Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
Int J Biol Macromol ; 268(Pt 1): 131699, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38642689

RESUMO

Starch and peanut oil (PO) were widely used to improve the gel properties of surimi, however, the impact mechanism of addition forms on the denaturation and aggregation behavior of myofibrillar protein (MP) is not clear. Therefore, the effect of starch, PO, starch/PO mixture, and starch-based emulsion on the physicochemical and gel properties of MP was investigated. The results showed that amylose could accelerate the aggregation of MP, while amylopectin was conducive to the improvement of gel properties. The addition of PO, starch/PO mixture, or starch-based emulsion increased the turbidity, solubility, sulfhydryl content of MP, and improved the gel strength, whiteness, and texture of MP gel. However, compared with starch/PO mixture group, the gel strength of MP with waxy, normal and high amylose corn starch-based emulsion increased by 22.68 %, 10.27 %, and 32.89 %, respectively. The MP containing emulsion had higher storage modulus than MP with starch/PO mixture under the same amylose content. CLSM results indicated that the oil droplets aggregated in PO or starch/PO mixture group, while emulsified oil droplets filled the protein gel network more homogeneously. Therefore, the addition of starch and PO in the form of emulsion could effectively play the filling role to improve the gel properties of MP.


Assuntos
Amilose , Emulsões , Géis , Óleo de Amendoim , Amido , Amilose/química , Amilose/análise , Óleo de Amendoim/química , Amido/química , Géis/química , Emulsões/química , Proteínas Musculares/química , Fenômenos Químicos , Solubilidade , Miofibrilas/química
2.
Arch. latinoam. nutr ; 72(3): 185-195, sept. 2022. tab
Artigo em Inglês | LILACS, LIVECS | ID: biblio-1399261

RESUMO

Introduction: Rice is a staple food in Costa Rica representing almost 24 % of the total calorie intake in the diet. Consumers have become more quality conscious about the rice consumed, so producers need to focus on the quality of rice along with production. Objective: The aim of this study was to investigate the physicochemical profile and consumer preference of five Costa Rican rice varieties: Palmar 18, Basmatico, Chin Chin, INTA-Miravalles, and CR- 5272. Materials and methods: Proximate analysis, amylose, and mineral content were performed in the raw grain. Two different sessions were performed (n=120 each) to evaluate consumer preference measurements using the John Brown R-Index (RJB) index. The first sensory panel selected the best cooking preparation and the second, the preferred rice variety. Instrumental color measurements (L*, C*, hº, DE) were applied to the cooked rice varieties (76-96ºC for 38 min). Results: Regarding the physicochemical characterization, INTAMiravalles showed the highest protein content (8.2%), while Basmatico and Chin Chin, the lowest. Four varieties presented high amylose content (AC) and INTA-Miravalles reported an intermediate AC. The mineral content varied among varieties. INTA-Miravalles showed the highest N, followed by Palmar 18. The cooking preparation from the regulatory agency was preferred by consumers. The consumers' preference of the varieties ranked from high to low: Basmatico>Chin Chin=CR5772>Palmar 18=INTA-Miravalles. Conclusions: This study suggests that consumer preference for cooked rice was influenced by physicochemical characteristics such as protein, AC, mineral content, and aromatic attributes. Consumer acceptance is an important factor to consider when new varieties are developed. The water-to-rice ratio during cooking played an important role in cooked rice sensory quality(AU)


Introducción: el arroz es un alimento básico de consumo en Costa Rica que representa casi el 24% de la ingesta total de calorías en la dieta. Los consumidores se han vuelto más conscientes de la calidad del arroz que consumen, por lo que los productores deben enfocar esfuerzos en la calidad y producción del arroz. Objetivo: El objetivo de este estudio fue investigar el perfil fisicoquímico y la preferencia del consumidor de cinco variedades de arroz de Costa Rica: Palmar 18, Basmatico, Chin Chin, INTA-Miravalles y CR-5272. Materiales y métodos: Se realizó el análisis proximal, contenido de amilosa (CA) y de minerales en el grano crudo y color instrumental en el arroz cocido. Se realizaron dos mediciones de preferencia de los consumidores (n=120) utilizando el índice R de James Brown (RJB). En la primera se seleccionó el mejor método de preparación y en la segunda, la variedad de arroz preferido. El color instrumental (L*, C*, hº, DE) se midió a las variedades de arroz cocinado (76-96ºC por 38 min). Resultados: Miravalles mostró el mayor contenido en proteínas (8,2%), mientras que Basmatico y Chin Chin, el menor. Cuatro variedades presentaron un alto CA y el INTAMiravalles reportó un CA intermedio. El contenido mineral varió entre las variedades. INTA-Miravalles mostró el mayor contenido de nitrógeno, seguido de Palmar 18. El método de cocción del ente regulador fue el preferido por los consumidores. La preferencia de los consumidores por las variedades de mayor a menor fue: Basmatico > Chin Chin = CR5772 > Palmar 18 = INTA-Miravalles. Conclusiones: La preferencia de los consumidores por el arroz cocido se vio influenciada por características fisicoquímicas como proteína, CA, minerales y atributos aromáticos. La aceptación de los consumidores es un factor importante cuando se desarrollan nuevas variedades. La relación agua/ arroz durante la cocción desempeñó un papel importante en la calidad del arroz cocido(AU)


Assuntos
Humanos , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Oryza/química , Comportamento do Consumidor , Ingestão de Alimentos , Olfato , Cor , Costa Rica , Manipulação de Alimentos , Amilose/análise , Minerais/análise
3.
Genes (Basel) ; 13(3)2022 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-35328063

RESUMO

Rice is one of the most important crops in Egypt. Due to the gap between the demand and the availability of the local edible oils, there is need to raise the nutritional value of rice and, therefore, to improve the nutritional value of the consumer. This research was carried out at the Experimental Farm of Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt, during the 2019 and 2020 seasons. Five newly developed genotypes of rice, namely NRL 63, NRL 64, NRL 65, NRL 66, and Giza 178 as check variety (control), were used to evaluate the analytical characterization of raw rice bran and rice bran oil from rice bran, study the genetic variability and genetic advance for various quantitative and qualitative traits in rice as well as, rice bran oil. The genotypes were evaluated in a randomized complete block design (RCBD) with three replications. Analysis of variance revealed highly significant variations among the genotypes for all the studied characters. Data revealed that high estimates of the phenotypic coefficient of variance (PCV%) and genotypic coefficient of variance (GCV%) were observed for amylose content percentage, peroxide value (meq/kg oil), myristic C14:0, and arachidic C20:0, indicating that they all interacted with the environment to some extent. The line NRL66 and NRL64 showed the highest and high values of mean performance for grain yield (t/h), grain type (shape), amylose content percentage, crude protein, ether extract and ash of milled rice, crude protein, ether extract, ash, phosphorus, magnesium, manganese, zinc, and iron of stabilized rice bran oil. Genetic advance as a percentage of mean was high for most of the studied traits. It indicates that most likely, the heritability is due to additive gene effects, and selection may be effective. The percentage of advantage over the Giza 178 as the commercial variety was significant and highly significant among the genotypes for all the characters studied in the two years, indicating that the selection is effective in the genetic improvements for these traits.


Assuntos
Oryza , Amilose/análise , Éter , Oryza/genética , Extratos Vegetais , Óleo de Farelo de Arroz
4.
Int J Biol Macromol ; 172: 439-451, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453260

RESUMO

The aim of this research work was to investigate novel tools given by nanotechnology and green chemistry for improving the disadvantages typically associated to the starch-based films: water susceptibility and brittle mechanical behavior. With this in mind, four food packaging film systems were developed from corn starch or corn starch nanocrystals (SNCs), and modified by phosphating under reactive extrusion (REx) conditions using sodium tripolyphosphate (Na5P3O10 - TPP) as a crosslinker. The structural, physicochemical, thermal, rheological and mechanical properties, as well as studies associated with the management of carbohydrate polymer-based plastic wastes (biodegradability and compostability) were carried out in this study. The hierarchical structure and the modification of the starch were dependent on the amylose content and degree of substitution (DS), which in turn depended on the hydrogen (H)-bonding interactions. In both cases, a higher molecular ordering of the starch chains in parallel was decisive to obtain the self-assembled thermoplastic starches. Beyond the valuable results obtained and scientifically analyzed, unfortunately none of the manufactured materials achieved to improve their performance compared to the control film (thermoplastic starch - TPS). It was even thought that the phosphated starch-based films could fertilize lettuce (Lactuca sativa) seedlings during their biodegradation, and this was not achieved either. This possibly due to the low content of phosphorus or its poor bioavailability.


Assuntos
Embalagem de Alimentos/métodos , Nanopartículas/química , Polifosfatos/química , Amido/química , Amilose/análise , Humanos , Ligação de Hidrogênio , Membranas Artificiais , Nanopartículas/ultraestrutura , Fosforilação , Amido/isolamento & purificação , Zea mays/química
5.
Int J Biol Macromol ; 146: 311-319, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899241

RESUMO

The objective was to characterize thermal and viscosity properties of flour of purple maize from Argentina, and to evaluate the environmental effects on composition and flour properties. Half-sib families were selected from original germplasm and reproduced during 2014 and 2015. Chemical composition, thermal and pasting properties of whole grain flour were determined. Non-purple genotypes were used as controls. Composition of purple maize did not show significant differences with controls, but amylose content was significantly lower. High variability in pasting and thermal properties of flour was observed between genotypes. Anthocyanin content positively correlated with breakdown (r = 0.37, P < 0.05), indicating that anthocyanins increased starch granules fragility during cooking. The higher gelatinization enthalpy of purple genotypes was coincident with the lower amylose content in relation to non-purple. The amylopectin retrogradation enthalpy negatively correlated with polyphenols (r = -0.35, P < 0.05) and anthocyanins (r = -0.40, P < 0.05), probably due to interactions formed after starch gelatinization. Flour functionality parameters showed higher effect of genotype and lower effects of environment and genotype × environment interaction. The variability found among genotypes indicates different flour behavior that would facilitate the identification of progenies with particular properties for production of functional maize based-foods.


Assuntos
Amilopectina/análise , Amilose/análise , Clima , Farinha/análise , Análise de Alimentos , Zea mays , Argentina , Zea mays/química , Zea mays/crescimento & desenvolvimento
6.
J Food Biochem ; 43(7): e12839, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31353738

RESUMO

The objective of this study was to know about the effect of simple parboiling on physical properties, proximate composition, phenolic compounds, and antioxidant activity.  These were  studied in raw and parboiled paddy varieties as well as bioaccessibility of specific nutrients (minerals, starch, and antioxidants). The pigmented rice paddy varieties such as Jyothi, Meter & Athikaraya were parboiled by hot soaking treatment after soaking for 2, 2½, and 3 hr. Athikaraya rice showed high protein, low ash in raw and parboiled than other varieties. Amylose equivalents of all three varieties exhibited in the range of 24%-27% (d.b). Whereas, the soluble amylose content showed 12.7, 8.7, and 7.7% (d.b) in Athikaraya, Meter and Jyothi rice varieties, respectively. Jyothi rice showed less cooking time and more cooking volume. Athikaraya showed high phenolic content and antioxidant properties compared to other two varieties. The dialysability of minerals, starch, and antioxidants were increased due to simple hot soaking parboiling. PRACTICAL APPLICATIONS: The present study has the significance in assessing the variation among different pigmented rice varieties after parboiling by simple hot soaking with various soaking periods. The industrial advantage of this method is, there is no usage of boiler for cooking the paddy by steam, which was economically better. The information gained by this study might be beneficial for consumers and suppliers regarding the quality of the selected pigmented rice varieties with respect to nutrient composition, antioxidant activities, and bioaccessibility of minerals, starch, and antioxidants. Ultimately, the present study can lead to better appreciation of pigmented rice and assist food processors in selecting rice variety with unique characteristics for specialty food preparations.


Assuntos
Culinária/métodos , Oryza/química , Sementes/química , Amilose/análise , Antioxidantes/análise , Digestão , Minerais/análise , Nutrientes/análise , Fenóis/análise , Amido/análise
7.
Food Chem ; 298: 124949, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260990

RESUMO

Starch digestibility and polyphenol content were investigated in six (white, red and purple) Thai rice varieties. Total phenolic content (TPC), total anthocyanin content (TAC), amylose content, gelatinization parameters and in vitro digestibility were determined. Purple and red rice varieties were found to have the highest levels of TPC, TAC and amylose content. TAC was not detected in white rice, while purple rice had the highest values. Gelatinization parameters were determined using differential scanning calorimetry. Red rice (Sung Yod) showed the highest gelatinization enthalpy. Non-pigmented rice (Hom Mali) in both purified starch and flour showed the highest starch digestibility, with a total starch digestibility of 76.85% and a digestion rate of 0.25 min-1. In contrast pigmented rice varieties showed lower starch digestibility. These results suggest that pigmented rice varieties are a source of phenolics and anthocyanin and also a possible good source of low digestible starch to develop as functional food products.


Assuntos
Antocianinas/análise , Oryza , Amido/química , Amilose/análise , Varredura Diferencial de Calorimetria , Digestão , Farinha/análise , Humanos , Oryza/química , Oryza/metabolismo , Fenóis/análise , Pigmentação , Amido/farmacocinética , Tailândia
8.
Food Chem ; 287: 28-37, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30857700

RESUMO

The absorption of oil during frying has important implications for food quality, cost, and nutrition. Maize starches with low (WMS), intermediate (NMS), and high amylose (HAMS) contents were therefore heated in oil to mimic the frying process, and the impact of amylose content on the hierarchical structures and oil absorption of the fried starches was evaluated. Amylose affected the oil absorption by interfering with the structural evolution of the starch or by directly interacting with the lipids during frying. At low moisture level (20%), the granular state was preserved after frying and so the size and porosity of the granules played a dominant role in the oil absorption process, explaining why the highest oil absorption occurred in WMS. At 40% moisture content, NMS absorbed the most oil because of its granular morphology and lower crystallinity. At 60% moisture content, HAMS absorbed more oil than NMS, because more amylose molecules in HAMS provided more hydrophobic helical cavities available for lipids.


Assuntos
Amilose , Culinária , Óleos de Plantas , Amido , Zea mays/química , Amilose/análise , Amilose/química , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Amido/análise , Amido/química , Zea mays/metabolismo
9.
Gut Microbes ; 10(3): 367-381, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30359203

RESUMO

Chronic disruption of the intestinal microbiota in adult cystic fibrosis (CF) patients is associated with local and systemic inflammation, and has been linked to the risk of serious comorbidities. Supplementation with high amylose maize starch (HAMS) might provide clinical benefit by promoting commensal bacteria and the biosynthesis of immunomodulatory metabolites. However, whether the disrupted CF gut microbiota has the capacity to utilise these substrates is not known. We combined metagenomic sequencing, in vitro fermentation, amplicon sequencing, and metabolomics to define the characteristics of the faecal microbiota in adult CF patients and assess HAMS fermentation capacity. Compared to healthy controls, the faecal metagenome of adult CF patients had reduced bacterial diversity and prevalence of commensal fermentative clades. In vitro fermentation models seeded with CF faecal slurries exhibited reduced acetate levels compared to healthy control reactions, but comparable levels of butyrate and propionate. While the commensal genus Faecalibacterium was strongly associated with short chain fatty acid (SCFA) production by healthy microbiota, it was displaced in this role by Clostridium sensu stricto 1 in the microbiota of CF patients. A subset of CF reactions exhibited enterococcal overgrowth, resulting in lactate accumulation and reduced SCFA biosynthesis. The addition of healthy microbiota to CF faecal slurries failed to displace predominant CF taxa, or substantially influence metabolite biosynthesis. Despite significant microbiota disruption, the adult CF gut microbiota retains the capacity to exploit HAMS. Our findings highlight the potential for taxa associated with the altered CF gut microbiotato mediate prebiotic effects in microbial systems subject to ongoing perturbation, irrespective of the depletion of common commensal clades.


Assuntos
Bactérias/metabolismo , Fibrose Cística/microbiologia , Fermentação , Prebióticos , Amido/química , Amido/metabolismo , Adulto , Amilose/análise , Amilose/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Ácidos Graxos Voláteis/metabolismo , Fezes/química , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Humanos , Masculino , Metaboloma , Metagenoma , Pessoa de Meia-Idade , Prebióticos/análise , RNA Ribossômico 16S/genética , Adulto Jovem
10.
Br J Nutr ; 118(5): 353-359, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28901894

RESUMO

This study aimed to evaluate the effect of different starch types on liver nutrient metabolism of finishing pigs. In all ninety barrows were randomly allocated to three diets with five replicates of six pigs, containing purified waxy maize starch (WMS), non-waxy maize starch (NMS) and pea starch (PS) (the amylose to amylopectin ratios were 0·07, 0·19 and 0·28, respectively). After 28 d of treatments, two per pen (close to the average body weight of the pen) were weighed individually, slaughtered and liver samples were collected. Compared with the WMS diet, the PS diet decreased the activities of glycogen phosphorylase, phosphoenolpyruvate carboxykinase and the expression of phosphoenolpyruvate carboxykinase 1 in liver (P0·05). Compared with the WMS diet, the PS diet reduced the expressions of glutamate dehydrogenase and carbamoyl phosphate synthetase 1 in liver (P<0·05). PS diet decreased the expression of the insulin receptor, and increased the expressions of mammalian target of rapamycin complex 1 and ribosomal protein S6 kinase ß-1 in liver compared with the WMS diet (P<0·05). These findings indicated that the diet with higher amylose content could down-regulate gluconeogenesis, and cause less fat deposition and more protein deposition by affecting the insulin/PI3K/protein kinase B signalling pathway in liver of finishing pigs.


Assuntos
Ração Animal/análise , Dieta/veterinária , Fígado/metabolismo , Amido/administração & dosagem , Alanina Transaminase/sangue , Alanina Transaminase/genética , Amilopectina/administração & dosagem , Amilopectina/análise , Amilose/administração & dosagem , Amilose/análise , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/genética , Glicemia/metabolismo , Carbamoil-Fosfato Sintase (Amônia)/genética , Carbamoil-Fosfato Sintase (Amônia)/metabolismo , Ácido Graxo Sintases/sangue , Ácido Graxo Sintases/genética , Gluconeogênese , Glutamato Desidrogenase/genética , Glutamato Desidrogenase/metabolismo , Insulina/metabolismo , Metabolismo dos Lipídeos/genética , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Pisum sativum/química , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais , Suínos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Zea mays/química
11.
Arch. latinoam. nutr ; 67(1): 56-61, mar. 2017. tab, graf
Artigo em Espanhol | LIVECS, LILACS | ID: biblio-1022402

RESUMO

La espectroscopia de infrarrojo cercano NIRS (por sus siglas en inglés) se emplea para el control de calidad de los alimentos. La determinación de amilosa en el arroz es un carácter heredable que correlaciona con la calidad del grano, importante en los programas de fitomejormaiento de arroz. El presente trabajo, establece la viabilidad de evaluar el contenido de amilosa en el arroz con la técnica NIRS. Inicialmente, se determinó entre arroz paddy o integral, cuál es el más apropiado para evaluar amilosa empleando NIRS. Se tomaron espectros a las 540 materiales de arroz procedentes del germoplasma del Fondo Latinoamericano para Arroz de Riego FLAR, y posteriormente se hizo análisis de componentes principales y análisis de regresión múltiple en cada tipo de arroz. El arroz integral fue el que obtuvo mejores resultados estadísticos. En el desarrollo de la calibración se empleó como referencia otra calibración en NIRS basada en harina de arroz con un R2=0.9 de calibración y R2= 0.78 de validación, y se empleó Winisi para desarrollar la quimiometría. Se utilizó mínimos cuadrados parciales MPLS y una matemática de 2,1,1,2; longitud de onda de1100-2492,2, lo que arrojó un R2≥0.68 de validación externa,aceptable para caracterizar las generaciones tempranas, con aproximadamente el 83% de aciertos. Los programas de fitomejoramiento del FLAR evalúan 15.000 materiales en el año en las generaciones tempranas, lo que significa US$ 3.600 dólares y 45 días menos que evaluar con la calibración de harina de arroz, siendo la que actualmente se emplea en el FLAR(AU)


The determination of amilosa in the rice is an inheritable character that it correlates with the quality of the grain, importantly breeder rice. The present work, it establishes the viability of evaluating the content of amilosa in the rice with the technology NIRS. Initially, paddy or integral decided between rice, which is most adapted to evaluate amilosa using NIRS. Spectra took to 540 materials of rice of the germplasms banks of the Latin American Found for Irrigated Rice. FLAR, and later there was done analysis of principal components and analysis of multiple regression in every type of rice. The brown rice was the one that most better statistical results. In the development of the calibration another calibration used as reference in NIRS based on flour of rice with a R2 = 0.9 of calibration and R2 = 0.78 of validation, and Winisi was used to develop the chemometrie. There was in use square minimums partial MPLS and a mathematics of 2,1,1,2; wavelength de1100-2492,2, which a R2 = 0.68 of external, acceptable validation to characterize the early generations, with approximately 83 % of successes. The programs breeding of the FLAR evaluate 15.000 materials in the year in the early generations, which means US$ 3.600 dollars and 45 days less that to evaluate with the calibration of flour of rice, being the one that nowadays is used in the FLAR(AU)


Assuntos
Humanos , Oryza , Qualidade dos Alimentos , Farinha , Amilose/análise , Análise Espectral , Abastecimento de Alimentos , Tecnologia de Alimentos
12.
Food Funct ; 7(2): 1040-7, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26762720

RESUMO

The prevalence of type 2 diabetes mellitus is rapidly increasing all over the world and a diet promoting reduced glycaemic excursions in the postprandial phase may help to prevent the disease. In the present study guar gum (GG) and whole grain rye flour or high amylose maize starch (HAM) was combined to design bread products giving low and sustained glycaemia. A meal study was performed with young, healthy subjects and in addition to glucose and insulin, also subjective appetite ratings and biomarkers of appetite, voluntary energy intake at a second meal and markers of fermentation were studied. The combination of GG and rye was superior with improvements in subjective appetite whereas both test products lead to improvements in biomarkers of appetite compared to the white wheat bread reference. The inclusion of GG, rye and/or HAM in bread products show great potential in lowering risk factors associated with insulin resistance and improving acute and semi-acute appetite.


Assuntos
Apetite , Biomarcadores/sangue , Glicemia/metabolismo , Pão , Desjejum , Ingestão de Energia , Adulto , Amilose/análise , Índice de Massa Corporal , Ácidos Graxos não Esterificados/sangue , Feminino , Fermentação , Farinha/análise , Galactanos/química , Polipeptídeo Inibidor Gástrico/sangue , Grelina/sangue , Humanos , Insulina/sangue , Resistência à Insulina , Masculino , Mananas/química , Peptídeo YY/sangue , Gomas Vegetais/química , Período Pós-Prandial , Fatores de Risco , Secale/química , Amido/química , Triticum/química , Grãos Integrais/química , Zea mays/química
13.
Food Chem ; 188: 632-40, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26041241

RESUMO

Starches from five underutilized tubers (canna, potato, Chinese yam, water chestnut, and taro) were extracted to investigate quantitative structure-property relationships (QSPR) in each starch using a combination of X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS). Structural parameters of the tuber starches were determined using the paracrystalline model. Swelling power (SP), water solubility index (WSI), amylose leaching (AML), and thermal properties were also measured. The XRD results indicated that starches from Chinese yam, water chestnut, and taro are C-type starches with relatively high crystallinity (29.23-35.02%). In contrast, canna and potato starches are B-type starches exhibiting lower crystallinity and higher amylose content. The paracrystalline model provided a better fit for the C-type starches than for the B-type starches because the former was highly compressible (indicated by a higher "ß" value). B-type starches, on the other hand, tend to be more rigid along the lamellar repeat direction, requiring the layers to bend to accommodate internal stress. The QSPR analysis showed that three structural parameters, "Ø", "ß", and "Δρu", correlate well with the SP and WSI, and thus can be used to predict certain physicochemical properties.


Assuntos
Amido/química , Amido/ultraestrutura , Difração de Raios X/métodos , Amilose/análise , Relação Quantitativa Estrutura-Atividade
14.
Food Chem ; 172: 433-40, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25442575

RESUMO

The physicochemical properties of starches isolated from 14 rice cultivars produced in China were investigated. These rice starches showed a non-random combination of AAC and GT. Rice starches showed a typical A-type diffraction pattern with the degree of crystallinity ranging from 32.3% (a high AAC rice) to 45.5% (a waxy rice). AAC was significantly correlated with the pasting, thermal and textural properties. The positive correlations were found with PV, HPV, CPV, SB and HD (p<0.05), while the negative corrections were found with SP, ADH, COH, T(o), T(p), T(c) and ΔH (p<0.05). However, AAC had no correlations with BD, PTime and percentage of retrogradation (R%). The degree of crystallinity and GT had a positive correlation with the retrogradation properties. It could be concluded that although AAC was the major factor affecting the physicochemical properties of rice starch, the retrogradation property of rice starch was mainly determined by the degree of crystallinity and GT.


Assuntos
Amilose/análise , Géis/química , Oryza/metabolismo , Amido/química , Adesividade , Dureza , Microscopia Eletrônica de Varredura , Oryza/química , Solubilidade , Amido/isolamento & purificação , Temperatura de Transição , Difração de Raios X
15.
Food Chem ; 172: 528-36, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25442588

RESUMO

The grain and flour characteristics of different field pea (FP) accessions were evaluated. Accessions with higher grain weight had less compact structure with a greater proportion of large-sized starch granules. Accessions with higher protein content had lower starch content, blue value and λ(max) whereas accessions with higher amylose showed higher resistant starch (RS) and final viscosity and lower rapidly digestible starch (RDS). Ca, Zn, K and Fe content vary significantly amongst different accessions and creamish green and white seeds accessions showed higher Fe and Zn content. Yellow coloured accessions (1.36-3.71%) showed lower antioxidant activity as compared to brownish and green coloured accessions (4.06-9.30%). Out of 21 major polypeptides observed (9-100 kDa), 11 showed differential trypsin inhibitory activity (TIA) under non-reducing conditions. Polypeptides of 68, 46, 33 and 22 kDa showed prominent TIA.


Assuntos
Pisum sativum/metabolismo , Proteínas de Plantas/metabolismo , Amilose/análise , Antioxidantes/química , Eletroforese em Gel de Poliacrilamida , Farinha/análise , Metais/análise , Pisum sativum/química , Fenóis/química , Sementes/química , Sementes/metabolismo , Amido/química , Amido/isolamento & purificação , Inibidores da Tripsina/análise , Viscosidade
16.
J Agric Food Chem ; 63(3): 929-42, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25537355

RESUMO

The Chinese chestnut (Castanea mollissima) seed provides a rich source of carbohydrates as food and feed. However, little is known about starch biosynthesis in the seeds. The objectives of this study were to determine seed composition profiles and identify genes involved in starch and sucrose metabolism. Metabolite analysis showed that starch was the major component and rapidly accumulated during seed endosperm development. Amylopectin was approximately 3-fold of amylose content in chestnut starch. Illumina platform-based transcriptome sequencing generated 56671 unigenes in two cDNA libraries from seed endosperms collected at 45 and 75 days after flowering (DAF). A total of 1537 unigenes showed expression differences ≥2-fold in the two stages of seeds including 570 up-regulated and 967 down-regulated unigenes. One hundred and fifty-two unigenes were identified as involved in starch and sucrose metabolism, including 1 for glycogenin glucosyltransferase, 4 for adenylate transporter (brittle1-type), 3 for ADP-glucose pyrophosphorylase (AGP, not brittle2- or shrunken2-type), 3 for starch synthase (SS), 2 for starch branching enzyme, 5 for starch debranching enzyme, 11 for sucrose synthase, and 3 for sucrose-phosphate synthase. Among them, 58 unigenes showed a ≥2-fold expression difference between the 45 and 75 DAF seeds including 11 up- and 47 down-regulated unigenes. The expression of 21 unigenes putatively coding for major enzymes in starch and sucrose metabolism was validated by qPCR using RNA from five seed stages. Expression profiles and correlation analysis indicated that the mRNA levels of AGP (large and small subunits), granule-bound SS2, and soluble SS1 and SS4 were well-correlated with starch accumulation in the seeds. This study suggests that the starch biosynthesis pathway in Chinese chestnut is similar to that of potato tuber/Arabidopsis leaf and differs from that of maize endosperm. The information provides valuable metabolite and genetic resources for future research in starch and sucrose metabolism in Chinese chestnut tree.


Assuntos
Eleocharis/enzimologia , RNA Mensageiro/análise , Sementes/enzimologia , Amido/metabolismo , Sacarose/metabolismo , Amilopectina/análise , Amilose/análise , Eleocharis/genética , Endosperma/química , Endosperma/genética , Perfilação da Expressão Gênica , Glucose-1-Fosfato Adenililtransferase/genética , Reação em Cadeia da Polimerase em Tempo Real , Sementes/genética , Sementes/crescimento & desenvolvimento , Sintase do Amido/genética
17.
J Sci Food Agric ; 94(15): 3296-3304, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25513670

RESUMO

BACKGROUND: Two cultivars of black rice were investigated for the effects of different cooking methods on anthocyanins, total phenolic compounds and antioxidant activities. RESULTS: There was a significant loss of anthocyanins during cooking: roasting resulted in the greatest decrease (94%), followed by steaming (88%), pan-frying (86%) and boiling (77%). Contents of phenolic compounds decreased drastically after cooking, with significantly lower retention in the black rice cultivar that had higher amylose content. DPPH radical-scavenging activity of black rice decreased after cooking. In contrast, metal-chelating activity increased significantly after cooking. Anthocyanins showed a high positive correlation with total phenolic compounds (r2 = 0.936) but a significant negative correlation with metal-chelating activity (r2 = 0.6107). CONCLUSION: The results indicate that cooking degraded anthocyanins and other phenolic compounds, but with a concomitant increase in phenolics from possible degradation of anthocyanins, which resulted in the enhancement of metal-chelating activity.


Assuntos
Antocianinas/análise , Antioxidantes/análise , Culinária/métodos , Oryza/química , Fenóis/análise , Amilose/análise , Quelantes/análise , Sequestradores de Radicais Livres/análise , Temperatura Alta , Sementes/química , Vapor
18.
J Food Sci ; 79(5): C802-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24734785

RESUMO

UNLABELLED: This study investigated the effects of enzyme modification on starch as an effective oil delivery system for bake-only chicken nuggets. Various native starches were hydrolyzed by amyloglucosidase to a hydrolysis degree of 20% to 25% and plated with 50% (w/w, starch dry basis) with canola oil to create a starch-oil matrix. This matrix was then blended into a dry ingredient blend for batter and breader components. Nuggets were prepared by coated with predust, hydrated batter, and breader, and the coated nuggets were steam-baked until fully cooked and then frozen until texture and sensory analyses. The enzyme-modified starches showed a significant decrease in pasting viscosities for all starch types. For textural properties of nuggets, no clear relationship was found between peak force and starch source or amylose content. Sensory attributes related to fried foods (for example, crispness and mouth-coating) did not significantly differ between bake-only nuggets formulated using the enzyme-modified starches and the partially fried and baked ones. The present findings suggest that enzyme-modified starches can deliver sufficient quantity of oil to create sensory attributes similar to those of partially fried chicken nuggets. Further study is needed to optimize the coating formulation of bake-only chicken nugget to become close to the fried one in sensory aspects. PRACTICAL APPLICATION: The food industry has become increasingly focused on healthier items. Frying imparts several critical and desirable product functionalities, such as developing texture and color, and providing mouth-feel and flavor. The food industry has yet to duplicate all of the unique characteristics of fried chicken nuggets with a baking process. This study investigated the application of enzyme-modified starch as an oil delivery system in bake-only chicken nugget formulation in attempts to provide characteristics of fried items. This information is useful to improve the nutritional value of fried food by eliminating the frying process while preserving the desired characteristics of fried products.


Assuntos
Culinária/métodos , Manipulação de Alimentos/métodos , Produtos da Carne/análise , Óleos de Plantas , Amido/química , Paladar , Amilose/análise , Animais , Galinhas , Ácidos Graxos Monoinsaturados , Glucana 1,4-alfa-Glucosidase/metabolismo , Humanos , Hidrólise , Óleo de Brassica napus , Viscosidade
19.
Biosci Biotechnol Biochem ; 77(12): 2419-29, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24317058

RESUMO

Cooked grains of ae rice cultivars are too hard and non-sticky due to the presence of long-chain amylopectin, and ae rice cultivars are therefore called ``super-hard rice'' and cannot be used as table rice. However, they are promising in terms of their bio-functionality such as preventing diabetes. Miso (soybean paste) is a yeast-fermented food, made from steamed soybeans, salt, and inoculated cereals known as koji, made from rice, barley, or soybeans.We investigated the effects of soaking ae mutant rice cultivars in a miso suspension. Their chemical components, physical properties, and enzyme activities were measured under different conditions (milled rice before or after soaking in a 5% barley-koji miso suspension). Rice grains cooked after soaking in the miso suspension were less hard and more sticky than those cooked after soaking in water. Rice grains cooked after soaking in a 5% barley-koji miso suspension maintained high amounts of resistant starch and dietary fiber, and were fortified with polyphenols and isoflavones. Palatable and bio-functional ae rice could therefore be produced by cooking after soaking in a 5% barley-koji miso suspension.


Assuntos
Manipulação de Alimentos/métodos , Hordeum , Fenômenos Mecânicos , Oryza/química , Alimentos de Soja , Paladar , Amilose/análise , Compostos de Bifenilo/química , Fibras na Dieta/análise , Farinha/análise , Glucose/análise , Ácido Glutâmico/análise , Índice Glicêmico , Imersão , Mutação , Oryza/genética , Picratos/química , Polifenóis/análise , Polifenóis/química , Amido/análise , Suspensões , alfa-Amilases/análise
20.
Carbohydr Polym ; 98(1): 477-82, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23987371

RESUMO

The effect of UV-irradiation on four different types of native starch (corn, waxy corn, wheat and potato) have been investigated. Although the changes in the chemical structure of starch specimens were small, indicating good photostability, the samples lost adsorbed water and their crystallinity degree decreased after irradiation. Moreover, a drop in average molecular weight occurred in samples (with the exception of potato starch) as a result of main chain scission. The variations in the properties of investigated specimens of various origin were related to the differences in their structure and macromolecular arrangement. The lowest photostability among the four starches was exhibited by potato starch.


Assuntos
Amido/química , Raios Ultravioleta , Amilose/análise , Peso Molecular , Fotólise , Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA