciano , Neoplasias de la Mama/patología , Movimiento Celular , Proliferación Celular , China/epidemiología , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Factores de Riesgo , Tasa de Supervivencia , Células Tumorales Cultivadas , Adulto Joven
7.
Mol Biol Rep ; 41(7): 4351-60, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24590739

RESUMEN

Longan (Dimocarpus longan Lour.) is a non-climacteric fruit with a short postharvest life. The regulation of phospholipase D (PLD) activity closely relates to postharvest browning and senescence of longan fruit. In this study, a novel cDNA clone of longan PLDδ (LgPLDδ) was obtained and registered in GenBank (accession No. JF791814). The deduced amino acid sequence possessed all of the three typical domains of plant PLDs, a C2 domain and two catalytic HxKxxxxD motifs. The tertiary structure of LgPLDδ was further predicted. The western blot result showed that the LgPLDδ protein was specifically recognized by PLDδ antibody. The Q-RT-PCR (real-time quantitative PCR) result showed that the level of LgPLDδ mRNA expression was higher in senescent tissues than in developing tissues, which was also high in postharvest fruit. The western-blotting result further certified the different expression of LgPLDδ. These results provided a scientific basis for further investigating the mechanism of postharvest longan fruit adapting to environmental stress.


Asunto(s)
Frutas/genética , Regulación de la Expresión Génica de las Plantas , Fosfolipasa D/genética , Proteínas de Plantas/genética , Sapindaceae/genética , Secuencias de Aminoácidos , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Frutas/enzimología , Regulación del Desarrollo de la Expresión Génica , Datos de Secuencia Molecular , Fosfolipasa D/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sapindaceae/clasificación , Sapindaceae/enzimología , Alineación de Secuencia
8.
BMC Pediatr ; 14: 265, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-25316352

RESUMEN

BACKGROUND: X-linked agammaglobulinemia (XLA) is a rare inherited disease characterized by recurrent bacterial infections, a paucity or absence of peripheral lymphoid tissue, an absence of circulating B cells, and marked depression of serum IgG, IgA, and IgM. Germline mutation of the BTK gene has been identified as a cause of XLA. These mutations cause defects in early B cell development. CASE PRESENTATION: In this study, we report a variant form of XLA with partial B cell function that results from a missense mutation (c.1117C > G) in exon 13 of the BTK gene. A genetic analysis of the family revealed an affected male sibling with a c.1117C > G mutation. He was observed with low level of serum immunoglobulin and CD19+ B cell and received the IVIG replacement therapy regularly in follow up. Four female carriers were found. CONCLUSION: BTK mutation analysis is necessary in the diagnosis of XLA and may be used for subsequent genetic counseling, carrier detection and prenatal diagnosis.


Asunto(s)
Agammaglobulinemia/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Proteínas Tirosina Quinasas/genética , Agammaglobulinemia Tirosina Quinasa , Agammaglobulinemia/terapia , Niño , China , Femenino , Enfermedades Genéticas Ligadas al Cromosoma X/terapia , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Masculino , Mutación Missense , Linaje
9.
Int J Biol Macromol ; : 135513, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39260655

RESUMEN

Physical barriers composed of cell walls and protein matrix in cereals, as well as their cooking changes, play important roles in starch digestion. In this study, the physical barriers of native and cooked highland barley (HB), brown rice (BR), and oats (OA) kernels and their contribution to starch digestion were investigated. The resistant starch content was similar in cereal flours, but varied among cooked kernels (HB > BR > OA: 45.05 %, 10.30 %, and 24.71 %). The water adsorption, gelatinization enthalpy, and decrease in hardness of HB kernels were lower than those of OA and BR kernels. Microstructural observations of native kernels showed that HB had the thickest cell walls. After cooking, the lowest cell wall deformation and a dense continuous network developed from the protein matrix were observed in HB kernels. During digestion, undigested starch granules encapsulated by the stable cell walls and strong protein network were observed in HB kernels, but not in BR or OA kernels. Furthermore, the heavily milled HB kernels still had more resistant starch than the intact OA and BR kernels. Therefore, the physical barriers of HB kernels exhibited stronger inhibition of starch gelatinization and digestion. Differences in cereal physical barriers led to various inhibitory effects.

10.
Food Res Int ; 175: 113618, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38128974

RESUMEN

Summer-autumn tea is characterized by high polyphenol content and low amino acid content, resulting in bitter and astringent teast. However, these qualities often lead to low economic benefits, ultimately resulting in a wastage of tea resources. The study focused on evaluating the effects of foliar spraying of glucosamine selenium (GLN-Se) on summer-autumn tea. This foliar fertilizer was applied to tea leaves to assess its impact on plant development, nutritional quality, elemental uptake, organoleptic quality, and antioxidant responses. The results revealed that GlcN-Se enhanced photosynthesis and yield by improving the antioxidant system. Additionally, the concentration of GlcN-Se positively correlated with the total and organic selenium contents in tea. The foliar application of GlcN-Se reduced toxic heavy metal content and increased the levels of macronutrients and micronutrients, which facilitated adaptation to environmental changes and abiotic stresses. Furthermore, GlcN-Se significantly improved both non-volatile and volatile components of tea leaves, resulting in a sweet aftertaste and nectar aroma in the tea soup. To conclude, the accurate and rational application of exogenous GlcN-Se can effectively enhance the selenium content and biochemical status of tea. This improvement leads to enhanced nutritional quality and sensory characteristics, making it highly significant for the tea industry.


Asunto(s)
Antioxidantes , Selenio , Antioxidantes/metabolismo , Selenio/análisis , Polifenoles , , Valor Nutritivo
11.
Int J Biol Macromol ; 259(Pt 2): 129334, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38218298

RESUMEN

The digestive properties of oat-based food have garnered considerable interest. This study aimed to explore the internal and external factors contributing to different digestion properties of oat flour under actual processing conditions. Analysis of the ordered structure of oat starch revealed that an increase in gelatinization moisture to 60 % led to a decrease in crystallinity, R1047/1022 value, and helical structures content to 0, 0.48 %, and 1.45 %, respectively. Even when the crystal structure was completely destroyed, the short-range structure retained a certain degree of order. Surface structure observations of starch granules and penetration experiments with amylase-sized polysaccharide fluorescence probes indicated that non-starch components and small pores effectively hindered the diffusion of the probes but low-moisture (20 %) gelatinization substantially damaged this barrier. Furthermore, investigations into starch digestibility and starch molecular structure revealed that the ordered structure remaining inside the starch after high gelatinization delayed the digestion rate (0.028 min-1) and did not increase the content of resistant starch (7.10 %). It was concluded that the surface structure and non-starch components of starch granules limited the extent of starch digestion, whereas the spatial barrier of the residual ordered structure affected the starch digestion rate.


Asunto(s)
Avena , Almidón , Almidón/química , Avena/química , Harina , Digestión , Amilasas
12.
Foods ; 12(19)2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37835238

RESUMEN

Cassava flour (CF) was used as a raw material to replace wheat flour (WF) at levels of 0% (control), 10%, 20%, 30%, 40%, and 50% to prepare wheat-cassava composite flour (W-CF) and dough. The effects of different CF substituting levels on the functional properties of the W-CF and dough were investigated. The results show that an increase in CF led to a decrease in the moisture, protein, fat, and b* values of W-CF. The crude fiber, ash, starch, L*, a* values, iodine blue value (IBV), and swelling power (SP) of the composite flour increased gradually. It was found that the water absorption, hardness, and chewiness of the W-CF dough increased with an increase in the CF substitution level. A different trend could be observed with the springiness and cohesiveness of the W-CF dough. The resistance to extension, extensibility, and the extended area of the W-CF dough at all substitution levels was significantly lower than that of the WF dough. The elasticity and cohesiveness of the dough tended to increase for CF content from 10% to 30%, followed by a decrease at a higher replacement. Pearson correlation analysis indicated that the substitution levels of CF had a significant influence on the proximate analysis and functional properties of the W-CF and dough. This study will provide important information on choosing CF substitution levels for different products.

13.
Carbohydr Polym ; 291: 119571, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35698392

RESUMEN

A porous starch-based carrier coated with chitosan-phytic acid was designed for oral administration to improve drug delivery to the colon. Using hydrophobic paclitaxel as a model drug, improved drug loading (15.12% ±â€¯0.31%) and entrapment efficiency (86.63 ±â€¯1.30%) of porous starch were achieved by size/shape matching and adsorption force. Fluorescent paclitaxel particles inside starch were captured clearly. Furthermore, chitosan-phytic acid was added as a second protection since porous starch showed a dissolution rate of only 14.98-20.27% during the simulated digestion in stomach and small intestine, which was far lower than that of raw paclitaxel in porous starch (59.65 ±â€¯2.57%). The release curve in the colon was also obtained and showed that 86.98 ±â€¯2.90% of the drug was released. Finally, we verified the non-covalent interactions between starch and paclitaxel. This showed that the retention of paclitaxel into porous starch decreased once hydrogen bonding stopped. The hydrophobic CH-π effect provides a binding complementing contribution.


Asunto(s)
Quitosano , Almidón , Adsorción , Quitosano/metabolismo , Colon/metabolismo , Preparaciones de Acción Retardada/metabolismo , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Excipientes/metabolismo , Microesferas , Paclitaxel/química , Ácido Fítico , Porosidad , Almidón/química
14.
Carbohydr Polym ; 291: 119628, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35698420

RESUMEN

Paclitaxel, a clinical chemotherapy drug commonly used in the past few years, is greatly limited by its low therapeutic index. Starch and its derivatives have gained wide interest from researchers owing to their unique hydrophilic and hydrophobic properties resulting from their various modifications, which exert the effect-enhancing and toxicity-reducing activity to paclitaxel in vivo and in vitro. This review summarizes the research progress toward different kinds of starch-based carriers, whether oral or injectable. In addition, we discuss the complex properties of starch derivatives toward physically complexed or chemically conjugated paclitaxel. The corresponding complex configurations are suggested. Starch-based carriers can act as permeability enhancers because they may interact with the unstirred water layer that separates hydrophobic drugs from biological membranes, even altering the barrier properties of the membrane. The information presented in this review may be used as a reference for future hydrophobic drug carrier studies.


Asunto(s)
Paclitaxel , Almidón , Portadores de Fármacos/química , Excipientes , Interacciones Hidrofóbicas e Hidrofílicas , Paclitaxel/química , Almidón/química
15.
Front Nutr ; 9: 1003657, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36118753

RESUMEN

The study aims to evaluate the relationships between characteristics of regional rice raw material and resulting quality of rice noodles. Four of most commonly used rice cultivars in Guangxi for noodles production were investigated. The results showed that compositions of rice flour primarily affected gelatinization and retrogradation, which then influenced the textural and sensory properties of rice noodles. Amylose content had strong positive correlation with peak viscosity (PV) and trough viscosity (TV) of rice flour (P < 0.01). PV and TV had strong negative correlations with adhesive strength (P < 0.01) and positive correlations with chewiness (P < 0.05), hardness, peak load and deformation at peak of rice noodles (P < 0.01). Protein content had positive correlation with the Setback of rice flour (P < 0.05), which is known to have influences on retrogradation. In addition, solubility had positive correlations with cooking loss (P < 0.01) and broken rate (P < 0.05) of rice noodles and strong negative correlation with its springiness (P < 0.01). Swelling power had negative correlation with broken rate (P < 0.05). As sensory score of rice noodles was negatively correlated with broken rate (P < 0.05) and cooking loss (P < 0.01) and positively correlated with springiness (P < 0.01), solubility and swelling power of rice flours were presumed to be useful for predicting consumer acceptability of rice noodles.

16.
J Nanosci Nanotechnol ; 21(2): 962-970, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33183431

RESUMEN

In recent years, mTOR signaling pathway has been found to be the main bridge between TSC1/TSC2 gene mutation and tuberous sclerosis phenotype. Although mTOR inhibitors have been reported to treat tuberous sclerosis in foreign countries, there is still a lack of long-term follow-up results and clinical treatment experience in children. Therefore, research at home and abroad is actively focusing on the mTOR signaling pathway to further clarify the pathogenesis of the disease, and from a clinical point of view, to summarize the clinical data of more patients treated with mTOR inhibitors, to conduct a long-term follow-up and exploration of rapamycin treatment, and to summarize mature treatment experience. This is also the research hotspot of tuberous sclerosis. Based on the study of the treatment of tuberous sclerosis patients with rapamycin nanomicelles by abdominal ultrasound, the therapeutic effect and safety were compared and evaluated through the observation and description of the clinical seizure control and the recovery of EEG peak out of rhythm in children with tuberous sclerosis and infantile spasm.


Asunto(s)
Esclerosis Tuberosa , Niño , Humanos , Transducción de Señal , Sirolimus/uso terapéutico , Esclerosis Tuberosa/diagnóstico por imagen , Esclerosis Tuberosa/tratamiento farmacológico , Esclerosis Tuberosa/genética
17.
Food Chem ; 352: 129350, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33657481

RESUMEN

Fermented cassava products are important starchy food staples in South America. The quality of the products is affected by the baking expansion ability of the dough, which is in turn influenced by the starch fermentation process and drying method employed. We investigated the structural properties of cassava starch after different fermentation and drying treatments, and the effect of starch structure on scalding of dough and baking expansion ability. Fermentation combined with either exposure to sunlight or UV light treatment resulted in high cassava starch baking expansion. Moreover, we observed decreased crystallinity and increased disordered crystalline regions with lower molecular weight in the two types of starch-fermented combined with sunlight or UV light treatment-and both appeared to have a continuous network structure and polarized cross in scalded dough, which are conducive to holding gas and losing water, thus promoting high baking expansibility.


Asunto(s)
Manipulación de Alimentos , Manihot/química , Almidón/química , Desecación , Fermentación , Manihot/efectos de la radiación , Peso Molecular , Luz Solar , Rayos Ultravioleta
18.
Int J Biol Macromol ; 146: 1060-1068, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31739049

RESUMEN

The effects of adding guar and xanthan gums on the pasting and gel properties of high-amylose corn starches, Hylon V (~50% amylose content) and NF-CG170 (~71% amylose content), were studied with waxy corn starch as a control, using an ultra-high temperature heating process (up to 130 °C) to gelatinize starches. Interaction between dispersed amylose and hydrocolloids contributed to the earlier onset of viscosity increase during pasting process (lower pasting temperatures) and strong synergistic effects in the peak, setback, and final viscosities with high-amylose starches, phenomena that were more pronounced when amylose content was higher. Conversely, addition of guar and xanthan gums to waxy corn starch resulted in higher pasting temperatures. After held at 5 °C for 2 h, the gelatinized high-amylose starch/hydrocolloid formed stronger and more elastic gels (higher G' and tanδ) with denser microstructure and thicker gel skeleton, compared to starch alone. Compared to xanthan gum, guar gum displayed a much stronger synergistic effect with Hylon V in gel strength, while their difference in synergistic effect was less pronounced with NF-CG170, indicating that amylose dominated gel properties when at a high content (i.e., ~ 71% in starch).


Asunto(s)
Amilosa/química , Galactanos/química , Geles/química , Mananos/química , Gomas de Plantas/química , Polisacáridos Bacterianos/química , Almidón/química , Zea mays/química , Elasticidad , Tamaño de la Partícula , Reología , Viscosidad
19.
Int J Biol Macromol ; 145: 965-973, 2020 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-31614157

RESUMEN

Naturally fermented and sundried tapioca starch is reportedly the traditional material for polvilho azedo and the primary ingredients of gluten-free food items in Brazil. This study aimed to investigate starch structure and expansion rate, high rate is acclaimed in baking application, changes of tapioca starch and potato starch during combinatorial fermentation and drying. The rate of expansion changed from 3.37 mL/g in native tapioca starch to 3.71 mL/g in fermented oven-dried tapioca starch and 6.97 mL/g in fermented sun-dried tapioca starch, while potato starch sample displayed lesser expansion on all treatments. Rapid viscosity analysis, size-exclusion chromatography, X-ray diffraction (XRD), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) and electron paramagnetic resonance spectrometry (EPR) were performed to determine the structure and investigate its relationship with the expansion rate. Fermentation attacked amorphous area and cleaved glycosidic bonds. Sunlight exposure facilitated complex interactions, and crosslinking increased the molecular weight distribution (MWD) in fermented sun-dried potato starch and led to depolymerization in tapioca starch. EPR revealed an initial free radical distribution in both starches, and our results show that intensity changes in tapioca starch are essential for a high expansion capacity.


Asunto(s)
Desecación/métodos , Fermentación , Manihot/química , Solanum tuberosum/química , Almidón/química , Amilopectina/química , Brasil , Alimentos Fermentados , Glútenes , Lactobacillus plantarum , Peso Molecular , Sistema Solar , Viscosidad
20.
Int J Biol Macromol ; 149: 246-255, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-31958556

RESUMEN

The pasting behavior of rice starch and its relationship with cooking properties of rice have been extensively studied. However, the viscosity changes of rice starch and flour under conventional cooking mode and high temperature and high pressure (HTHP) mode remain unknown. In this study, three typical rice starches and seven rice flours of different types and varieties were used to evaluate the effect of cooking modes on their pasting behaviors. A detailed discussion about the relationships among chemical composition, thermal properties, and crystallinity were conducted to explain the different pasting behaviors of the rice samples. The pasting behavior of rice starch was found to be similar with rice flour under standard and conventional heating modes, while remarkably different when treated at different HTHP levels, especially for sticky rice flour. The morphological changes of rice samples at 95 °C and 120 °C confirmed that high temperature long time heating caused extending of molecules, which exhibited layered structure at 120 °C. The rice flour samples showed different morphologies after heating at different modes due to varied amylose content and crystallinity, which contributed to different pasting behavior. These results provide useful information for developing strategies to control rice cooking and improve eating quality.


Asunto(s)
Amilosa/química , Harina , Oryza/química , Almidón/química , Culinaria , Calefacción , Calor , Viscosidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA