Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The best co-digestion ratio between mezcal vinasses and bovine manure was investigated to produce methane.Five vinasses and bovine manure mixtures in different proportionswere compared (v/v): 25-75, 50-50, 75-25, 100-0, and 0-100, with six replications. As reactors, 496 mL glasscontainers with hermetic seal were used, with 300 mL of active volume under mesophilic conditions (36 ± 1 oC) for 10 days. The pH, total solids, and volatile solids of vinasses,bovine manure, and their mixtures were determined in triplicate.The methane accumulated volume was greater with the 0-100 and 75-25, followed by the 100-0, with 286.23, 286.40, and 225.48 NmL CH4, respectively. Methane yield was higher with 100-0 and 75-25 with 28.27 and 22.77 NmL CH4 g-1volatile solids, respectively. The Gompertz bacterial growthmodel showed that the micro-organisms adaptation periodin vinasses was longer than in bovine manure. Co-digestionof vinasses and bovine manure in proportion 75-25 % improvedthe methane production by 26.7 % with respect to the digestion of vinasses alone, and reduced the adaptation timeof bacteria to vinasses by 4.12 days.

In order to describe the effects of origin (Mexico and United States of America), sex, age at slaughter (AS, 4categories), body condition score (BCS, 5 categories) and slaughter weight (SW, 4 categories) on carcass characteristics of culled quarter horses, data from 235 horses sacrificed in the same slaughter facility within a 150 days period wereanalyzed. Overall, 74.5% were from the US, 80% were < 15 years of age and had BCS ≤ 4, and sex proportion was similar(51.5% female vs 48.5% males). Horses from USA had heavierSW (27%), leg circumference (4%), carcass weight (4.2%) and carcass yield (2.9%). Sex did not affect any characteristics evaluated. Horses from 3 to 8 years had greater rib eye area(REA) and backfat thickness. Except for leg length, as BCS and SW improved, all carcass characteristics linearly increased as BCS and SW increased. It is concluded that origin, sex, and age, explained very little on the carcass characteristics. The slaughter weight mainly explained changes in linear measures,carcass weight, and compact index, while BCS mainly explained carcass yield and REA.

The genus Beauveria comprises a cosmopolitan teleomorphic and anamorphic group of ento-mopathogenic fungi. The aim of this study was to characterize a new isolate of Beauveria spp. and compare it to the LBB-1 commercial strain. The isolate was collected from the ant Atta insularis and adults of the coffee borer, respectively. It was cultivated on solid SDAY medium enriched with 1% yeast extract. The biological effectiveness of the isolate was determined on C. formicarius. DNA was isolated using the CTAB method and an internal transcribed spacer (ITS1, ITS4) were used as primers for amplification. The consensus sequence obtained was deposited in GenBank (MK246940) and used for phylogenetic analysis. This isolate showed differences in morphological characteristics; however, it showed low genetic variability regarding worldwide isolates of B. bassiana. Concerning its biological effectiveness, the isolate demonstrated to be virulent on the phytophagous adults, producing 50% mortality. Four clades were identified and the polytomous topography recovered for clade 1 indicates high genetic similarity (99-96%) with Beauveria bassiana from several countries. The morphological and molecular characterization made it possible to accurately identify the new isolate as Beauveria bassiana. The identified specie is another possibility for integrated pest management in Cuba and Mexico.

Mastitis is an infectious disease of cows. The presence of mastitis is due to various factors such as the geographical area, climate, periods of drought, nutrition, hygiene, among others. The objective of this study was to determine the prevalence of subclinical mastitis in dual-purpose cattle under grazing conditions, through the microbiological status of milk and its association with serum levels of vitamins E and A during the summer in ranches neighbouring the rural community of Cobachi, Sonora. Five hundred four milk samples were collected from the four quarters of 126 cows, for microbiological culture and to evaluate catalase, coagulase, and oxidase tests. The isolates were tested for antimicrobial sensitivity by the Kirby-Bauer method (disk-diffusion on agar). Vitamin A and E were analyzed by HPLC chromatography. Serum values of vitamin A and E, 5.58 and 0.59 µmol/L respectively, were found lower than normal and did not correlate with mastitis. Mastitis prevalence was 65.80%, and Gram-positive species in clusters, as well as coagulase and catalase-positive and oxidase negative, suggests that is gender Staphylococcus sp. Furthermore, ceftriaxone was an antibiotic that shows more resistance. A high prevalence of subclinical mastitis not associated with vitamins and deficiencies of vitamins E and A was found in summer is concluded.

The present study aimed to find a mixture of BHT and quercetin with an antioxidant synergism that would enable both compounds to be used at low concentrations and, subsequently, evaluate the preservative action of the combination selected on ground beef patties stored at 4 ºC. Our results showed that quercetin possessed a higher antioxidant activity than BHT, and of the five combinations tested, a 1:5 BHT-quercetin combination presented a synergistic antioxidant activity. For the refrigerated beef patties, the 1:5 combination (5.2 and 26.0 mg/kg of BHT and quercetin, respectively) produced a beneficial action on the redness, yellowness, antioxidant capacity, metmyoglobin content, and thiobarbituric acid reactive substance value, which was similar to that produced by 100 or 36 mg/kg of BHT or quercetin (P >0.05, except the redness induced by quercetin). These benefits were compared with the data obtained from a preservative-free patty control sample (P <0.001 to <0.05). Our study shows, for the first time, that the use of a 1:5 BHT-quercetin combination was an effective, simple, and available method to preserve refrigerated beef patties, which can substitute the individual addition of high concentrations of these compounds by the meat industry.

The effect of L-cysteine on the solubility, protein structure, rheological and textural characteristics of corn masas were investigated.  Masa was prepared with L-cysteine at two levels (0.25, 0.50 %). Size exclusion chromatography and Fourier transform infrared spectroscopy were utilized for protein characterization. Dynamic rheology and textural profile analysis were carried out on masas. There was a significant difference in relative solubility between the control and masas containing L-cysteine.  Treatments with L-cysteine increased the relative solubility of proteins. Determination of FT-IR revealed that addition of L-cysteine did not affects secondary structure of protein.  Data also showed significant differences in textural properties. Masas con L-cysteine improved the springiness, adhesiveness and cohesiveness.  This investigation  reveal that L-cysteine, may improve the elasticity or storage moduli, important characteristics of masas.

In most cases, the current strategies to treat swine effluents in Mexico are not efficient, resulting in the discharge of partially treated wastewater, wasting an energy resource. This study aimed to evaluate the impact of the solid-liquid separation of swine wastewater on methane production using granular (GS) and disperse sludge (DS), under three concentrations. The COD concentration in the raw effluent (RE) was 13,640 mg/L, which corresponds up to 69 % to the solid fraction (SF) and the remaining to the liquid fraction (LF). The results indicate that the cultures with the SF produced the higher cumulative methane, increasing 1.47-, 1.31-, and 1.22-times in retaliation to the RE, at 3, 6, and 9 g VSS/L of DS. The solid-liquid separation strategy resulted in a higher methane production, evidenced by the amount of methane obtained by the SF and LF, which was 2.14- and 2.28-times higher than the obtained by the RE. The application of anaerobic processes to treat solid and liquid wastes will allow to recovery efficiently the energy from the transformation of organic matter into methane.

Ethanol content in fermented wort is the most important parameter for whisky production in terms of volume of distillate per unit of malt. Ethanol biosynthesis during wort fermentation depends on many factors; however, the initial concentration of fermentable carbohydrates significantly affects the final content of ethanol in fermented wort. The objective of this study was to evaluate the effect of different mashing and fermentation conditions on ethanol content in fermented wort, and to determine the conditions that better contribute to the increase of this compound. It was observed that an isothermal mashing of 65 ºC for 3 h, with a 1:3 grist:water ratio, results in worts with high fermentable carbohydrates content. In addition, it was determined that the higher ethanol yield is attained with closed fermenters at 20 ºC and12.5 ºP worts. These conditions result in a conversion efficiency of 0.34 g of ethanol/g of soluble solids, in fermented worts with reduced amounts of methanol and glycerol.  

The production of habanero pepper in Yucatán demands quality seedlings at the time of transplantation, which has led to the use of growth regulators, which, although it is true, potentiate the germination and development of the plants, they also increase production costs. For this reason, production alternatives are being sought that reduce costs, which is why an eye has been focused on Aloe vera gel, whose chemical composition reports the presence of phytohormones such as gibberellins and salicylic acid. To study the response of the aloe gel in the emergence and development of the root and shoot in habanero pepper seedlings, 500 seeds of the habanero pepper variety "Mayapan" were sown, in groups of 100, previously soaked in 100 mL of aloe gel. at 0, 2.5, 5, 10 and 20%, for 24 h. The results obtained show that Aloe vera gel reduces emergence by four days and favors root development, plant height and total fresh biomass by up to 18%; 11% the diameter of the stem and 13% number of leaves, observing a greater effect with the 5% solution of Aloe vera gel.

Sports supplements are a category of dietary supplements which in recent years has not only increased their quantity and availability, but also the number of new products. Athletes of all levels are interested in consuming supplements which are useful to increase gains in muscle mass thus making the consumption of these products a common practice. Unfortunately, there are some products that are actually doping substances which are offered as sports supplements, on the other hand, certain sports supplements may contain active pharmaceutical ingredients or their analogues undeclared in their ingredients, probably to effectively enhance the benefits that these products ensure exposing consumers to a significant potential health risk, especially those unfamiliar with sports nutrition products. It is important for health professionals to be aware of the possible implications for the consumption of certain products offered in the sports nutrition market when evaluating their patients for a variety of pathologies.