AbstractThis study analyzed the addition of huitlacoche paste (HP) in baked tortilla chips (TC), evaluating its effects on functional, physicochemical and structural changes during processing. Two blue corn grains were nixtamalized, stone milled, air dried and milled to obtain flour; commercial blue corn flour (TM1) and commercial TC (TM2) were used as controls. Additions of 0, 3, 6 and 9% of HP were formulated; masas were prepared at 55% moisture content (MC), precooked and baked in an industrial machine. TC crispiness was influenced by grain characteristics and percentage of HP. Huitlacoche paste addition caused an increase in total dietary fiber (from 5.27 to 14.54%), total soluble phenolics content (from 17.52 to 37.60 mg GAE/100 g) and antioxidant capacity (from 6.74 to 7.98 μmol TE/g) in TC. Results suggest that tortilla chips added with huitlacoche can be an alternative to prepare this traditional edible fungus and produce healthier snacks, not fried and enriched with bioactive compounds.

This research aimed to develop tortilla chips (TC) high in antioxidants from extruded and nixtamalized blue corn flours prepared with calcium hydroxide Ca(OH)2 and calcium lactate C6H10O6Ca. Tortilla chips were made with extruded flours [0.1% Ca(OH)2; 0.9% C6H10O6Ca; without calcium] and nixtamalized flours [1% Ca(OH)2; 2.95% C6H10O6Ca] using the frying process. Total anthocyanin, total phenolics content, antioxidant activity, color, texture, and oil content were determined. The color of tortilla chips from extruded flours (TCEF) showed high values of the parameters a* and b* indicating a reduction in the blue color. These color parameters were significantly different from those observed in tortilla chips from nixtamalized flours (TCNF), which tended to be more blue. The TCEF retained 15% anthocyanins, 34% phenolics, and 54% antioxidant activity. Pearson's correlation analysis indicated that anthocyanins and phenolics correlated significantly with antioxidant activity and color. TCEF with both calcium sources showed higher fracturability compared with that of TCNF. Oil absorption showed an opposite effect, with lower oil content in TCEF. Nixtamalization and extrusion with C6H10O6Ca resulted in flours and TC high in anthocyanins and antioxidant activity, representing an alternative production process for corn snack high in antioxidants.

Starch derivatives of taro (Colocasia esculenta L. Schott) and rice were characterized as wall materials of orange oil (d-limonene) by spray drying. Native starches were initially hydrolyzed with HCl and then esterified. Succinylated starches were modified using a conventional method in a slurry and were extruded; whereas, the phosphorylated starches were modified using the extrusion process. Viscosity and solubility of starches reduced after acid hydrolysis, derivatization, and extrusion. The particle size of the wall materials ranged between 20.05 and 31.81 µm. The encapsulation efficiency of the phosphorylated taro, rice, and waxy corn starches was 96.9, 96.8 and 97.1% respectively, and 98.6, 98.1, and 98.8% for succynilated taro, rice, and waxy corn starches, respectively. Starch derivatives of taro and rice could potentially be used as wall materials of orange oil d-limonene.

Neste trabalho foram elaborados pellets expandidos a partir da mistura de 50% de Amido de Batata (AB), 35% de Milho de Qualidade Protéica (MQP) e 15% de Farelo de Soja (FS), utilizando extrusor de laboratório com matriz de 1,5 × 20,0 × 100,0 mm. As variáveis independentes analisadas foram: Temperatura de Extrusão (TE) (75-140 °C) e Umidade da Mistura (UM) (16-30%). O efeito das variáveis de extrusão foram estudadas quanto ao Índice de Expansão (IE), a densidade aparente (DA), força de penetração (FP), Energia Mecânica Específica (EME), perfil de viscosidade, DSC, cristalinidade através de difração de raio X e Microscopia Eletrônica de Varredura (MEV). A PF diminuiu de 30 para 4 kgf com o aumento de ambas as variáveis independentes (TE e UM). EME foi afetada somente pela UM, diminuindo com o aumento desta variável. A região otimizada mostrou que os melhores resultados foram obtidos utilizando TE na faixa de 123-140 °C e 27-31% UM, respectivamente. Pellets expandidos com características aceitáveis foram obtidos usando a mistura de amido de batata, milho de qualidade protéica e farelo de soja através de extrusão termoplástica.

A blend of 50% Potato Starch (PS), 35% Quality Protein Maize (QPM), and 15% Soybean Meal (SM) were used in the preparation of expanded pellets utilizing a laboratory extruder with a 1.5 × 20.0 × 100.0 mm die-nozzle. The independent variables analyzed were Barrel Temperature (BT) (75-140 °C) and Feed Moisture (FM) (16-30%). The effect of extrusion variables was investigated in terms of Expansion Index (EI), apparent density (ApD), Penetration Force (PF) and Specific Mechanical Energy (SME), viscosity profiles, DSC, crystallinity by X-ray diffraction, and Scanning Electronic Microscopy (SEM). The PF decreased from 30 to 4 kgf with the increase of both independent variables (BT and FM). SME was affected only by FM, and decreased with the increase in this variable. The optimal region showed that the maximum EI was found for BT in the range of 123-140 °C and 27-31% for FM, respectively. The extruded pellets obtained from the optimal processing region were probably not completely degraded, as shown in the structural characterization. Acceptable expanded pellets could be produced using a blend of PS, QPM, and SM by extrusion cooking.

Misturas de fibra do bagaço da cana-de-açúcar, amido de milho e concentrado proteico de soro de leite foram extrusadas. Neste estudo, foi utilizado extrusor monorrosca, utilizando parafuso com taxa de compressão de 1:1 e matriz de 3 mm de diâmetro. As melhores condições de processamento foram determinadas de acordo com um delineamento central composto rotacional (α = 1,41) com 5 pontos centrais, totalizando 13 tratamentos. Durante o processo de extrusão, o teor de fibra insolúvel foi diminuído e o teor de fibra solúvel aumentado. Com o aumento dos teores de fibra das misturas e da temperatura de extrusão, ocorreu a diminuição do índice de expansão e o aumento do índice de absorção de água; entretanto, para as misturas com teores intermediários de fibra, os efeitos nestes parâmetros foram contrários. Teores elevados de fibra das misturas aumentaram a força de penetração e diminuíramo índice de luminosidade, a solubilidade em água e a força de adesividade dos géis. O processo de extrusão melhorou as propriedades funcionais da fibra do bagaço de cana de açúcar, possibilitando sua adição em sistemas alimentares diversos.

Blends of fiber from sugar cane bagasse, corn starch, and whey protein concentrate were extruded. A single screw extruder, equipped with a screw at a constant compression ratio of 1:1 and a die diameter of 3 mm, was used. The best processing conditions were determined according to a central composite rotatable design (α = 1.41) with 5 central points, which gives a total of 13 tests. During the extrusion process the content of insoluble fiber decreased and that of soluble fiber increased. An increase in the contents of fiber and in the barrel temperature resulted in a decrease in the expansion index values and an increase in the water absorption index values; whereas in blends with intermediate fiber contents the effects in these parameters were found to be the opposite. High fiber contents increased penetration force but decreased luminosity, water solubility index values and the adhesive force in gels. The extrusion process improved the functional properties of sugarcane fiber bagasse enabling its addition to diverse alimentary systems.

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.

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 instantáneas 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 DE 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 absorbieron 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 con 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.

Application of dielectric cooking to produce instant maize flour for corn and tortilla chips. This present work reports on the evaluation of a method for producing of instant flour for corn and tortilla chips based on dielectric cooking (DC). The samples prepared with lime showed a smaller variation in color than those without lime. A greater water absorption capacity was found in the samples processed without lime. The values for cohesion and adhesion of the DC masa prepared with lime are within the range of values previously reported for samples of masa prepared with nixtamal and commercial instant maize flours. The color analyses of chips from DC masa showed slight changes in relation to the chips prepared by the traditional process of nixtamalization. The DC tortilla chips (plus lime) with 15 minutes of DC showed similar values of DE as compared to the control (commercial tortilla chips). The moisture of the DC chips varied in the range from 1.5 to 2.8. The DC tortilla chips with lime absorbed a lower amount of oil than the control sample and the corn chips. In fact, the DC chips absorbed lower amount of oil as compared to the control. The DC tortilla chips with lime and processed for 10 and 15 minutes were crunchy and smooth. Dielectric cooking displays a high potential for corn and tortilla chips with good functional characteristics, giving substantial savings of water, processing time and with higher yields due to the use of the whole grain.