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

Valenzuela, José Manuel (coord.) (2015) Juvenicidio. Ayotzinapa y las vidas precarias en América Latina y España. México: NED/ Instituto Tecnológico y de Estudios Superiores de Occidente/El Colegio de la Frontera Norte.

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Portadilla e Índice del Número 235 de la RMCPS

Osmotic dehydration, similar to classical dehydration, allows partial concentration of cellular material in food. However, instead of using heat, the water activity of the product is reduced by placing the same in contact with a hypertonic solution of solutes. As a result of this process, perishable fruits are transformed into products with good storage conditions, with greater stability, similar quality to the raw material and often better in color, flavor and aroma than the products of more sophisticated technologies. The objective of this study was to evaluate the influence of this process on Sugraone seedless grapes, comparing some physical parameters. The fruits were evaluated in natura and after the osmotic dehydration process. For the dehydration process, the grapes were immersed in sucrose syrup with a concentration of 60 ° Brix and kept under osmosis at 40 ° C for 24 hours in a B-type chamber. The physical parameters evaluated were determined in triplicate, being: individual and specific real mass, volume, mutually perpendicular diameters, projection area of rest position, eccentricity and surface area, volume by mass displacement and by geometric similarity, circularity and sphericity . It was observed that the grapes presented an excellent response to the dehydration process, being the process indicated for this variety.

The high perishability of the onion may limit the shelf life of the bulbs, mainly by the biochemical transformations. The objective of this work is to determine and compare polyphenoloxidase activity (PPO) in yellow and purple onions and their functional body. The raw material was purchased in the local market , where they were transported to the Food Analysis Laboratory of the, Center for Agro-Food Science and Technology, Federal University of Campina Grande, Campus Pombal, being selected, cleaned, sorted, peeled processed and carried out chemical and physico- chemical analysis and determination of the enzymatic activity of polyphenol oxidase (PPO). The statistical design was completely randomized with two treatments (purple and yellow onion) with six repetitions. The purple onion presented levels of soluble solids, flavonoids and anthocyanins, more significant than the white onion. Both onions showed enzymatic activity, without significant differences.

Often found in some Brazilian biomas as caatinga, brejo, restinga and cerrado, the velame, Croton heliotropiifolius Kunth, is popularly known for its medicinal properties used in stomach ache, gastric reflux, vomiting, bloody diarrhea and to reduce fever. In addition to the pharmacological properties, its essential oil has larvicidal activity against Aedes aegypti, as well as the ethanol extract showed significant insecticidal activity against Sitophilus zeamais. This study aimed at evaluating the toxicity of preliminary methanolic extract of Croton heliotropiifolius Kunth on Artemia salina larvae. The bioassay was carried out at concentrations of 50 µg/ml, 100 µg/ml, 250 µg/ml, 500 µg/ml, 750 µg/ml, 1000 µg/ml of methanolic extract of leaves. The extract studied showed a moderate toxicity to Artemia salina, with LC 50 values in the range of 637,29 µg/mL.

Agroecology emerged as a set of scientific and traditional knowledge that aims to make the transition from the conventional agriculture model to sustainable production systems. This new way of thinking about agroecosystems is a way to guarantee healthy food with social inclusion, recovery of traditional values and valuation of family production and environmental conservation, however, it requires a phase of transition. Thus it was analyzed the main motivations and limitations of the producers of the Cachoeira settlement in the construction of the agroecological transition process in the city of Itapura, São Paulo. The study was a qualitative research divided into two stages, in the first one it was applied a semi-structured questionnaire for reality diagnose and in the second stage a meeting with the methodology of the storm type of ideas to survey the motivations and limitations for the agroecological transition in the settlement. The study allowed us to understand that, despite not meeting the prerequisites understood as necessary for the agroecological transition process, families have sought to build, based on their reality and with their resources, new strategies to build a process of change to achieve autonomy, improving the environment and quality of life.

The objective of this work was to evaluate alternative substrates in the quality of seedlings and in the productivity of chicory in organic cultivation. The experiment conducted in two phases: plant nursery and field, in June 2016. The experimental field is located at Seridó Ecological farm, in Rio Branco, Acre. The experimental design was a randomized block with five treatments and four replications. The treatments constituted by the Golden commercial substrate used as control and by four other alternative substrates: soil (30%), organic compound (30%); Soil conditioner (30%), coal (10%), natural thermophosphate (1.5 kg m-3), dolomitic limestone (1.0 kg m-3) and potassium sulphate (1.0 kg m-3). What differentiated them was the substitution of the conditioner: Carbonized rice husk; Coconut fiber; Fiber of the stem of ouricurí palm (Attalea phalerata) or Cork decomposed of kapok (Ceiba pentandra). The cultivar used was Sugar loaf. At 22 days after sowing, the seedlings evaluated to obtain the quality index and at 60 days after transplanting to the field the total fresh mass, commercial, total dry, commercial and total and commercial productivity were evaluated. The substrates containing kapok and coconut fiber had better performance for root dry mass and Dickson quality index in the seedlings phase, total fresh mass, total and commercial dry mass and total field productivity.

The intense evaporation, drainage deficiency and inadequate use of fertilizers have increased problems with salinity, causing losses in crop yields. It was aimed to evaluate the yield and quality of muskmelon plants due to the priming of seed and levels of water salinity. The experiment was conducted in split type 4 x 2 plots allocated in a randomized block design with four replications. The plot consisted of 4 irrigation water salinity levels (0.3, 1.0, 1.7 and 2.4 dS m-1) and sub plots of plants from seed treated and not treated with saline NaCl. It was evaluated the characteristics related to production and quality of melon fruit. The cultivar used was the Rangers of the Cantaloupe group planted in the spacing of 2.0 x 0.4 m. The priming of the seeds NaCl solution affected the melon yield components in the fruit mass was higher in plants originated from seeds treated with NaCl. In the formation of productivity, she became apparent the fruit mass contributed more than the number of fruit per plant and this difference was significant only under low water salinity of 0.3 dS m-1. The quality of the melon fruit was not affected by seed priming with NaCl and plants irrigated with saline water of 2.4 dS m-1 reduced their production and fruit quality of melon.

The temperature oscillation, provoked by the climatic changes, has been affecting the agriculture in several points of agricultural areas, with that, it is necessary to carry out studies on the adaptability of the crops to a wide range of temperature. Thus, the objective of the study was to verify the efficiency of the germination and initial establishment of chilli pepper seedlings submitted to sub and supra optimal temperatures. The experiment was conducted in a completely randomized experimental design, in a factorial scheme consisting of one species and three temperatures (15 ° C, 25 ° C and 35 ° C). The seeds were submitted to germination tests, under a photoperiod of 12 hours for 14 days, together with first germination count, germination speed index, seedling length, total dry mass, electrical conductivity, respiratory activity and imbibition curve under the temperatures of 15, 25 and 35 °C. The temperature of 25 ° C presented superiority to the other treatments in all variables tested. At temperatures of 15 and 35 ° C, germination was completely inhibited. Tests such as those performed in the present study are efficient for the determination of seed viability in different temperature ranges.