Abstract:The larvicidal activity of essential oils cinnamon (Cinnamomum verum J. Presl), Mexican lime (Citrus aurantifolia Swingle) cumin (Cuminum cyminum Linnaeus), clove (Syzygium aromaticum (L.) Merr. & L.M.Perry), laurel (Laurus nobilis Linnaeus), Mexican oregano (Lippia berlandieri Schauer) and anise (Pimpinella anisum Linnaeus)) and their major components are tested against larvae and pupae of Culex quinquefasciatus Say. Third instar larvae and pupae are used for determination of lethality and mortality. Essential oils with more than 90% mortality after a 30-min treatment are evaluated at different time intervals. Of the essential oils tested, anise and Mexican oregano are effective against larvae, with a median lethal concentration (LC 50 ) of 4.7 and 6.5 µg/mL, respectively. Anise essential oil and t-anethole are effective against pupae, with LC 50 values of 102 and 48.7 µg/mL, respectively. Oregano essential oil and carvacrol also have relevant activities. A kinetic analysis of the larvicidal activity, the oviposition deterrent effect and assays of the effects of the binary mixtures of chemical components are undertaken. Results show that anethole has synergistic effects with other constituents. This same effect is observed for carvacrol and thymol. Limonene shows antagonistic effect with β-pinene. The high larvicidal and pupaecidal activities of essential oils and its components demonstrate that they can be potential substitutes for chemical compounds used in mosquitoes control programs.

This study aimed to obtain a second-generation snack by extrusion from the by-product of rice milling enriched with amaranth. The raw material used was amaranth flour (AF), rice starch (NS) and modified rice starch (MS), which were evaluated by the analysis of substitution degree (SD), differential scanning calorimetry (DSC), viscosity (RVA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The snacks were expanded by extrusion and microwave oven, as a reference method. The samples were evaluated in hardness (D), expansion index (EI), apparent density (DAP), and protein content (P). Afterward, the optimized samples were evaluated by scanning electron microscopy (SEM) and resistant starch (RS). During the thermal characterization, a clear trend in the decrement in gelatinization temperatures was observed (78.35 to 63.90 °C in NS and MS respectively). The curves obtained in RVA analyses showed typical behavior of native (6.35 Pa.s) and extruded starches (2.88 Pa.s), with a significant decrease in viscosity peak. Through the analysis of FT-IR, the introduction of the functional acetyl group (stretching at a wavelength of 1735 cm−1) was corroborated. Snack samples results showed a maximum hardness in MS, with a value of 121 N, and the NS (100%) presented the highest EI value (1.41). The lowest DAP values were obtained for the MS (0.48 g/cm3, 100%) and AF (0.49 g/cm3, 100%) samples. P increased to a higher concentration of AF. In the optimum formulation, the SEM image showed that the expanded microwave sample increased the porosity and obtained an RS value of 8.2%. The formulation obtained in the present study presents high characteristics to be used in the development of a healthy snack.

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.RESUMENA 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.

The effect of high-intensity ultrasound (HIU) on technological and consumer acceptance of whole pork leg sub-primals was evaluated. Sub-primals ('inside', 'knuckle', 'inner shank', 'eye of round' and 'shank off') were processed following standard industrial pork processing for deboned legs in Mexico. They were allocated to one of the three treatments; HIU (22 W/cm 2 and 37 kHz) for 0, 10 or 30 min. Sub-primals were injected (10% w/v NaCl), tumbled and ultrasonicated. After 15 d of freezing storage, sub-primals were thawed following common industrial practice. HIU increased the pH and water-holding capacity and reduced fluid losses after thawing up to 50% (P < 0.05). Meat colour was not affected by HIU, but it significantly reduced shear force (P < 0.001). HIU slightly decreased the consumer preference and acceptance due to a saltier perception. Nevertheless, HIU application offered a clear advantage with positive effects on technological properties of pork for further processing.

Mexican lime bagasse and pomace are rich in pectin and they also represent an important source of valueadded compounds such as polyphenols. Two different options for the combined recovery of pectin and phenolic compounds from Mexican lime bagasse and pomace, two byproducts of industrial lime processing, were developed. Conventional and microwave-assisted extraction methods were used. All pectic extracts presented a degree of esterification in the range of 70%. Pomace extracts had the higher pectin yield and the lower polyphenol content. Among the bioactive compounds identified by HPLC were two flavonones, naringin and hesperidin, all compounds were present in low concentration in the pectic extracts. Microwave pectic extracts presented depolymerization, as observed by molecular weight determination (12 KDa) and compared against conventional pectic extracts which presented a molecular weight of 670 KDa. The film forming capacity of pectic extracts was also evaluated. Antioxidant activity of pectic extracts was also assessed by three different methods; all extracts showed a better activity in Fe 2+ chelating assay (62.85-73.32%) and lipid oxidation inhibition (63.07-72.28%) than in DPPH radical inhibition (5.32-6.65%). These findings indicate a correlation between the amount of phenolic compounds and the antioxidative capacity. Conventional pectic extracts from Mexican lime bagasse and pomace presented bioactive compounds with potential application for edible films and coatings in food industry.