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1.
Molecules ; 27(18)2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36144683

RESUMEN

Starch is a biocompatible and economical biopolymer in which interest has been shown in obtaining electrospun fibers. This research reports that cassava (CEX) and pea (PEX) starches pretreated by means of reactive extrusion (REX) improved the starches rheological properties and the availability of amylose to obtain fibers. Solutions of CEX and PEX (30-36% w/v) in 38% v/v formic acid were prepared and the rheological properties and electrospinability were studied. The rheological values indicated that to obtain continuous fibers without beads, the entanglement concentration (Ce) must be 1.20 and 1.25 times the concentration of CEX and PEX, respectively. In CEX, a higher amylose content and lower viscosity were obtained than in PEX, which resulted in a greater range of concentrations (32-36% w/v) to obtain continuous fibers without beads with average diameters ranging from 316 ± 65 nm to 394 ± 102 nm. In PEX, continuous fibers without beads were obtained only at 34% w/v with an average diameter of 170 ± 49 nm. This study showed that starches (20-35% amylose) pretreated through REX exhibited electrospinning properties to obtain fibers, opening the opportunity to expand their use in food, environmental, biosensor, and biomedical applications, as vehicles for the administration of bioactive compounds.


Asunto(s)
Manihot , Amilosa , Pisum sativum , Almidón , Viscosidad
2.
Molecules ; 27(11)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35684467

RESUMEN

Starch is the most abundant carbohydrate in legumes (22-45 g/100 g), with distinctive properties such as high amylose and resistant starch content, longer branch chains of amylopectin, and a C-type pattern arrangement in the granules. The present study concentrated on the investigation of hydrolyzed faba bean starch using acid, assisted by microwave energy, to obtain a possible food-grade coating material. For evaluation, the physicochemical, morphological, pasting, and structural properties were analyzed. Hydrolyzed starches developed by microwave energy in an acid medium had low viscosity, high solubility indexes, diverse amylose contents, resistant starch, and desirable thermal and structural properties to be used as a coating material. The severe conditions (moisture, 40%; pure hydrochloric acid, 4 mL/100 mL; time, 60 s; and power level, 6) of microwave-treated starches resulted in low viscosity values, high amylose content and high solubility, as well as high absorption indexes, and reducing sugars. These hydrolyzed starches have the potential to produce matrices with thermo-protectants to formulate prebiotic/probiotic (symbiotic) combinations and amylose-based inclusion complexes for functional compound delivery. This emergent technology, a dry hydrolysis route, uses much less energy consumption in a shorter reaction time and without effluents to the environment compared to conventional hydrolysis.


Asunto(s)
Almidón , Vicia faba , Amilosa/química , Hidrólisis , Microondas , Almidón Resistente , Almidón/química , Viscosidad
4.
Int J Biol Macromol ; 164: 3429-3437, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32827614

RESUMEN

In this study, hard corn grains were nixtamalized (alkali-heat treatment) by a high-energy ball mill to investigate the effects on its physicochemical, textural, and microstructural properties. Ball milling modifies the structure and properties of cornstarch. The gelatinization peak of starch was evidenced and thermal and pasting properties were significantly affected. With regard to rheological properties, the viscosity peak increased from 2454 cP in traditional nixtamalized flour to 4294 cP in high-energy milling treatments with 1.4% of Ca(OH)2 and 20% moisture content, C1.4, while enthalpy ranged from 3.5 to 0.34 J/g, respectively. High-energy milling influenced the Fourier-Transform InfraRed Spectroscopic (FT-IR) patterns. All of the samples of the corn-grain starches presented the typical A-type X-ray diffraction pattern. The crystallinity of starch from CG showed a lower intensity in peaks 2θ ~ 15 and 23° compared with starch from WG and YG. The textural properties of the masas were influenced, adhesiveness was reduced, but cohesiveness was increased by the addition of Ca(OH)2. In the structural characterization by E-SEM, the control presented a greater amount of agglomerated starch granules, followed by the high-energy milling treatments. The results suggest that high-energy alkaline milling could be a potential physical and chemical method to modify corn-starch properties and obtain nixtamalized products.


Asunto(s)
Álcalis/química , Harina , Manipulación de Alimentos , Almidón/química , Zea mays/química , Fenómenos Químicos , Manipulación de Alimentos/métodos , Termodinámica , Viscosidad , Difracción de Rayos X
5.
Food Technol Biotechnol ; 57(3): 341-349, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31866747

RESUMEN

Phenolic compounds with antioxidant properties are highly sensitive molecules, which limits their application. In response, extruded esterified starch has been proposed as efficient encapsulating material. In this work, we aim to describe the encapsulation of red sorghum phenolic compounds by spray drying using extruded phosphorylated, acetylated and double esterified sorghum starch as wall material. Their respective encapsulation yields were 77.4, 67.4 and 56.8%, and encapsulation efficiency 91.4, 89.7 and 84.6%. Degree of substitution confirmed esterification of the sorghum starch and Fourier transform infrared spectroscopy showed the significant chemical and structural changes in the extruded esterified starch loaded with phenolic compounds. Microcapsules from phosphorylated sorghum starch showed the highest endothermic transition (173.89 °C) and provided a greater protection of the phenolic compounds during storage at 60 °C for 35 days than the other wall materials. Extruded esterified sorghum starch proved to be effective material for the protection of phenolic compounds due to its high encapsulation efficiency and stability during storage.

6.
Foods ; 8(6)2019 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-31151233

RESUMEN

The addition of flaxseed and amaranth on the physicochemical, functional, and microstructural changes of instant-extruded products was evaluated. Six mixtures with different proportions of amaranth (18.7-33.1%), flaxseed (6.6-9.3%), maize grits (55.6-67.3%) and minor ingredients (4.7%) were extruded in a twin-screw extruder. Insoluble and soluble fiber contents in extrudates increased as the proportions of amaranth and flaxseed increased. However, the highest flaxseed proportion had the highest soluble fiber content (1.9%). Extruded products with the highest proportion of flaxseed and amaranth resulted in the highest dietary fiber content and hardness values (5.2 N), which was correlated with the microstructural analysis where the crystallinity increased, resulting in larger, and more compact laminar structure. The extruded products with the highest maize grits proportion had the highest viscosity, expansion, and water absorption indexes, and the lowest water solubility index values. The mixtures with amaranth (18.7-22.9%), flaxseed (8.6-9.3%), and maize grits (63.8-67.3%) resulted in extruded products with acceptable physicochemical and functional properties.

7.
Ultrason Sonochem ; 56: 458-465, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31101284

RESUMEN

In the present research work, esterified nanoparticles with 2-octen-1-ylsuccinic anhydride were synthesized from waxy corn starch, to our knowledge for the first time, in a single step of ultrasonic treatment. First, the ultrasound time to produce non-esterified nanoparticles was studied. The results showed that non-esterified nanoparticles had sizes ranging from 63 to 48 nm, as well as polydispersity indexes (PDI) ranging from 0.458 to 0.224 and ζ-potential values ranging from -16 to -24 mV in ultrasonication times ranging from 20 to 100 min. Succinylated nanoparticles were obtained at 80 min with two degrees of substitution i.e., 0.003 and 0.01, hydrodynamic sizes of 57 and 83 nm, PDI of 0.479 and 0.91, and ζ-potential values of -6.27 and -14.03 mV, respectively. The succinylation of nanoparticles was confirmed by FTIR spectroscopy, and it was possible to elucidate the conversion of amylopectin molecules into amylose blocks. The nanoparticles showed stability during storage in aqueous suspension at 4 °C. By means of the ultrasonic technology, destructuring of the waxy corn starch and, at the same time, the succinylation of the nanoparticles in a total time of 120 min was effectively achieved.

8.
Plant Foods Hum Nutr ; 74(2): 241-246, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31001726

RESUMEN

This study aimed at evaluating the effect of high-energy milling (HEM) and traditional nixtamalization (TN) on bioactive compounds and antioxidant capacity in nixtamalized creole corn flours obtained from a maize genotype cultivated under rainy temporal conditions in the Mexican semidesert. Four creole grains, including San José de Gracia white and blue (WG and BG), Negritas (NG), and Ahualulco white corn grains (SG), were used. For HEM nixtamalization, corn grains were hammer-milled; then, two different conditions were evaluated: treatment H1, with raw flours with 14% moisture content and 1.1% Ca(OH)2, and treatment H2, with raw corn flours with a 23% moisture content and 1.4% Ca(OH)2. The TN process was utilized as a control. TN recorded significant losses in luminosity value L* (p < 0.05), while HEM nixtamalized blue corn flours remained close to -b* values, that is, near to those of raw flour. Anthocyanin content showed higher content values in HEM treatments compared with TN (759.55 and 252.53 mg cyanidin 3-O-ß-D-glucoside (C3G)/kg, respectively) (p < 0.05). Total soluble phenolic content was higher in HEM nixtamalization compared with the traditional process, except for WH2 and SH2 (H2 treatment for WG and SG). Two redundant radical scavenging assays were used: antioxidant capacity (DPPH assay) exhibited less value in nixtamalized flours than in raw flour (p < 0.05). Antioxidant activity by (ABTS) assay was higher in HEM than in TN. Nixtamalized flours produced by HEM demonstrated more improvement in nutraceutical properties than those produced employing TN.


Asunto(s)
Antioxidantes/metabolismo , Manipulación de Alimentos/métodos , Fitoquímicos/metabolismo , Zea mays/química , Antocianinas/análisis , Antocianinas/metabolismo , Antioxidantes/análisis , Suplementos Dietéticos , Grano Comestible/química , Harina/análisis , México , Fenoles/análisis , Fenoles/metabolismo , Fitoquímicos/análisis
10.
Food Chem ; 283: 481-488, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30722902

RESUMEN

High-energy milling (HEM) was used to produce nixtamalized corn flours, the traditional nixtamalization process was used as a control. Four creole grains were stone-milled, adjusted to an appropriate moisture content and calcium hydroxide concentration and milled using HEM. The physicochemical, thermal, and rheological characteristics of the flours and corn masas were affected by the HEM process. Negritas and Ahualulco creole grains nixtamalized by HEM showed similar viscosity profiles as a control. HEM reduced the gelatinization enthalpy compared to control and raw flours. Diffractograms showed changes in the crystalline structures and FT-IR demonstrated different regions for lipids, proteins, and carbohydrates in all control and treated grains. The texture of corn masas revealed significant differences according to the grain type. ESEM analysis showed smaller particles of HEM flours compared to those of the control. HEM could be a faster, non-pollutant, energy-saving, alternative nixtamalization process.


Asunto(s)
Harina , Manipulación de Alimentos/métodos , Zea mays/química , Harina/análisis , Microscopía Electrónica de Rastreo , Reología , Espectroscopía Infrarroja por Transformada de Fourier , Viscosidad , Difracción de Rayos X
11.
Food Chem ; 278: 601-608, 2019 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-30583418

RESUMEN

The aim of this work was to evaluate the effect of the addition of huitlacoche paste to nixtamalized blue-corn flours (NBCF) on the physicochemical, thermal, and rheological properties of masas. Raw blue maize was nixtamalized (hydrothermal alkalinized process), then was wet-milled in a stone mill, masa was dehydrated, pulverized and sieved to obtain NBCF; commercial nixtamalized blue-corn flour (CNBCF) was used as a control. Huitlacoche paste in concentrations of 3, 6, 9, 12, 15, and 18% was added to nixtamalized flours. Characteristics of the blue grain showed its great effects on water absorption, viscosity, and masa cohesiveness; the addition of huitlacoche significantly influenced adhesiveness, water-absorption, color, and the rheological properties (p < 0.05). Values between 0.03 and 0.083 kg-force resulted in masas with optimal adhesiveness. The inclusion of huitlacoche paste can be achieved with a maximal addition of 9% in NBCF for an industrial process and could comprise a new industrialization alternative.


Asunto(s)
Harina/análisis , Ustilago/crecimiento & desarrollo , Zea mays/química , Color , Reología , Solubilidad , Viscosidad , Agua/química , Zea mays/metabolismo
12.
J Food Sci Technol ; 55(7): 2436-2445, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30042559

RESUMEN

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40 °C for 39 days and by using them as pigmenting agent of yogurt at 4 °C during 32 days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok® starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok® starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

13.
J Food Sci Technol ; 55(6): 2279-2287, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29892128

RESUMEN

The encapsulation by spray drying of maize anthocyanins was evaluated using two types of wall materials, consisting of normal and waxy maize starch, which were esterified with octenyl succinic anhydride. The X-ray diffraction analysis revealed that SWMS possessed a completely amorphous, while SNMS had a crystalline structure. SNMS showed peaks at 2θ = 13.1°, 19.8° and 22.4°. The results revealed that SNMS and SWMS had almost the same encapsulation productivity (EP); SNMS showed the best performance because its EP was higher (95%) than in SWMS (90%). The stability of microcapsules produced with SNMS showed the highest anthocyanin retention after storage in the water activity (aw) range of 0.11-0.94 at 40 °C.

14.
Plant Foods Hum Nutr ; 72(3): 243-249, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28744719

RESUMEN

Resistant starch type IV (RSIV) can be produced by chemical modifications (etherized or esterified) such as conversion, substitution, or cross-linking, which can prevent its digestion by blocking enzyme access and forming atypical linkages. In this research, the effects of barrel temperature (145.86-174.14 °C), the screw speed (42.93-57.07 Hz) and derivatization (esterification) in the formation of RSIV content of directly expanded snacks (second generation snacks) were studied. Potato starch was chemically modified by phosphorylation and succinylation, and expanded by using the extrusion cooking process. Snacks with phosphorylated starch showed expansion index from 2.57 to 3.23, bulk density from 306.19 to 479.00 kg/m3 and RSIV from 43.27 to 55.81%. Snacks with succinylated starch had expansion index from 3.52 to 3.82, bulk density from 99.85 to 134.51 kg/m3 and RSIV from 23.17 to 35.01%. The results found in this work showed that it is possible to manufacture extruded directly expanded snacks (second-generation snacks) such as a ready-to-eat (RTE) with good physicochemical properties and without substantial loss of extrusion functionality, which could bring a healthy benefit due to the presence of RSIV.


Asunto(s)
Manipulación de Alimentos/métodos , Solanum tuberosum/química , Almidón/química , Culinaria , Fosforilación , Bocadillos , Temperatura
15.
J Food Sci ; 81(9): E2224-32, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27550869

RESUMEN

Starch edible films (EFs) have been widely studied due to their potential in food preservation; however, their application is limited because of their poor mechanical and barrier properties. Because of that, the aim of this work was to use the extrusion technology (Ex T) as a pretreatment of casting technique to change the starch structure in order to obtain EFs with improved physicochemical properties. To this, corn starch and a mixture of plasticizers (sorbitol and glycerol, in different ratios) were processed in a twin screw extruder to generate the starch modification and subsequently casting technique was used for EFs formation. The best conditions of the Ex T and plasticizers concentration were obtained using response surface methodology. All the response variables evaluated, were affected significatively by the Plasticizers Ratio (Sorbitol:Glycerol) (PR (S:G)) and Extrusion Temperature (ET), while the Screw Speed (SS) did not show significant effect on any of these variables. The optimization study showed that the appropriate conditions to obtain EFs with the best mechanical and barrier properties were ET = 89 °C, SS = 66 rpm and PR (S:G) = 79.7:20.3. Once the best conditions were obtained, the optimal treatment was characterized according to its microstructural properties (X-ray diffraction, Scanning Electron Microscopy and Atomic Force Microscopy) to determine the damage caused in the starch during Ex T and casting technique. In conclusion, with the combination of Ex T and casting technique were obtained EFs with greater breaking strength and deformation, as well as lower water vapor permeability than those reported in the literature.


Asunto(s)
Embalaje de Alimentos/métodos , Conservación de Alimentos/métodos , Polímeros/análisis , Almidón/química , Zea mays/química , Glicerol/química , Humanos , Microscopía Electrónica de Rastreo , Permeabilidad , Plastificantes/química , Sorbitol/química , Vapor , Temperatura , Agua/química , Difracción de Rayos X
16.
Interciencia ; Interciencia;34(4): 252-258, abr. 2009. ilus, graf, tab
Artículo en Español | LILACS | ID: lil-630816

RESUMEN

Harina de sorgo contaminada con aflatoxinas (AFB1+AFB2) a una concentración total de 140µg·kg-1, fue sometida a extrusión termoplástica usando un perfil de temperatura de 60-80-100ºC. El contenido de humedad (CH) de la harina fue ajustado a 20, 25 y 30% mediante la adición de diferentes cantidades de ácido cítrico (AC) acuoso a concentraciones de 0; 0,5; 1; 2; 4 y 8N. El perfil de temperatura, en combinación con el CH y la concentración de AC, afectaron significativamente la cantidad de aflatoxinas recuperadas en los extrudidos; el máximo porcentaje de eliminación fue de 35,5%. En los extrudidos procesados con altos CH y concentraciones de AC se encontraron los valores más altos en la diferencia de color (DE), así como los valores más bajos en viscosidad. Los índices de expansión fueron favorecidos a mayores CH y altas concentraciones de AC. Los mayores valores de fuerza al corte se encontraron en los extrudidos elaborados con un mayor CH; sin embargo, no se presentaron diferencias significativas para las diferentes concentraciones de AC evaluadas. Empleando condiciones moderadas durante la extrusión en combinación con altas concentraciones de AC se obtuvieron extrudidos con aceptable pH, color, viscosidad, así como con buenas propiedades funcionales y texturales.


Sorghum flour contaminated by aflatoxin at a concentration of 140µg·kg-1 was extrusion-cooked in a single screw extruder with a temperature profile of 60-80-100°C. The moisture content (MC) of the flour was adjusted to 20, 25 and 30% by adding aqueous citric acid (CA) at concentrations of 0, 0.5, 1, 2, 4 and 8N. The temperature profile in combination with the MC and CA concentrations significantly affected the extent of aflatoxin reduction in the extruded sorghum; the maximum percentage of aflatoxin reduction was 35.5%. In extruded sorghum prepared with high MC and CA concentrations, the highest values in color difference (DE) and smallest values of viscosity were found. The expansion index was favored by higher MC and CA concentrations. The highest cutting force values were found in extruded products prepared with a higher MC, but there were no significant differences between those values and the different CA concentrations evaluated. Using moderate extrusion conditions in combination with higher concentrations of CA, products were obtained with acceptable pH, color, viscosity, as well as with good textural and functional properties.


Farinha de sorgo contaminada com aflatoxinas (AFB1+AFB2) na concentração total de 140µg·kg-1, foi submetida ao proceso de extrusão termoplástica usando um perfil de temperatura de 60-80-100ºC. O conteúdo de umidade (CH) da farinha foi ajustado a 20, 25 e 30% mediante a adição de diferentes quantidades de ácido cítrico (AC) aquoso em concentrações de 0; 0,5; 1; 2; 4 e 8N. O perfil de temperatura, combinado com o CH e a concentração de AC, afetaram significativamente a quantidade de aflatoxinas recuperadas nos extrudidos; a máxima porcentagem de eliminação foi de 35,5%. Nos extrudidos procesados com alto CH e concentração de AC se encontraram os valores mais altos na diferença de cor (DE), assim como os valores mais baixos em viscosidade. Os índices de expansão foram favorecidos a maior CH e altas concentrações de AC. Os maiores valores de força ao corte se encontraram nos extrudidos elaborados com maior CH; no entanto, não se apresentaram diferenças significativas para as diferentes concentrações de AC avaliadas. Utilizando condiciones moderadas durante a extrusão em combinação com altas concentrações de AC se obtiveram extrudidos com aceitável pH, cor, viscosidade, assim como com boas propriedades funcionais e texturais.

17.
Arch. latinoam. nutr ; Arch. latinoam. nutr;50(4): 366-373, dic. 2000. tab, graf
Artículo en Español | LILACS | ID: lil-305288

RESUMEN

En el presente trabajo se evaluó un proceso de cocimiento dieléctrico de maíz integral para la elaboración de harinas instantáneas para preparación de frituras de masa y tortillas. Durante el proceso de elaboración de harinas instantáneas la menor variación en color se observó en las muestras adicionadas con cal. La mayor capacidad de absorción de agua correspondió a las muestras procesadas sin cal. La cohesión y adhesión de masas de harinas instantáneas preparadas con cal por cocimiento dieléctrico se sitúan dentro de los valores reportados para muestras de masa de nixtamal y de harinas comerciales de maíz nixtamalizado. El análisis de color en frituras elaboradas con harinas instántaneas preparadas con cocimiento dieléctrico mostraron ligeros cambios con relación a las frituras elaboradas por el proceso tradicional de nixtamalización. Las frituras de tortilla preparadas con harinas instantáneas (adicionadas de cal) con 15 minutos de cocimiento dieléctrico, presentaron valores de delta E similares al control. El contenido de humedad de las frituras varió en un rango de 1.5 a 2.8. Las frituras de masa de harinas instantáneas preparadas por cocimiento dieléctrico adicionadas de cal absorvieron la mayor cantidad de aceite, seguidas por el control y finalmente por las muestras de frituras de tortilla. Las frituras de tortilla preparadas con harinas instantáneas (adicionadas de cal) durante 10 y 15 minutos con cocimiento dieléctrico fueron crujientes y suaves. Las harinas instantáneas elaboradas por cocimiento dieléctrico de maíz integral presentan un alto potencial para producir frituras de buenas características funcionales con ahorros substanciales en gasto de agua, tiempos de procesamiento y mayores rendimientos debido al uso integral del grano de maíz


Asunto(s)
Grasas , Harina , Alimentos , Zea mays , Ciencias de la Nutrición , México
18.
J Sci Food Agric ; 80(6): 657-664, 2000 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29345796

RESUMEN

Three commercial nixtamalised Mexican maize flours (CNMFs) designated HI-A, HI-B and HI-C were evaluated in this work. For each brand, four samples corresponding to four consecutive months of production were evaluated. Tortillas prepared by the traditional process of nixtamalisation were used as the control. The maize flours and their respective tortillas showed variations between samples in their physical, chemical and rheological parameters. The three commercial maize flours incorporated additives and preservatives. The moisture content, colour, pH, subjective water absorption capacity, water solubility index, water absorption index and swelling capacity of flours showed strong differences between the three CNMFs with respect to the chemical analysis. Important differences in the protein, calcium and amylose contents were observed. Tortillas from CNMFs had a blander maize flavour, less desirable texture and staled more rapidly than traditional tortillas. Some modifications are required in the current Official Mexican Quality Standard, principally in the appropriate selection of additives and levels used in the preparation of CNMFs. © 2000 Society of Chemical Industry.

19.
Arch. latinoam. nutr ; Arch. latinoam. nutr;47(2): 136-40, jun. 1997. tab
Artículo en Español | LILACS | ID: lil-217607

RESUMEN

Este estudio tuvo por objetivo la evaluación de los efectos de germinación sobre la calidad nutricional en dos variedades comerciales de sorgo bajo en taninos: sorgo rojo sin testa (ICSY-LM 89513) y sorgo blanco (ISIAO Dorado). Después de 24 horas de germinación la concentración de taninos condensados (equivalentes de catequina) se redujo en 60 por ciento y 40 por ciento para el sorgo rojo y blanco respectivamente. Sin embargo los niveles de taninos se incrementaron a 100 por ciento a las 96 horas de germinación. La concentración de ácido fítico disminuyó cerca del 90 por ciento a las 96 horas para ambas variedades. El contenido de lisina se incrementó en 110 por ciento (72 horas de germinación) y 129 por ciento (48 horas) para el sorgo blanco y rojo respectivamente. Los contenidos de tiamina, niacina y riboflavina se incrementaron en 73,200 y 353 por ciento respectivamente para el sorgo rojo a las 72 h. de germinación y 15,44 y 93 por ciento respectivamente para el sorgo blanco a las 48 horas de germinación. La digestibilidad enzimática "in vitro" se incrementó a las 72 h. en 39.3 por ciento para el sorgo blanco. La concentración de albúminas fue incrementada a las 72 horas en 80 por ciento y 74 por ciento para el sorgo rojo y blanco respectivamente. La Relación de Eficiencia Proteica Calculada indica mejorías nutricionales con la germinación, resultando este proceso un método práctico y sencillo que prevee mejores propiedades nutricionales a las semillas de sorgo para ser usado como alimento humano


Asunto(s)
Grano Comestible/clasificación , Germinación/fisiología , Producción de Alimentos/economía , Proteínas/análisis , Semillas/clasificación
20.
Arch. latinoam. nutr ; Arch. latinoam. nutr;46(4): 315-9, dic. 1996. ilus, tab
Artículo en Español | LILACS | ID: lil-217595

RESUMEN

Se evaluaron los cambios ocurridos en algunos componentes químicos de carácter nutricional (proteína, fibra dietaria total, vitaminas hidrosolubles, lisina, triptofano estracto etéreo y ácidos grasos), de tortillas preparadas con harina integral obtenidas por un experimental de extrusión contínua (proceso CINVESTAV) comparadas con tortillas obtenidas por el proceso tradicional de nixtamalización y maíz crudo. El contenido de proteína de las tortillas obtenidas por los procesos de extrusión y tradicional, fue similar al de maíz crudo; sin embargo, en las tortillas de nixtamal se observó el menor valor de este componenete. Los contenidos de fibra dietaria total y lisina disponible de las tortillas experimentales obtenidas por extrusión mostraron mayores valores (p<0,05) en relación a las tortillas del proceso tradicional. Las tortillas de ambos procesos presentaron pérdidas de vitaminas hidrosolubles, con respecto a sus respectivos maíces sin procesar. La disminución de los niveles de proteína, triptófano y vitamina en las tortillas tradicionales de nixtamal con respecto al maíz crudo, es atribuida a la pérdida de pericarpio, capas de aleurona y otras partículas solubles durante el proceso. El tratamiento térmico en ambos procesos (tradicional y CINVESTAV) disminuyó el contenido de extracto etéreo y ácidos grasos. Las tortillas obtenidas por el proceso de extrusión CINVESTAV, presentaron mejores características nutricionales en los componentes evaluados que las obtenidas por el proceso tradicional de nixtamalización


Asunto(s)
Humanos , Masculino , Femenino , Harina/análisis , Harina/estadística & datos numéricos , Zea mays , Ciencias de la Nutrición
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