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1.
Food Chem ; 304: 125434, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31491711

RESUMO

The effect of amylose content in the in vitro digestibility of non-modified and OSA-modified corn starch was studied. Corn starches with different amylose content (waxy, normal and Hylon VII) were treated with 3% OSA solution. In vitro digestibility tests showed that OSA treatment reduced the fraction of fastly digestible starch, an effect that was more pronounced for cooked starch. The amylose content was negatively linked to the decrease of in vitro digestion. HPSEC analysis was conducted to gain insights on the effect of OSA-treatment on in vitro digestibility. The results showed an increase of the molecular weight of starch chains. Besides, the molecular weight increase was similar for amylose and amylopectin fractions. This suggests that OSA could be acting as a cross-linking agent between starch chains, reducing the susceptibility to amylolysis. Overall, OSA treatment induced the formation of more complex starch chains, offering more resistance for amylolytic reactions.

2.
Food Chem ; 298: 125085, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260951

RESUMO

Plantain is a climacteric fruit having economic relevance in several tropical regions. Unripe plantain is an alternative source of indigestible carbohydrates (dietary fibre) and undigestible starch fraction. Unripe plantain flour was explored in this work as an alternative ingredient (whole and pulp) in spaghetti formulations. Chemical composition, cooking quality, texture analysis, and microstructure of spaghetti formulations were analyzed. The microstructure results showed that the presence of fiber in the food matrix helped the reduction of the starch granule swelling in the cooking process. Spaghetti made with whole plantain flour exhibited lower rapidly starch fraction, with increased resistant starch fractions. Overall, the whole unripe plantain flour exhibited good potential for gluten-free spaghetti having highest content of fiber and lower starch digestion rates.


Assuntos
Farinha , Plantago/química , Culinária , Dieta Livre de Glúten , Fibras na Dieta/análise , Digestão , Farinha/análise , Análise de Alimentos , Amido/química
3.
Food Chem ; 292: 1-5, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31054650

RESUMO

The role of raw plantain flour (RPF) and its citric acid (CA)-esterified counterpart (EPF) on the carbohydrate nutritional properties of cookies was investigated. Cookies were elaborated with commercial wheat flour (CWF), RPF, EPF, or a CWF-EPF blend, and assessed for composition, starch digestibility, texture and sensory properties. EPF-cookie showed the lowest digestible starch (DS) content and estimated glycemic index (pGI) (25.0% and 59.3, respectively). Cookies made with CWF-EPF exhibited the highest indigestible fraction values attributed to the synergistic presence of the RS from EPF and the protein and non-starch polysaccharides from CWF. All RPF containing cookies exhibited lower hardness than CWF-cookie. Although the use of RPF decreased consumer's acceptability compared to CWF-cookie, the cookies with EPF showed sensory characteristics of 52-65% compared with the CWF-cookie (100%). This study shows CA esterification of plantain flour as a successful strategy to manufacture cookies with low DS and pGI.


Assuntos
Carboidratos da Dieta/farmacocinética , Farinha , Plantago/química , Adulto , Ácido Cítrico/química , Esterificação , Feminino , Índice Glicêmico , Dureza , Humanos , Masculino , Pessoa de Meia-Idade , Amido , Paladar , Triticum
4.
Int J Biol Macromol ; 132: 119-125, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30926504

RESUMO

The development of starch granules of a banana cultivar (morado variety - Musa AAA subgroup Red dacca) from filamentous shape to semi-spherical and finally to oval shape, was studied. The purity of the extracted starch changed from 83.5% (6 weeks) to 95.4% (16 weeks). Impurities were ascribed to cellulosic and latex fractions responsible for the integrity of the pristine fruit. The amylose content was stabilized at about 29.6% after the 12th week. The thermal analysis showed that the gelatinization enthalpy increased from 5.0 to 11.2 J/g from the 6th to the 12th week, indicating an increased degree of internal molecular organization. The analysis of chain-length distribution and gel permeation chromatography, showing that the content of long chains (B1, B2, and B3+) increased with the development of the starch granule. Also, XRD analysis indicated that C- type X-ray diffraction pattern from early to later phases of development, although the relative crystallinity content increased from 19.3 to 23.5% after 16 weeks of development. FTIR revealed the formation of more ordered structures with the development time. In vitro digestion tests showed that the resistant starch fraction increased from 37.5% for week 6 to 55.5% for week 16.


Assuntos
Digestão , Evolução Molecular , Frutas/crescimento & desenvolvimento , Musa/química , Musa/crescimento & desenvolvimento , Amido/química , Amilopectina/análise , Amilose/análise , Solubilidade , Amido/metabolismo , Temperatura Ambiente
5.
Carbohydr Polym ; 197: 431-441, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30007632

RESUMO

Taro starch has the ability of producing spherical aggregates under spray-drying without the addition of binding agents. This property makes taro starch suitable for microencapsulation of dietary compounds. This study addressed the physical stability of hydrophilic and hydrophobic core materials microencapsulated by spray-drying into taro starch spherical aggregates determined from a thermodynamic standpoint via vapor adsorption isotherms. Ascorbic acid and almond oil were used as compound models. Encapsulation efficiency, GAB sorption parameters, differential and integral thermodynamic properties, Gibb's free energy, entropy-enthalpy compensation, spreading pressure, effective diffusion rate, activation energy and critical water activity were determined. The encapsulation efficiency of ascorbic acid and almond oil was 99% and 56%, respectively. Monolayer moisture content was relatively low for ascorbic acid microcapsules. The adsorption process was driven by entropic mechanisms. The physical stability of taro starch spherical aggregates microcapsules with different core material was guaranteed for a range of water activities and temperatures.

6.
Food Chem ; 263: 201-207, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29784308

RESUMO

The microstructure of cooked gluten-free pasta depends on the ingredients used, and this microstructure affects the starch hydrolysis (SH), the release of phenolic compounds (PC) and their antioxidant capacity (AC). The aim of this study was to evaluate the SD and bioaccessibility of PC during in vitro gastrointestinal digestion of gluten-free pasta and its relationship with the microstructure. The highest SH was during the intestinal phase (≈60%), but pasta with the highest content of unripe plantain and chickpea presented the lowest release of PC (≈60%). The insoluble dietary fibre could be responsible (≈12.5%) for these effects. The cooked pasta showed high AC in the intestinal phase. Regions with gelatinized starch granules in a less dense protein network and other regions with intact or swollen granules surrounded by a protein network were observed. The starch digestion and bioaccessibility of PC were related to the structure of the matrix.

7.
J Sci Food Agric ; 2018 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-29427318

RESUMO

In the last century, starch present in foods was considered to be completely digested. However, during the 1980s, studies on starch digestion started to show that besides digestible starch, which could be rapidly or slowly hydrolysed, there was a variable fraction that resisted hydrolysis by digestive enzymes. That fraction was named resistant starch (RS) and it encompasses those forms of starch that are not accessible to human digestive enzymes but can be fermented by the colonic microbiota, producing short-chain fatty acids. RS has been classified into five types, depending on the mechanism governing its resistance to enzymatic hydrolysis. Early research on RS was focused on the methods to determine its content in foods and its physiological effects, including fermentability in the large intestine. Later on, due to the interest of the food industry, methods to increase the RS content of isolated starches were developed. Nowadays, the influence of RS on the gut microbiota is a relevant research topic owing to its potential health-related benefits. This review summarizes over 30 years of investigation on starch digestibility, its relationship with human health, the methods to produce RS and its impact on the microbiome. © 2018 Society of Chemical Industry.

8.
Plant Foods Hum Nutr ; 72(4): 411-417, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29063352

RESUMO

The phenolic compounds, color and antioxidant capacity of gluten-free pasta prepared with non-conventional flours such as chickpea (CHF), unripe plantain (UPF), white maize (WMF) and blue maize (BMF) were analyzed. Fifteen phenolic compounds (five anthocyanins, five hydroxybenzoic acids, three hydroxycinnamic acids, one hydroxyphenylacetic acid and one flavonol) were identified in pasta prepared with blue maize, and 10 compounds were identified for samples prepared with white maize. The principal component analysis (PCA) led to results describing 98% of the total variance establishing a clear separation for each pasta. Both the proportion (25, 50 and 75%) and type of maize flour (white and blue) affected the color parameters (L*, C ab *, h ab and ΔE* ab ) and antioxidant properties (DPPH, ABTS and FRAP methods) of samples, thus producing gluten-free products with potential health benefits intended for general consumers (including the population with celiac disease).


Assuntos
Antioxidantes/análise , Farinha/análise , Fenóis/análise , Antioxidantes/farmacologia , Cicer/química , Cor , Dieta Livre de Glúten , Análise Multivariada , Plantago/química , Zea mays/química
9.
J Agric Food Chem ; 64(44): 8289-8295, 2016 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-27758103

RESUMO

Provitamin A (proVA) enhanced maize was developed to help alleviate vitamin A deficiency in maize-consuming populations. Nixtamalization (lime-cooking process) is the most commonly used maize-preparation method in Mexico and Central America. In this study, the effect of traditional nixtamalization (TN) and nixtamalized extrusion (NE) on proVA retention was evaluated. Kernel conversion to TN dough led to high proVA apparent retention (>100%), while kernel conversion to NE flour led to lower retention (85%). However, TN tortilla proVA carotenoid concentration was similar to the kernels' original concentration and slightly higher in NE tortillas. Genotypic variation has a strong effect on proVA retention in TN dough and NE flour, but no such variation in proVA retention was observed in tortillas. Tortillas prepared with proVA-enhanced maize, using either TN or NE, are a good source of proVA carotenoids. Also, dough made using TN and proVA-enhanced maize is a high proVA-content ingredient for other food products.


Assuntos
Pão , Carotenoides/química , Manipulação de Alimentos/métodos , Alimentos Fortificados , Zea mays/química , Pão/análise , Carotenoides/análise , Genótipo , Humanos , México , Provitaminas/química , Vitamina A/análise , Zea mays/genética
10.
Food Chem ; 211: 281-4, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27283633

RESUMO

The purpose of this study was to evaluate the effect of blue maize extracts obtained by acid-methanol treatment on the nutritional in vitro starch fractions such as: rapidly digestive starch (RDS), slowly digestive starch (SDS) and resistant starch (RS) of native and gelatinized commercial maize starch. Chromatographic analysis (HPLC-DAD/ESI-MS) of blue maize extracts showed the presence of seven anthocyanins, where cyanidin-3-(6″-malonylglucoside) was the main. Blue maize extracts modified nutritional in vitro starch fractions (decrease of RDS) while RS content increased (1.17 and 2.02 times for native and gelatinized commercial maize starch, respectively) when anthocyanins extracts were added to starch up to 75% (starch weight). This preliminary observation provides the basis for further suitability evaluation of blue maize extract as natural starch-modifier by the possible anthocyanins-starch interaction. Anthocyanin extracts can be a suitable to produce functional foods with higher RS content with potential human health benefits.


Assuntos
Antocianinas/análise , Grão Comestível/química , Pigmentos Biológicos/análise , Amido/análise , Antocianinas/metabolismo , Cromatografia Líquida/métodos , Digestão , Grão Comestível/metabolismo , Espectrometria de Massas/métodos , México , Pigmentos Biológicos/metabolismo , Extratos Vegetais/química , Amido/metabolismo
11.
Carbohydr Polym ; 124: 17-24, 2015 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-25839789

RESUMO

Banana starches from diverse varieties (Macho, Morado, Valery and Enano Gigante) were studied in their physicochemical, structural and digestibility features. X-ray diffraction indicated that the banana starches present a B-type crystallinity pattern, with slight difference in the crystallinity level. Macho and Enano Gigante starches showed the highest pasting temperatures (79 and 78°C, respectively), whilst Valery and Morado varieties presented a slight breakdown and higher setback than the formers. Morado starch presented the highest solubility value and Valery starch the lowest one. The swelling pattern of the banana starches was in agreement with their pasting profile. All banana starches showed a shear-thinning profile. The resistant starch (RS) fraction was the main fraction in the uncooked banana starches. Morado variety showed the highest amount of slowly digestible starch (SDS) and the lowest RS content reported until now in banana starches. Banana starch cooked samples presented an important amount of SDS and RS. Molecular weight and gyration radius of the four banana starches ranged between 2.88-3.14×10(8)g/mol and 286-302nm, respectively. The chain-length distributions of banana amylopectin showed that B1 chains (DP 13-24) is the main fraction, and an important amount of long chains (DP≥37) are present. The information generated from this study can be useful to determine banana varieties for starch isolation with specific functionality.


Assuntos
Musa/química , Amido/química , Peso Molecular , Solubilidade , Difração de Raios X
12.
J Sci Food Agric ; 93(11): 2660-8, 2013 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-23737144

RESUMO

BACKGROUND: The characterization of starch maize with different endosperm type and the proteomic analysis of its biosynthetic enzymes at 20 and 50 days after pollination (DAP) was carried out. RESULTS: There were differences between both endosperm types at 20 DAP, mainly in starch accumulation, amylose content, granule size and crystallinity percentage, whereas at 50 DAP the differences found were not relevant in the case of starch content, granule size, chain length distribution and thermal properties. SSSI, SBEIIb and GBSSI enzymes were identified; however, SBEIIb was only identified in two samples: floury endosperm at 20 DAP and vitreous at 50 DAP. CONCLUSION: Starch did not show differences in its morphological or structural characteristics in either endosperm on reaching maturity. Starch biosynthetic enzymes identified by matrix-assisted laser desorption/ionization-time of flight did not show a relationship to starch structure.


Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Amido/biossíntese , Zea mays/classificação , Zea mays/enzimologia , Amilose , Endosperma/classificação , Endosperma/fisiologia , Endosperma/ultraestrutura , Microscopia Eletrônica de Varredura , Proteínas de Plantas/genética , Difração de Raios X , Zea mays/metabolismo
13.
J Agric Food Chem ; 59(4): 1376-82, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-21214175

RESUMO

Banana starch was chemically modified using single (esterification or cross-linking) and dual modification (esterification-cross-linking and cross-linking-esterification), with the objective to increase the slowly digestible starch (SDS) and resistant starch (RS) concentrations. Physicochemical properties and in vitro digestibility were analyzed. The degree of substitution of the esterified samples ranged from 0.006 to 0.020. The X-ray diffraction pattern of the modified samples did not show change; however, an increase in crystallinity level was determined (from 23.79 to 32.76%). The ungelatinized samples had low rapidly digestible starch (RDS) (4.23-9.19%), whereas the modified starches showed an increase in SDS (from 10.79 to 16.79%) and had high RS content (74.07-85.07%). In the cooked samples, the esterified starch increased the SDS content (21.32%), followed by cross-linked starch (15.13%). Dual modified starch (cross-linked-esterified) had the lowest SDS content, but the highest RS amount. The esterified and cross-linked-esterified samples had higher peak viscosity than cross-linked and esterified-cross-linked. This characteristic is due to the fact that in dual modification, the groups introduced in the first modification are replaced by the functional group of the second modification. Temperature and enthalpy of gelatinization decreased in modified starches (from 75.37 to 74.02 °C and from 10.42 to 8.68 J/g, respectively), compared with their unmodified starch (76.15 °C and 11.05 J/g). Cross-linked-esterified starch showed the lowest enthalpy of gelatinization (8.68 J/g). Retrogradation temperature decreased in modified starches compared with unmodified (59.04-57.47 °C), but no significant differences were found among the modified samples.


Assuntos
Frutas/química , Musa/química , Amido/química , Varredura Diferencial de Calorimetria , Fenômenos Químicos , Reagentes para Ligações Cruzadas , Digestão , Esterificação , Termodinâmica , Difração de Raios X
14.
J Food Sci ; 74(6): S263-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19723232

RESUMO

Banana is a starchy food that contains a high proportion of undigestible compounds such as resistant starch and nonstarch polysaccharides. Products with low glycemic response such as pasta are considered favorable to health. The objective of this study was to use unripe banana flour to make spaghetti with low-carbohydrates digestibility and evaluate its physical and texture characteristics, as well as consumer preference. Formulations with 100% durum wheat semolina (control) and formulations with 3 semolina: banana flour ratios (85: 15, 70: 30, and 55: 45) were prepared for spaghetti processing. The use of banana flour decreased the lightness and diameter of cooked spaghetti, and increased the water absorption of the product. Hardness and elasticity of spaghetti were not affected by banana flour, but adhesiveness and chewiness increased as the banana flour level in the blend rose. Spaghettis prepared in the laboratory (control and those with banana flour) did not show differences in preference by consumers. In general, the preference of spaghettis with different banana flour level was similar. The addition of a source of undigestible carbohydrates (banana flour) to spaghetti is possible without affecting the consumer preference.


Assuntos
Comportamento do Consumidor , Manipulação de Alimentos/métodos , Preferências Alimentares , Frutas/química , Musa/química , Adesividade , Adolescente , Adulto , Idoso , Algoritmos , Criança , Condimentos/análise , Fibras na Dieta/administração & dosagem , Elasticidade , Feminino , Farinha/análise , Tecnologia de Alimentos/métodos , Frutas/crescimento & desenvolvimento , Dureza , Humanos , Lycopersicon esculentum/química , Masculino , Pessoa de Meia-Idade , Pigmentação , Estatística como Assunto , Água/análise , Adulto Jovem
15.
Plant Foods Hum Nutr ; 64(1): 18-24, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19153833

RESUMO

The use of pigmented maize varieties has increased due to their high anthocyanins content, but very few studies are reported about the starch properties of these grains. The aim of this work was to isolate the starch granules from pigmented blue maize and carry out the morphological, physicochemical, and biochemical characterization studies. The proximate composition of starch granules showed high protein contents, after purification, the blue maize starch presented lower protein amount than starch from white maize (control). Although the purity of starch granules was increased, the damaged starch (determined for the Maltase cross absence) was also increased. Scanning electron microscopy showed the presence of some pores and channels in the blue maize starch. The electrophoretic protein profiles showed differences in the bands that correspond to the enzymes involved in the starch biosynthesis; these differences could explain the variation in morphological characteristics of blue maize starches against starch from white maize.


Assuntos
Sintase do Amido/metabolismo , Amido/metabolismo , Zea mays/enzimologia , Zea mays/ultraestrutura , Eletroforese em Gel Bidimensional , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Plantas Geneticamente Modificadas , Amido/análise , Amido/ultraestrutura , Zea mays/química
16.
Interciencia ; 33(9): 658-662, sep. 2008. ilus, tab
Artigo em Inglês | LILACS-Express | ID: lil-630669

RESUMO

Salted noodles were prepared with different contents of wheat grits and plantain starch (PS). The blends were hydrated with 2% NaCl (w/v), homogenized, and the resulting doughs were sheeted through a pasta machine, cut into strips ~30cm in length, cooked, and their composition and in vitro starch digestibility was assessed. Moisture (6.43-7.60%) and ash contents (2.08-3.12%) increased by the addition of PS. Fat level decreased from 0.41 to 0.31% as the substitution of wheat grits increased. Results showed a 7.39% lower total starch content in the control sample as compared to the noodle containing 30% PS. A similar pattern was observed for potentially available starch content, but the difference was greater (12.46%). Approximately 50% of total resistant starch (RS) in the noodles was resistant starch associated to fiber, showing that a part of RS is due to the physically inaccessible and retrograded starch fractions. Pure wheat (control) noodles presented a greater final a-amylolysis value, which is suggestive of potentially lower glycemic impact for the plantain/wheat products.


Se elaboraron tallarines salados con diferentes contenidos de sémola de trigo y almidón de plátano (AP). Las mezclas fueron hidratadas con solución NaCl 2% (p/v), homogenizadas y las masas laminadas en una máquina para elaborar pasta. Se cortaron en tiras de ~30cm de longitud, se cocinaron y se estudió su composición, así como la digestibilidad del almidón in vitro. El contenido de humedad (6,43-7,60%) y cenizas (2,08-3,12%) incrementaron con la adición del AP. El contenido de lípidos disminuyó de 0,41 a 0,31% conforme el nivel de sustitución de la semolina incrementó. El contenido de almidón total fue 7,39% menor en la muestra control comparado con el tallarín con 30% de AP. Un comportamiento similar se encontró en el almidón disponible, pero la diferencia fue mayor (12,46%). Aproximadamente 50% del almidón resistente total (AR) en los tallarines fue almidón resistente asociado a fibra, mostrando que una parte del AR es debido al almidón físicamente inaccesible y al almidón retrogradado. El valor final de la a-amilólisis fue mayor en el control de trigo puro, lo cual sugiere que los tallarines elaborados con la mezcla semolina/AP tienen menor impacto glucémico.

17.
J Sci Food Agric ; 87(14): 2570-5, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20836163

RESUMO

BACKGROUND: Beans are rich and inexpensive sources of proteins and carbohydrates around the world, but particularly in developing countries. However, many legume varieties are still underutilized. In this study, physical characteristics of the seeds of three Phaseolus lunatus cultivars were characterized. Also, the chemical composition and starch digestibility in the cooked beans were assessed. RESULTS: 'Comba floja' variety exhibited the highest thousand-kernel weight whereas the lowest was found in 'comba violenta'. This agrees with seed dimensions: 'comba floja' had the Longest seeds (16.36 mm) and 'comba violenta' the shortest ones (13.98 mm). All samples exhibited high protein content, but levels in 'comba blanca' variety (216 g kg(-1)) were lower than the in other two cultivars. Total starch (370-380 g kg(-1)) and potentially available starch content (330-340 g kg(-1)) were similar in the three varieties. Resistant starch level in the cooked seeds ranged between 38 and 45 g kg(-1). Low enzymatic hydrolysis indices (HI) were recorded (30.2-35%), indicating a low digestion rate for Phaseolus lunatus starch. HI-based predicted glycemic indices ranged between 34% and 39%, which suggests a 'slow carbohydrate' feature for this legume. CONCLUSION: Phaseolus lunatus beans appear to be a good source of protein and slow-release carbohydrates with potential benefits for human health. Copyright © 2007 Society of Chemical Industry.

18.
Interciencia ; 31(12): 881-884, dic. 2006. tab
Artigo em Espanhol | LILACS | ID: lil-453637

RESUMO

Se estudió la composición química y la digestibilidad del almidón de cuatro variedades de frijol común (Phaseolus vulgaris L.). No se encontraron diferencias estadísticas (p£0,05) en el contenido de proteína y el contenido de lípidos fue bajo pero sin diferencias apreciables. Estos frijoles son buena fuente de minerales (3,67-5,15 por ciento cenizas). El valor de almidón total (AT) menor fue para la variedad Flor de Mayo (34,70 por ciento) y el mayor para Peruano (42,81 por ciento) y Mayocoba (40,24 por ciento). Los valores mayores de almidón disponible (AD) se determinaron en las variedades Flor de Mayo (32,27 por ciento) y Peruano (31,60 por ciento), y los menores en las variedades Mayocoba (22,87 por ciento) y Negro (21,7 por ciento). La variedad Flor de Mayo presentó el menor valor (2,43 por ciento) de almidón resistente (AR), y las variedades con el mayor valor de AT (40,24-42,81 por ciento) también tuvieron el valor más alto de AR (5,41-6,4 por ciento). Las variedades Flor de Mayo y Peruano mostraron los mayores porcentajes (p£0,05) de hidrólisis (34-37 por ciento), lo que coincidió con sus valores de AD. La predicción del índice glucémico (pIG) fue mayor en la variedad Peruano (68,69), y menor en Mayocoba (57,88) y Negro (58,40). Estos valores de pIG se consideran bajos


Assuntos
Fabaceae , Amido , Fenômenos Fisiológicos da Nutrição , México
19.
Arch Latinoam Nutr ; 55(1): 86-92, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16187683

RESUMO

Tortilla samples were elaborated by four small commercial factories in Mexico, employing masas prepared with the traditional nixtamalization process. Samples were stored at 4 degrees C for up to 72 hours and their chemical composition and in vitro starch digestibility features were evaluated. Chemical composition did not change with the storage time, but soluble carbohydrates decreased slightly during storage. A significant decrease in available starch content upon storage was observed, concomitant with increased resistant starch (RS) levels. These changes are possibly due to retrogradation. Retrograded resistant starch (RRS) values increased with storage time; in some samples, RRS represented more than 75% of total RS whereas in others it only accounted for 25%. The digestion rate (DR) in the freshly prepared tortillas was similar for the various samples, but after 72 h storage some differences among tortillas were found. Also, when a single tortilla sample was compared throughout the different storage times, lower DRs were determined in samples subjected to prolonged storage, which is related to the concomitant. increase in RRS. The differences found among the various tortilla samples may be due to minor variations in the commercial processing conditions and to the use of different corn varieties.


Assuntos
Digestão , Farinha/análise , Manipulação de Alimentos , Alimentos Fortificados , Amido/análise , Zea mays/química , Análise de Variância , Conservação de Alimentos , Humanos , Técnicas In Vitro , México , Valor Nutritivo , Fatores de Tempo
20.
Arch. latinoam. nutr ; 55(1): 86-92, mar. 2005. tab, graf
Artigo em Inglês | LILACS | ID: lil-419100

RESUMO

Se elaboraron tortillas utilizando masa a partir de cuatro tortillerías, la cual fue obtenida mediante el proceso tradicional de nixtamalización. Las muestras fueron almacenadas a 4 ºC hasta por 72 h y se determinó su composición química y digestibilidad del almidón in vitro. La composición química no cambio con el tiempo de almacenamiento, pero los carbohidratos solubles disminuyeron ligeramente durante el almacenamiento. Se observó que el contenido de almidón disponible disminuyó y el almidón resistente (AR) se incrementó con el tiempo de almacenamiento. Estos resultados se deben posiblemente a la retrogradación del almidón. Los contenidos de almidón resistente retrogradado (ARR) se incrementaron con el tiempo de almacenamiento; en algunas muestras el ARR representó más del 75 por ciento del AR total y en otras muestras fue sólo el 25 por ciento. La velocidad de digestión (VD) en las tortillas recién elaboradas fue similar, pero se encontraron diferencias significativas entre las tortillas almacenadas por 72 h. Al comparar las VDs de las tortillas a los diferentes tiempos, se encontró que disminuyeron significativamente con el tiempo de almacenamiento, lo cual esta relacionado con el incremento en el contenido de ARR. Las diferencias determinadas en las tortillas pudo deberse a variaciones en las condiciones del proceso de nixtamalización que usa cada tortillería así como la variedad de maíz utilizada


Assuntos
Digestão , Amido , Zea mays , México , Nutrição em Saúde Pública , Venezuela
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