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Mexico is the main exporter of mango fruits and prickly pears, so new postharvest techniques to increase shelf life are studied. Thermal treatments on both fruits can affect their cuticle so it was reviewed. When mango latex remains within the fruits, it avoids sap burn and decreases anthracnose and stem end rot infestation, so two systems were developed to minimize latex de-sapping. A gripper cuts stems 0.5 cm long and cauterizes them with a hot knife implement. A heating gun applied paraffin wax to mangoes without the stem end and protected them better against anthracnose lesions. Physicochemical analysis of several mango varieties was carried out after harvesting, at market place and after pedicel cutting and cauterizing. Keitt mangoes showed the lower quantity of total soluble solids (TSSs) and total acidity (TA). When the pedicel was cauterized, TSS dropped. Two grippers were developed to cryo-cauterize prickly pears as this system is more energy-efficient than hot cauterization. A six-finger gripper moved over a pneumatic actuator toward a dry ice chamber to optimize pear cryo-cauterization. Gripper’s strong grasping damaged the fruits due to excessive compression. TSS and TA of cryo-cauterized fruit remained constant during the three months of fruit storage.

ResumenUn sistema fotovoltaico (SFV) puede proporcionar energía a usuarios que habitan en zonas donde no hay red de servicio público. El presente trabajo presenta una metodología que permite determinar la distancia mínima y el consumo mínimo de la energía en función de la distancia de la red eléctrica existente que justifica el uso de SFV´s comparando los precios por construcción y conexión de la red de Energía Eléctrica de Comisión Federal de Electricidad (CFE) en función de la distancia de construcción y los costos de instalación de sistemas fotovoltaicos para invernaderos con gastos de energía hasta de 30 kWh calculados con el programa desarrollado por el posgrado IAUIA de la UACh. Existen diferentes tarifas de energía eléctrica, las cuales aumentan anualmente de 4.4 hasta 27 %, estas se analizaron para los años 2003 -2013 y se proyectaron hasta el año 2038. Se comprobó que calculando los gastos eléctricos con las tarifas 9M establecidas en el sector agrícola y para 10 y 15 años de uso de SFV es viable instalarlos aun en lugares donde ya existe la red eléctrica de CFE para la energía consumida mayor de 4.8 y 1.5 kWh por día en invernaderos correspondientemente, ya que solo los gastos por consumo energético durante estos años rebasan los costos de instalación de SFV. Se determinó el consumo mínimo de energía en función de la distancia de existencia de la red eléctrica que justifica la instalación de los SFV. AbstractA photovoltaic system (SFV) can provide power to users who live in areas where no public service network. This paper presents a methodology to determine the minimum distance and minimum energy consumption depending on the distance from the existing electrical grid that justifies the use of SFV's comparing prices for construction and network connection Electric Power Federal Electricity Commission (CFE) as a function of distance from construction and installation costs of photovoltaic systems for greenhouses with energy costs up to 30 kWh calculated with the program developed by the IAUIA graduate UACh. There are different electricity rates, which increase annually from 4.4 to 27%, these were analysed for the years 2003 to 2013 and projected to 2038. It was found that calculating electrical costs with 9M rates established in the agricultural sector and 10 and 15 years of using SFV is feasible to install even in places where there is already CFE's power grid for most energy consumed 4.8 and 1.5 kWh per day in greenhouses correspondingly, as only energy expenses during these years beyond installation costs SFV. Minimum power consumption in function of the distance of the grid existence of justifying the installation of SFV was determined.

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