Desenvolvimento e validação de testes de fluxo lateral para a detecção de cultivares geneticamente modificados e de aflatoxinas em produtos agrícolas

The expansion of cultivated areas with genetically modified crops (GM) is a worldwide phenomenon, stimulating regulatory authorities to implement strict procedures to monitor and verify the presence of GM varieties in agricultural crops. With the constant growing of plant cultivating areas all over the world, consumption of aflatoxin-contaminated food also increased. Aflatoxins correspond to a class of highly toxic contaminants found in agricultural products that can have harmful effects on human and animal health. Therefore, the safety and quality evaluation of agricultural products are important issues for consumers. Lateral flow tests (strip tests) is a promising method for the detection both proteins expressed in GM crops and aflatoxins-contaminated food samples. The advantages of this technique include its simplicity, rapidity and cost-effective when compared to the conventional methods. In this study, two novel and sensitive strip tests assay were developed for the identification of: (i) Cry1Ac and Cry8Ka5 proteins expressed in GM cotton crops and; (ii) aflatoxins from agricultural products. The first strip test was developed using a sandwhich format, while the second one was developed using a competitive format. Gold colloidal nanoparticles were used as detector reagent when coated with monoclonal antibodies. An anti-species specific antibody was sprayed at the nitrocellulose membrane to be used as a control line. To validate the first strip test, GM (Bollgard I® e Planta 50- EMBRAPA) and non-GM cotton leaf (Cooker 312) were used. The results showed that the strip containing antibodies for the identification of Cry1Ac and Cry8Ka5 proteins was capable of correctly distinguishing between GM samples (positive result) and non-GM samples (negative result), in a high sensitivity manner. To validate the second strip test, artificially contaminated soybean with Aspergillus flavus (aflatoxin-producing fungus) was employed. Food samples, such as milk and soybean, were also evaluated for the presence of aflatoxins. The strip test was capable to distinguish between samples with and without aflatoxins samples, at a sensitivity concentration of 0,5 μg/Kg. Therefore, these results suggest that the strip tests developed in this study can be a potential tool as a rapid and cost-effective method for detection of insect resistant GM crops expressing Cry1Ac and Cry8Ka5 and aflatoxins from food samples.

Desenvolvimento e validação de testes de fluxo lateral para a detecção de cultivares geneticamente modificados e de aflatoxinas em produtos agrícolas

The expansion of cultivated areas with genetically modified crops (GM) is a worldwide phenomenon, stimulating regulatory authorities to implement strict procedures to monitor and verify the presence of GM varieties in agricultural crops. With the constant growing of plant cultivating areas all over the world, consumption of aflatoxin-contaminated food also increased. Aflatoxins correspond to a class of highly toxic contaminants found in agricultural products that can have harmful effects on human and animal health. Therefore, the safety and quality evaluation of agricultural products are important issues for consumers. Lateral flow tests (strip tests) is a promising method for the detection both proteins expressed in GM crops and aflatoxins-contaminated food samples. The advantages of this technique include its simplicity, rapidity and cost-effective when compared to the conventional methods. In this study, two novel and sensitive strip tests assay were developed for the identification of: (i) Cry1Ac and Cry8Ka5 proteins expressed in GM cotton crops and; (ii) aflatoxins from agricultural products. The first strip test was developed using a sandwhich format, while the second one was developed using a competitive format. Gold colloidal nanoparticles were used as detector reagent when coated with monoclonal antibodies. An anti-species specific antibody was sprayed at the nitrocellulose membrane to be used as a control line. To validate the first strip test, GM (Bollgard I® e Planta 50- EMBRAPA) and non-GM cotton leaf (Cooker 312) were used. The results showed that the strip containing antibodies for the identification of Cry1Ac and Cry8Ka5 proteins was capable of correctly distinguishing between GM samples (positive result) and non-GM samples (negative result), in a high sensitivity manner. To validate the second strip test, artificially contaminated soybean with Aspergillus flavus (aflatoxin-producing fungus) was employed. Food samples, such as milk and soybean, were also evaluated for the presence of aflatoxins. The strip test was capable to distinguish between samples with and without aflatoxins samples, at a sensitivity concentration of 0,5 μg/Kg. Therefore, these results suggest that the strip tests developed in this study can be a potential tool as a rapid and cost-effective method for detection of insect resistant GM crops expressing Cry1Ac and Cry8Ka5 and aflatoxins from food samples.

Associativismo nos municípios rurais: uma alternativa de desenvolvimento local em Portalegre/RN

This work aims to study the associations as mediating the process of social change and its importance for local development. The hypothesis is that associations, but bring dynamism to the smaller cities and improve the living conditions of their members, relegated to the background social sustainability, understood this as a permanent exercise of mobilization and participation in community life. The assumptions of the study are that the practice group has influenced the processes of local development in Brazilian rural municipalities through the mediation of government programs and projects aimed at combating rural poverty require social organization for their achievement. The concept of local development in this work was rescued from studies of political economy and sociology. But the concepts of collective action and partnerships advêem studies of political participation and social development of the theory of alternative or solidarity. The party consisted of an empirical case study conducted with four associations of farmers in the municipality of Portalegre-RN. Why choose qualitative study was used the technique of semi-structured interviews with the chairmen I members of associations and other actors considered essential to understanding the study (religious leaders, local political power and chairman of the union of rural workers), a total of 20 interviews, in addition to the observations of field and documentary research in records of the.ir own organizations. The survey results show that the performance of groups of farmers are key components and determinants for the production I marketing of agricultural products and for boosting the economy, as well as security for minimum levels of citizenship. Yet we are still in a space purpose of social change, which comes to confirm the initial hypothesis of this work

Determinação da composição química de quatro variedades de feijão caupi (Vigna unguiculata L. Walp) cultivadas em solo potiguar

The cowpea (Vigna unguiculata L. Walp) is a major food crops in northeastern Brazil. In Rio Grande do Norte, the cowpea, vigna beans or cowpea, as it is known, has great socioeconomic importance as a source of nutrients in food, with great emphasis among agricultural products. To improve productivity and resistance to pests, two cultivars were developed exclusively by EMPARN (Agricultural Research Corporation of Rio Grande do Norte), for breeding. The samples were provided by EMPARN, two improved (Potiguar and Laugh year) and two landraces (Rib of beef and Canapu). The seeds were ground and made into flour samples and the determination of moisture and ash by graviméticos methods, lipids by Soxhlet extraction, fibers with determiner fiber, carbohydrates by difference and minerals by ICP-OES were performed except the match analyzed by UVvis. The results showed a high fiber content (55.55% and 55.32% and 50.04% improved samples and 50.32% creole samples) and protein (25.52% and 25.27% improved and 27 samples, 23% and 24.99% creole samples). Comparing the results of the mineral content, the improved cultivars stood out in relation to Ca, Co, P, Mg, Mo and Na. Creole cultivars showed better results for Cu, Cr (low), Fe, Mn, Ni, K and Zn. The results will be important in future nutritional research and to build a table of Brazilian chemical composition of foods.

Caracterização físico-química e química do fruto do juazeiro (Ziziphus joazeiro Mart) e avaliação da sua conservação por fermentação láctica

Considering the plant biodiversity in the Brazilian Northeast, whose components can be inserted into sustainable production systems, the jujube (Ziziphus joazeiro Mart.) emerges as to recovery of its fruit. The present study has as objective to characterize the fruit of the jujube under the physical, physicochemical and chemical approach and assess its conservation by spontaneous lactic fermentation under the influence of chloride, sodium, calcium and potassium. According to the legislation, vegetable acidified by fermentation that is subjected to lactic acid fermentation in order to achieve a final product pH less than or equal to 4.5. The results of the physical, chemical and physico-chemistry of ripe fruit jujube showed the potential of this species for agro-processing. The yield of edible portion (91.83%), soluble solids content (18,98º Brix), titratable acidity (0.14% citric acid), pH (5.30) and its composition, divided in moisture (79.01%), protein (2.01%), lipids (0.52%), carbohydrate (17.59%), fiber, ash (0.76%) and its minerals were consistent with the characteristic profile fruits, thus favoring the development of spontaneous lactic fermentation. The minimum pH and titratable acidity observed maximum in the fermentation process under the influence of mixtures of salts (NaCl and KCl NaCl2) values ranged from 3.4 to 3.7 and from 0.54 to 0.95 (% lactic acid), respectively. The profile of the lactic fermentation of fruit of jujube in brine, fermented microbiological quality and the result of analysis of primary sensory prepared preserved, the application of endorsed by the consumer sensory evaluation, more particularly, derived from fermented fruit preserved in the presence of chloride sodium, in accordance with the traditional techniques of lactic fermentation of vegetables. The results of sensory evaluation conducted with 100 consumers (tasters) revealed an acceptance rate equal to 78% of the preserve. Despite restrictions on the sensory acceptability of fermented under the influence of salts (KCl and CaCl2) substitutes sodium chloride, preserved these perspectives presented to balance the optimization of mixtures, health product safety and consumer awareness towards prefer a more healthy product with reduced sodium content.