Carmen Durán-de-Bazúa

Composition, phase behavior and thermal stability of natural edible fat from rambutan (Nephelium lappaceum L.) seed.

In this paper, the chemical composition, the main physicochemical properties, phase behavior and thermal stability of rambutan (Nephelium lappaceum L.) seed fat were studied. These results showed that the almond-like decorticated seed represents 6.1% of the wet weight fruit and is: 1.22% ash, 7.80% protein, 11.6% crude fiber, 46% carbohydrates, and 33.4% fat (d.b.). The main fatty acids in the drupe fat were 40.3% oleic, 34.5% arachidic, 6.1% palmitic, 7.1% stearic, 6.3% gondoic, and 2.9% behenic; the refraction, saponification and iodine values were 1.468, 186, and 47.0, respectively. The phase behavior analysis showed relatively simple crystallization and melting profiles: crystallization showed three well-differentiated groups of triglycerides around maximum peaks at +30.8, +15.6 and -18.1 degrees C; the fat-melting curve had a range between -14.5 and +51.8 degrees C with a fusion enthalpy of 124.3 J/g. The thermal stability analyzed in an inert atmosphere of N(2) and in a normal oxidizing atmosphere, showed that in the latter, fat decomposition begins at 237.3 degrees C and concludes at 529 degrees C, with three stages of decomposition. According to these results, rambutan seed fat has physicochemical and thermal characteristics that may become interesting for specific applications in several segments of the food industry.

Biomonitoring of wastewaters in treatment plants using ciliates

The aim of this project has been to study and compare the ciliate populations present in roptating biological reactors treating three different wastewaters. Wastewaters chosen were a maize mill (nejayote), a sugarcane/ethyl alcohol plant (vinasses) and a recycled paper mill (whitewaters). The initial dissolved organic contents, measured as soluble chemical oxygen demand (COD) and biochemical oxygen demand in five days (BOD5), were 2040±150 mg COD L−1 and 585±5 mg BOD5L−1 for nejayote; 2000±20 mg COD L−1 and 640±5 mg BOD5 L−1 for vinasses and 960±200 mg COD L−1 and 120±10 mg BOD5 L−1 for whitewaters. Results obtained indicate that ciliated protozoa proliferated in the different chambers of each rotating biological reactor (RBR). Saprobity indices, as a quantitative evaluation parameter, indicate that there are no universal species of ciliates associated with specific BOD5 concentrations. Therefore, the number of species of ciliates present in the effluent indicate qualitatively the efficiency of removal of pollution from the wastewaters during treatment in the rotating biological reactors.

Development of a Relative Ranking Risk Index for Risk Assessment in the Transportation of Liquefied Petroleum Gas in Mexico City's Metropolitan Area

ABSTRACT The development of a relative ranking methodology created specifically for the assessment of the risk due transportation of Liquefied Petroleum Gas (LPG) in Mexico City is reported. Mexico City has a number of conditions that present specific challenges: Large population, varied geography, large consumption of LPG, and all sorts of vehicles, including those for LPG. Given Mexicos status as “emerging economy,” it is reasonable to assume that the main causes that promote accidents during transportation of LPG are quite different from those in developed countries. This issue was corroborated through information from official sources and from news media. Due to the lack of official data, a systematic collection of information on the media was performed. A relative ranking methodology was developed based on a systematic study to elucidate the main causes of accidents in Mexico and on the results derived from the integrated database from official data and the media. The weighting that made up the Risk Index for Transportation of LPG is based on the same database. A classification guide was created in order to harmonize criteria in the assessment of the parameters of the proposed risk index.

Temperature effects on ciliates diversity and abundance in a rotating biological reactor

Experiments in a 20-litre, laboratory, rotating biological reactor were performed at 10, 20, and 30°C to depurate carbonaceous wastewaters coming from the food industry with an organic load of 2 g of Chemical Oxygen Demand (COD) per litre (0·6 g of Biochemical Oxygen Demand (BOD5) per litre). Twenty acrylic discs, 0·3 m diameter were arranged in 10 compartments, and rotated at 30 rpm. At a one-day residence time, when pseudo-steady-state conditions were reached, removal of organics was, at 10°C, 45 and 63% for COD and BOD5, respectively; at 20°C, 49 and 84%; and for 30°C, 87 and 96%. Microbial communities proliferating at these temperatures corroborated previous studies on the relationship between the degree of pollution and the type of microorganisms present in the different stages of the reactor.

Artificial wetlands performance: nitrogen removal

Artificial wetlands (AW) are a promising option for wastewater treatment in small communities due to their high performance in nutrients removal and low operation and maintenance costs. Nitrogen can favour the growth of algae in water bodies causing eutrophication when present at high concentrations. Nitrogen can be removed through different mechanisms (e.g. nitrification-denitrification, adsorption and plant uptake). Environmental conditions such as temperature and relative humidity can play an important role in the performance of these systems by promoting the growth of macrophytes such as reeds and cattails (e.g. Phragmites australis, Typha latifolia respectively). In this paper, two AW systems were compared, one located in Mexico City, Mexico at an altitude higher than 2,000 m above the sea level, and the second one located in Villahermosa, Tabasco, Mexico at an a altitude near the sea level (27 m). Both systems comprised five reactors (147-L plastic boxes) filled with volcanic slag and gravel and intermittently fed with synthetic water. The removal nitrogen efficiency found for the system located in Mexico City was higher than that of the Tabasco system (90 and 80% as TKN respectively). The higher temperatures in the Tabasco system did not enhanced the nitrogen removal as expected.

Effects on Body Mass of Laboratory Rats after Ingestion of Drinking Water with Sucrose, Fructose, Aspartame, and Sucralose Additives~!2009-03-31~!2010-11-25~!2010-08-26~!

The excessive consumption of natural sweeteners is considered to be a major cause of increase in body mass. The authors wished to establish whether hypocaloric artificial sweeteners also promoted mass gain in laboratory rats (Harlan Wistar male rats). Ad libitum sweeteners were added to the drinking water of five groups of nine male rats each weighing circa 40g: Group 1, 15% fructose; group 2, 10% sucrose; group 3, 0.3% aspartame; group 4, 0.19% sucralose; and group 5 (control), ordinary drinking water. The daily volume of water consumption, the amount of ingested food, and gain of body mass were assessed during 73 days. Histological sections of the liver tissue of these rats were analyzed using Sudan and Hematoxylin-Eosin red staining. Results indicated that the fructose solution promoted the highest final gain in body mass, statistically different from the control and sucrose groups (p<0.05). The caloric consumption was similar to that of the sucrose group, but different from that of the control and one of the groups consuming hypocaloric sweeteners, aspartame (p<0.05). Rats that ingested sucrose solutions had the lowest final body mass in spite of the fact that their total caloric intake was one of the highest, and as mentioned, similar to fructose. Rats that drank water with hypo-caloric artificial sweeteners, aspartame and sucralose ingested the same amount of food, and the caloric intake was similar to the control group (p<0.05). They were fatter than the control and sucrose groups, although their caloric consumption was lower than that of the fructose-drinking specimens, apparently confirming recent findings about glucose absorption with ingestion of artificial sweeteners. The behavior of the sucralose group, with a body mass higher than those of the control and sucrose groups, should be further studied, since this group showed a tendency to drink more water over time when compared to the control and aspartame groups. Liver-to-body mass ratios were not statistically different (p<0.05) among the five groups, but both groups consuming hypocaloric sweeteners had slightly lower ratios than the sucrose, fructose, and control groups. As has been mentioned in previous research, ingestion of fructose solutions led to an increase of lipids in the liver tissue, in comparison with the other groups studied. Groups consuming hypocaloric sweeteners also showed a slight increase in lipid accumulation in liver tissue but not as much as the fructose-consuming group. The results of these experiments indicate the advisability of a long term experiment focusing on the ingestion of these sweeteners and their role in the increase in body mass.

Energy and Activated Carbon Production from Crop Biomass Byproducts

The proposed research is designed to upgrade sugarcane biomass byproducts (bagasse) to high-grade fuel (hydrogen), activated carbon, and chemical feedstocks (synthesized gas). It is shown how gasification can significantly enhance the value of sugarcane through the production of energy, synthesis gas, and carbon, which is required in the sugar purification and decoloring process. Furthermore, it can act as a valuable associate to sugar fermentation processes used to produce ethanol employed as a substitute for hydrocarbon fuels and raw materials. Through this project one can make the large sugarcane-growing regions of Mexico and other Latin American, African, and Asian countries more economically diverse and self-sufficient, increasing local employment and enabling support of larger rural populations. A key part of the proposed research is the training of highly skilled professionals to guide the Mexican sugarcane agro-industry toward production of high added value products in addition to sugar.

ESTUDIO DE LOS PROTOZOARIOS CILIADOS PARA DETERMINAR LA CALIDAD DEPURATIVA DE SISTEMAS ROTATORIOS BIOLÓGICOS PARA TRATAMIENTO DE AGUAS RESIDUALES

Los metodos tradicionales de tratamiento biologico de aguas residuales involucran comunidades aerobias para la etapa secundaria de tratamiento. Para obtener el articulo completo pueden contactar al Editor de la Revista Ecosistemas y Recursos Agropecuarios en el siguiente correo electronico era@ujat.mx y se les enviara sin algun costo.

Oleous Extraction of Carotenoids from Shrimp Cephalothorax and its Effect on a Microencapsulated Diet with Nauplii Larvae

ABSTRACT Carotenoids were oil extracted from shrimp-cephalothorax meal at two meal:oil ratios (1:5 and 1:10) and two meal-particle sizes (0.150 and 0.150–0.177 mm). Extraction results were significant at 0.150 mm in particle size and a meal:oil ratio of 1:10, obtaining 286 mgL−1 of pigments. Pigmented oil was microencapsulated to reduce deterioration by spray drying using two encapsulating blends: Mesquite gum-whey-protein concentrate and Arabic gum-mesquite gum-maltodextrin 10 DE. Microcapsule morphology and thermo-oxidative stability were evaluated. The Arabic/mesquite gum blend showed the best morphology and stability. A bioassay using Litopenaeus vannamei nauplii was performed using microalgae as a control. Results indicated that pigmented oil microcapsules increased the survival percentage when compared with the control. Larvae growth evaluated as the exoskeleton length was significantly different from the control favoring the pigmented oil diet. Larvae behavior measured as DI and PLIc showed no significant differences among the two treatments and the control.