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.

Abstract The effects of ultrasound-assisted extraction (UAE) at different ultrasound power densities (UPDs; 40, 80, and 120 mW/mL) and solid:liquid (S:L) ratio (1:2, 1:3, and 1:6) on the extraction of carbohydrates from Agave tequilana plant of different ages were evaluated. Extracts obtained (6- and 7-year-old plant) were analyzed in the yield of carbohydrates (YC), fructan (FRU) content, simple sugars, fructan profile and the average degree of polymerization (DPn). UPD, S:L ratio, and plant age all affected YC, FRU, and DPn. Maximum YC and FRU were obtained from the older agave with UPD and S:L ratio of 120 mW/mL and 1:6, respectively; while glucose, fructose, and sucrose were highly released from the younger plant. Agave of 7-year-old presented the highest DPn. Fructan degradation occurred at high UPD, increasing the simple sugars and decreasing the DPn. Thermal-traditional extraction without sonication caused more fructan degradation; and overall, ultrasound enhanced fructan extraction and minimized fructan damage, representing a technological alternative for fructan extraction from agave.

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.

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.