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Arias-Moscoso J.L.,University of Sonora | Soto-Valdez H.,Research Center en Alimentacion | Plascencia-Jatomea M.,University of Sonora | Vidal-Quintanar R.-L.,University of Sonora | And 2 more authors.
Polymer International

Biodegradable films of chitosan with acid-soluble collagen (ASC) isolated from jumbo squid by-products were prepared using solution-mixing and film-casting techniques. The main goal of the study reported was to evaluate the potential application of ASC as an additive in the preparation of biofilms in composites with commercial chitosan (85% deacetylated, viscosity > 400 MPa s and molecular weight of 570.3 kDa). Thermal properties, scanning electron microscopy (SEM) images, mechanical properties, water vapor barrier properties and water solubility of the films obtained were assessed. SEM images revealed that the surface morphology of chitosan films was influenced by the ASC. The ASC led to a structure with a less compact morphology than chitosan films. The incorporation of ASC to chitosan induced an increase in the percentage of elongation at break and a decrease of the elastic modulus of films. However, the addition of ASC to chitosan films had a negative effect on the water barrier properties and increased the solubility. The glass transition temperature of chitosan films was found to be ca 159 °C and shifted to ca 148 °C for ASC/chitosan films containing 50% ASC. ASC from jumbo squid by-products might be useful as a new source of additive in the preparation of biofilms in composites with chitosan. © 2011 Society of Chemical Industry. Source

Abundance patterns for three species of penaeid shrimp off northwestern Mexico are explained based on sampling-catch data obtained by the National Fisheries Institute during closed fishing seasons (1995-2006). The bathymetry and fishing area (>14,000 km2) were determined from a depth dataset of >45,000 points. The catch data were obtained from a sampling network of 62 sites, with an average of 76 trawls per fishing season; the brown shrimp (Farfantepenaeus californiensis) was the most abundant species. The relative abundance models for the three species, produced by two geostatistical methods (inverse distance weighting (IDW) and Kriging), identified mid-northern Sinaloa as the most important area regarding the distribution of the resource, with each species displaying different distribution patterns. The spatial model allowed the categorization of data into three levels of relative abundance, taking the values between quartiles 1 and 3 as the medium abundance and the values below quartile 1 and above quartile 3 as the extremes (low and high). The two geostatistical techniques (IDW and Kriging) produced very similar abundance distribution maps, with values >0.7 of the Kappa index of agreement, particularly for areas of high abundance. These results could be useful to point out those areas that can be used to regulate fishing effort and reduce fishing mortality, supporting the sustainable development of the fishery. Source

Barraza-Guardado R.H.,University of Sonora | Martinez-Cordova L.R.,University of Sonora | Enriquez-Ocana L.F.,University of Sonora | Martinez-Porchas M.,Research Center en Alimentacion | Miranda-Baeza A.,University of Sonora
Ciencias Marinas

The effect of shrimp aquaculture effluents on some environmental parameters of the receiving coastal waters was assessed. Water and sediment samples were taken at different distances from the discharge point (50, 150, and 300 m) when shrimp farms had ceased operations (survey 1), had initiated operations (survey 2), and during the early harvest (survey 3). Water and sediment samples were likewise taken at the same distances from the shore in a non-impacted area. During surveys 1 and 2, the effluents had a negative effect at all three distances (50, 150, and 300 m) on the water quality variables (transparency, seston [total suspended solids, total inorganic solids, particulate organic matter], chlorophyll a, N-NO2–, N-NO3–, N-NH4+), on the sediment quality parameters (organic nitrogen), and on the TRIX index. Contrarily, no differences were observed when the impacted and non-impacted areas were compared during survey 3, probably because the effluents had diminished due to the premature harvesting. The results suggest that at the end of the farming period, the nutrient and organic matter load exceeded the assimilation capacity of the ecosystem, whereas during the recess period, the environment was capable of assimilating the excess organic matter accumulated. The levels reached by the monitored parameters did not exceed the limits established and the impact on the ecosystem is not severe, but they could represent a risk factor in the long term. Additionally, there is evidence that the temporary suspension of shrimp farming operations is beneficial for the environment. © 2014, Universidad Autonoma de Baja California. All rights reserved. Source

Zamudio-Flores P.B.,Research Center en Alimentacion | Tirado-Gallegos J.M.,Research Center en Alimentacion | Monter-Miranda J.G.,Research Center en Alimentacion | Aparicio-Saguilan A.,University of Papaloapan | And 2 more authors.
Revista Mexicana de Ingeniera Quimica

In vitro digestibility of flours and starches from three varieties of oats (Avena sativa L. cv “Cuauhtemoc”, “Teporaca” and “Bachiniva”) grown in the northwestern region (Chihuahua State) of Mexico were evaluated. The physicochemical properties (color evaluation and proximate analysis, quantifying of total and resistant starch and the apparent amylose content) were studied and the thermal properties were determined, pasting, rheological and functional using differential scanning calorimetry, rapid visco-analysis of viscosity, flow curves at steady state, swelling power, solubility and stability to freeze-thawing, respectively. Among the flours and starches no significant difference was observed, however the digestibility was higher in starch, indicating the presence of other compounds which can encourage digestibility, which was confirmed in the proximal and in the determination of electron microscopy analysis sweep. Flour and starch had the highest cv Cuauhtémoc ΔH compared with the flour and starch Bachiniva and Teporaca. The functional properties of freeze-thawing stability increased with increasing number of cycles; however, decreased when the temperature increased. These varieties could find any practical application in various food systems and could be a potential food source for people with eating disorders (v. gr. celiac patients). © 2015, Universidad Autonoma Metropolitana Iztapalapa. All rights reserved. Source

Orellana-Escobedo L.,Research Center en Alimentacion | Garcia-Amezquita L.E.,Research Center en Alimentacion | Olivas G.I.,Research Center en Alimentacion | Ornelas-Paz J.J.,Research Center en Alimentacion | Sepulveda D.R.,Research Center en Alimentacion
CYTA - Journal of Food

Capsaicinoids content and proximate composition of Mexican chili peppers, widely used in the State of Chihuahua, México, were determined. Capsaicinoids content was determined by high-performance liquid chromatography (HPLC) technique. Proximate composition was determined by official AOAC methods. Scoville Heat Units (SHU) were also calculated. Capsaicin content ranged between 22.8 mg/kg and 9097.3 mg/kg dry matter. Dihydrocapsaicin content ranged between 36.8 mg/kg and 4023.6 mg/kg dry matter. Scoville Heat Units ranged between 961 and 211,248. Moisture content was determined with differences (p50.05) among chili pepper types and cultivars ranging from 54.8 g/kg dry matter to 130.1 g/kg dry matter. Ash content (p50.05) ranged from 58.1 g/kg dry matter to 96.1 g/kg dry matter showing statistical differences. Protein content ranged from 120.5 g/kg dry matter to 152.2 g/kg dry matter showing no statistical differences. Fat content (p50.05) ranged from 22.6 g/kg dry matter to 137.6 g/kg dry matter showing statistical differences. Source

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