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.

High energy ball milling and sonofragmentation were used successfully to reduce the crystallite size of calcium carbonate extracted from the eggshell. The ceramic was milled using either deionized water or stearic acid and then subjected to a subsequent size reduction by means of a tip horn. The thermal degradation of particles was influenced by the presence of stearic acid in milling process because it acts as a protective layer around eggshell particles. It was found that the reduction in crystallite size diminishes the degradation temperature and the presence of the surfactant may lead to a change in particle shape by trough a superplasticity phenomenon. Tubes, fibers and a rectangular prism were observed in Transmission Electron Microscopy.

Abstract Over five million tons of chicken feathers (CF) are generated all over the world by the poultry industry, with an immense potential to exploit. Keratin is an abundant protein found in chicken feathers that offers excellent thermal properties and it is durable, insoluble in organic solvents and chemically unreactive. Elastomers are materials with a wide application range, for instance, adhesives, shoe soles, plastic modifiers, tire industry, sealants, among others. However, it is necessary to improve their properties and mechanical performance at elevated temperatures. A good path to do so is to combine the elastomer with CF to obtain materials with enhanced properties. In present work, a composite based on styrene-butadiene (SB) elastomer and CF was prepared by means of melt mixing. Composites were characterized by FTIR, DSC, DMA and X ray diffraction techniques. The results show that there is an increase in stiffness of SB/CF composites compared with pure elastomer.