Abstract Isolated rice starch (NS), was subjected to chemical and thermomechanical modification with (MHS) and without (MS) previous hydrolysis for the evaluation of the main starch properties such as degree of substitution (DS), color, water absorption and solubility index (WAI, WSI), viscosity, texture, thermal properties (differential scanning calorimetry DSC) and structural properties (infrared-IR, Xray-Rx analysis, and relative crystallinity index-ICR). The DS obtained in both starches was within the range allowed by the FDA for its safety use as food ingredient (0.01-0.2). The modification showed an increase in WAI and WSI values, being WAI value higher in MS (4.80) and WSI value higher in MHS (32.06). The viscosity of retrogradation showed a significant decrease (P<0.05) in MHS (0.013) and MS (5.613), however, the hardness of starch gels decreased (60 %) while the adhesiveness decreased only in MS (66 %). The ICR in MHS and MS increased with regard to the NS. The presence of the acetyl group in the starch molecule was observed in the signals between 1650 to 1744 cm-1 confirming the esterification. The starches showed a high potential for its application as edible coatings and as wall material for microencapsulation.

Resumen Almidón de arroz aislado (AN), fue sometido a modificación química y termomecánica con hidrólisis previa (AMH) y sin hidrólisis previa (AM), para ser caracterizado en grado de sustitución (GS), color, índice de absorción y solubilidad en agua (IAA e ISA), así como sus propiedades reológicas (viscosidad, textura), térmicas (Calorimetría diferencial de barrido - DSC) y estructurales (Infrarrojo- IR, rayos X-Rx e índice de cristalinidad relativa-ICR). El GS obtenido en ambos almidones se encontró dentro del rango permitido por la FDA (0.01-0.2) siendo seguro como ingrediente alimenticio. La modificación mostró un incremento en IAA e ISA, obteniéndose el mayor valor de IAA en el AM (4.80) y de ISA en el AMH (32.06). La viscosidad de retrogradación presentó una disminución significativa (P<0.05) en AMH (0.013) y AM (5.613), asi mismo la dureza de los geles de almidón decreció (60 %) mientras que la adhesividad disminuyó únicamente en AM (66 %). El ICR en AMH y AM aumentó con respecto al AN. La presencia del grupo acetilo en la molécula de almidón se observó en las señales entre 1650-1744 cm-1, confirmando la esterificación. Los almidones evaluados presentan alto potencial para su uso como recubrimientos comestibles y como materiales de pared para microencapsulación.

Abstract Natural starch (NS) was isolated from triticale flour (TF) and later modified by extrusion (MS) using acetic anhydride as a reactive agent. From each product (NS, TF, MS) a proximal analysis was performed as well as the characterization of its physicochemical properties (particle size determination (PSD), water absorption index (WAI) and solubility index (WSI), color L*, a*, b*, and viscosity), degree of substitution (DS), and thermal properties (differential scanning calorimetry (DSC). Particle below sizes of 250 μm were obtained in the NS and MS treatments (42.91 and 36.03 %, respectively). The DS value (0.1) was found within the range allowed by the FDA for human consumption (0.01-0.2). MS presented a greater value in WAI (4.52), and the color parameter of b* (22.75) as well as a decrement in L* (70.61) and retrogradation viscosity (5.2 cP) values, being an indicator of greater functionality compared to NS. Through DSC, we found that MS experimented a decrement of 30.2 °C in the glass transition temperature compared with NS. Through isolation and the different modification treatments applied to triticale starch, we obtained functional ingredients with high potential, for use in food for microwave expanded and fried food as third generation snacks.

Resumen A partir de harina de triticale (HT) se aisló almidón (AN) para ser modificado por extrusión (AM), utilizando como agente reactivo anhídrido acético. De cada uno de los productos (HT, AN, AM) se realizó su análisis proximal y se caracterizaron sus propiedades fisicoquímicas (determinación de tamaño de partícula (DTP), índice de absorción de agua (IAA) e índice de solubilidad en agua (ISA), color L*, a*, b* y viscosidad), grado de sustitución (GS), y propiedades térmicas (calorimetría diferencial de barrido (CDB). Se obtuvieron tamaños de partícula en los tratamientos AN y AM por debajo de los 250 µm (42.91 % y 36.03 %, respectivamente). El valor del GS (0.1) se encontró dentro del rango permitido por la FDA para consumo humano (0.01-0.2). AM presentó mayores valores del IAA (4.52), así como del parámetro de color b* (22.75) y un decremento en los valores de L* (70.61) y de viscosidad de retrogradación (5.2 cP), siendo un indicador de una mayor funcionalidad en comparación con AN. Mediante CDB se encontró que el AM experimentó un decremento de 30.2°C en la temperatura de transición vítrea en comparación con la AN. A través del aislamiento y la modificación del almidón de triticale se obtuvieron ingredientes funcionales con un alto potencial para ser utilizadas en alimentos destinados a expansión en microondas o por freído como las botanas de tercera generación.

AbstractEffects of different β-glucan concentrations in maize flour on the properties of frozen maize tortillas were evaluated. Masa (dough), pre-cooked (PTs), frozen (FTs), thawed (TTs), and cooked tortillas (CTs) were made and analyzed. Moisture content of masa and tortillas significantly decreased as β-glucan concentration increased; however, the water absorption capacity (WAC), ice melting enthalpy, and frozen water in FTs increased. Texture and color of the masa, PTs, and CTs as well as sensory analysis showed differences only between tortillas with 0% and 4% β-glucans. β-glucans did not affect the texture of CTs. Soluble fiber increased by over threefold and fivefold in tortillas with 2% and 4% β-glucans, respectively, than in those without β-glucans. This result was consistent with the observed structural changes in tortillas, showing an increase in high-fiber aggregates with increasing β-glucan concentration. Tortillas with 2% β-glucans showed acceptable physicochemical, functional, and sensory properties, but over three times the soluble fiber. Therefore, it is possible to obtain frozen tortillas with high fiber content and increase their shelf life for subsequent cooking while maintaining good properties.

Gelatin-based films containing soy lecithin or Yucca schidigera extract and glycerol as plasticizer were produced by casting and characterized for their mechanical properties, water vapor permeability (WVP), water solubility, opacity and morphology. The addition of glycerol reduced the tensile strength, with a difference of ~ 68% between the values for the minimum and maximum concentrations evaluated, both for the plasticizer and the surfactant. Elongation values reached 52% and 40%, for films containing yucca extract and lecithin, respectively, when higher amounts of plasticizer and surfactant were added. Lower values of WVP were obtained when the intermediate concentration of glycerol (20 g plasticizer/100 g protein) was used, reaching 0.14 and 0.15 g mm/m² h kPa, respectively, for films containing yucca extract and lecithin. The solubility was not affected by adding plasticizer and / or surfactants. The morphologies of the inner sections of the films, regardless of type of surfactant used, were compact, without pores or phase separation, indicating efficient incorporation of the compounds added to the protein matrix.

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.