The aim of the current study was to establish the in vitro prebiotic effect of cacao flour (Threobroma cacao) on the growth of probiotic thermotolerant lactic acid bacteria in a meat batters. Cacao flour was added to meat batters inoculated with P. pentosaceous, in order to establish its effect on lactic acid bacteria viability, as well as its effect on oxidative rancidity, instrumental color, texture and lactic acid bacteria (in situ) growth during 15 days of storage at 4 °C . The in vitro growth of lactic acid bacteria using cacao flour as carbon source was acceptable compared with the growth obtained using glucose. Oxidative rancidity was diminished in cacao flour samples. The color of the samples was less bright and red, but more yellow. The addition of cacao flour produced a less hard and more cohesive texture, with no changes in elasticity parameters. Lactic acid bacteria counts increased during storage, having a groth promoting effect. Therefore, the use of this kind of bacteria in cooked meat products lead to a foodstuff with high nutritional or symbiotic value that enhance microbial intestinal flora due to its intake.

50 % of animal fat (pork lard) was replaced with pumpkin seed butter mixed with inulin, starch or without any of these ingredients, in order to establish the effect on physicochemical properties, instrumental color and meat batter textures. Moisture, yield, expressible moisture, cooking stability of the different treatments, as well as fat total and fat released were established. Instrumental color was established in Lab coordinates. Textural differences were observed performing a textural profile analysis. Cooked meat batters yield was improve by a partial replacement of animal fat with pumpkin seed butter, but water could not be physically or chemically retained in the meat systems. Pumpkin seed butter with starch released more fat after re-heating the product despite its low fat content. Pumpkin seed butter changed meat batters color, becoming darker and yellow. The texture of the pumpkin seed butter with inulin or starch were less hard and cohesive compared with pork lard samples. In order to improve yield and moisture, it is suggested to replace animal fat with pumpkin seed butter mixed with inulin, producing less hard and cohesive samples. Pumpkin seed butter is a functional ingredient that improves nutritional properties of this kind of foodstuffs.

Infiltration process is influenced by soil and vegetation management practices in areas of grasslands. In the state of Zacatecas, Mexico, native grass¬lands take up over 70 % of the surface. One of the main problems is the loss of soil cover caused by overgrazing. Three treatments were applied in order to assess the impact of different infiltration managements: a) exclusion of grazing (E), b): exclusion + aerator roller (E+R), and c): continuous grazing (PC) in two sites of medium open grassland: Viboritas and Benito Juarez, Zacatecas, Mexico. Infiltration rate was obtained using a rain simulator type Asseline. Results showed that both sites the average of infiltration rate of treatment PC (27.0 mm•h-1) were not significantly different (P≤0.01) to the infiltration rate of treatment E (32.6 mm•h-1) and E+ R (30.3 mm•h-1).

Intensity-duration-frequency (IDF) equations of rainfall have applications in the design of urban drainage works and are also used in the estimation of flows in small rural watersheds. In the present work rainfall IDF equations were created and compared based on pluviometer and pluviograph information recorded on the weather station of Chapingo during the period of 1975-2005. The methodology of creating IDF equation based on pluviograph consisted of: a) obtaining heights of rainfalls in millimeters of the studied area, for the durations of 5, 10, 15, 20, 30, 40, 60 min and for 2, 3, 4, 5, 10, 15 and 24 h, b) transforming heights to intensities, c) obtaining return periods for each intensity, and d) obtaining multiple linear regression equations. The methodology of creating IDF equation based on pluviometer was similar to the pluviograph, however the difference were the empirical relations, using as a main data the duration 24 h rainfall, the intensities for the durations of 5, 10, 15, 20, 30, 40, 60 min and for 2, 3, 4, 5, 10, 15 and 24 h were obtained, each one for different return periods. In this last step, the methodology of pluviometer carried out important errors related to the data obtained with pluviograph; however in many parts of Mexico only pluviometric information is available. A statistical comparison between both methods was performed and it was observed that IDF rainfall equation obtained with pluviometric underestimate the real IDF equation obtained with pluviograph; this error increases with the return period of the rainfall intensity

Hybrid energy systems are an excellent solution for electrification of remote rural areas where grid extension is not easy and expensive. Such sys¬tem incorporates a combination of one or several renewable energy sources such as solar photovoltaic, wind energy, micro-hydro and conventional generators for backup. The present paper discusses different system components of hybrid energy system and develops a general model to find an optimal combination of energy components for a typical rural community, minimizing capital cost, net present value and cost of energy. The simula¬tion study and the optimization of hybrid energy system are based on a computer program known as HOGA, as simulation tool. From the economic analysis, the different types of system configuration were established. Optimal operation has a unit cost of 0.23 € kW 1 h 1 with the selected hybrid energy system, being 100 % renewable energy contribution, finishing with the need of a conventional diesel generator. Results from the study will be useful to help decision making and to choose the most appropriate system for the communities