Selenium (Se) is essential to humans and animals due to its antioxidant properties. Although it is not considered an essential nutrient for higher plants. Many studies show that Se in low concentrations (up to 0.5 mg kg) provides beneficial effects to non-hyperaccumulating plants by participating in antioxidant defense systems and enhancing tolerance to abiotic stress. Therefore, this study aimed to evaluate the effects of Se application rates on rice plants under different soil water conditions. The experiment was conducted on an Oxisol using four Se rates (0, 0.5, 1.0 and 2.0 mg kg) and two soil water conditions (irrigated and water deficit). Selenium application via soil up to 0.5 mg kg increased the plant height, chlorophyll index, sulfur and copper accumulation in shoots, carbon dioxide assimilation, superoxide dismutase (EC 1.15.1.1) activity and decreased the hydrogen peroxide concentration in rice leaves. The accumulation of Se in shoot biomass and Se concentration in seeds increased linearly with the applied rates. Water deficit strongly decreased the plant growth and yield. However, rice plants treated with Se showed higher net photosynthesis, water use efficiency and antioxidant system. This study provides useful information about the roles of Se in protecting rice plants from water deficit stress.

The selenium (Se) is essential for human metabolism, but a large part of the world's population has deficiency in this element. This can be reversed by the consumption of biofortified foods, given that plants can efficiently act in controlling excessive and/or accidental consumption of an element that can occur in humans through the use of dietary supplements. The objective of this study was to evaluate the effect of different application forms and sources of Se in the growth, production, nutrition, physical-chemical characteristics, content and accumulation of Se in carrots. The experiment was conducted under greenhouse conditions, using pots containing 4 dm 3 of Red-yellow Latosol. A completely randomized design was used in a 2x2x2 factorial scheme (with and without Se application, two sources of Se: selenate and selenite, two forms of application of Se: soil and foliar applications), with five replicates. Foliar application of selenate increased the yield and titratable acidity, reducing root ripening index. Foliar application of selenite increased the content of Se in the shoots and the content of carotenoids in the roots. Both sources of Se (selenate and selenite) and application forms (soil or foliar application) increased their content in the roots. However, the foliar application of selenate was the most effective source and form of application. Therefore, it is possible to increase the contents of Se in the edible part of carrots, favoring the consumption of this element by the population. Index terms:Daucus carota Lam; selenate; selenite; maturation index; carotenoids. RESUMOO selênio (Se) é essencial para o metabolismo humano, porém, grande parte da população mundial apresenta deficiência nesse elemento. Isto pode ser revertido pelo consumo de alimentos biofortificados, uma vez que as plantas podem atuar de forma eficiente no controle do consumo excessivo e / ou acidental de um elemento que pode ocorrer nos seres humanos através do uso de suplementos dietéticos. Objetivou-se com o presente estudo avaliar o efeito de formas de aplicação e fontes de Se no crescimento, produção, nutrição, características físico-químicas, teor e acúmulo de Se na cenoura. O experimento foi desenvolvido em casa de vegetação, utilizando vasos com quatro dm 3 contendo Latossolo Vermelho Amarelo. Adotou-se o delineamento inteiramente casualizado, em fatorial 2 x 2 x 2 (com e sem aplicação do Se; duas fontes do Se: selenato e selenito; duas formas de aplicação do Se: via solo e foliar), com cinco repetições. O selenato aplicado via foliar aumenta a produção e a acidez titulável e reduz o índice de maturação das raízes. O selenito via foliar aumenta o teor de Se na parte aérea e o teor de carotenoides nas raízes de cenoura. As duas fontes de Se (selenato e selenito) e formas de aplicação (via solo ou foliar) promovem aumento do seu teor nas raízes de cenoura, porém o selenato via foliar é a fonte e forma mais efetiva. Dessa forma, é possível aumentar os teores de Se na parte comestível da cenoura e, assim, favorecer a in...

Phenolic compounds are natural antioxidants and can be found with abundance in fruits and vegetables. One of the first methods created for analyzing phenolic compounds was the Folin-Denis method; and hereafter, the Folin Ciocalteu method was developed and recently, one of the most recent method is the Fast Blue. Due to the importance of these compounds in food, this work aimed to determine the total phenolic compounds in three fruits, such as: Passion Fruit, “Palmer” mango and “Pera” orange. In addition, these fruits were analyzed through three different determination methods. Furthermore, the content of vitamin C, soluble solids, titratable acidity and pH of these fruits were evaluated. Based on the results, it was verified that there was no difference among the values of vitamin C, soluble solids and TA in relation to those found in the literature. When comparing the three methods (Fast Blue BB, Folin-Ciocalteu Reagent and Folin-Denis Reagent), the results showed a difference in the phenolic compounds that may be related to the distinct reagents used in each method and its different action.

Neste trabalho empregou-se a técnica de casting para a produção de filmes. Utilizou-se quantidades distintas de amido de milho, glicerina e extrato de própolis-verde, sendo avaliadas as propriedades mecânicas (módulo de Young, elasticidade e tensão à ruptura) dos materiais obtidos. Verificou-se o efeito das variáveis e de suas interações pelo gráfico de Pareto. Superfícies de resposta foram construídas em testes conduzidos com 95% de confiança. A análise dos resultados indicou que o amido de milho foi o que mais influenciou na determinação do módulo de Young. Por outro lado, para a elongação, a glicerina, utilizada como agente plastificante, foi o fator mais relevante. Na análise da tensão à ruptura, observou-se que a interação entre a glicerina e o extrato de própolis-verde foi a mais significativa. Foi então selecionado o filme que apresentou as características mais adequadas no acondicionamento de mudas de alface. Os resultados indicaram que a amostra produzida a partir de 4 g de amido de milho, 1 g de glicerina e 0,12 g de extrato de própolis-verde foi a mais apropriada. Com relação ao acondicionamento da muda de alface, foi feita uma análise visual e macroscópica com a finalidade de verificar a resistência do filme biodegradável quando o substrato e a muda foram adicionados na embalagem. Foi observado que o material sintetizado e escolhido teve uma capacidade adequada para a sua retenção, o que favorece e ratifica o seu emprego, uma vez que, ao ser biodegradável, pode se tornar substituto de plásticos convencionais. Palavras-chave: Técnica casting. Módulo de Young. Elasticidade. Tensão à ruptura.   Evaluation of the mechanical properties of biodegradable films and their application in packaging for packaging plants Abstract In this work the technique of casting was used for the production of films. Different quantities of corn starch, glycerin and propolis-green extract were used, and the mechanical properties (Young's modulus, elasticity and tensile strength) of the materials obtained were evaluated. The effect of the variables and their interactions on the Pareto graph was verified. Response surfaces were constructed in tests conducted with 95% confidence. The analysis of the results indicated that the corn starch was the most influential in determining the Young's modulus. On the other hand, for elongation, glycerin, used as a plasticizing agent, was the most relevant factor. In analyzing the rupture stress, it was observed that the interaction between glycerin and the propolis-green extract was the most significant. It wasthenselectedthefilmthatpresentedthemost suitable characteristics in the packaging of lettuce seedlings. The results indicated that the sample produced from 4 g of cornstarch, 1 g of glycerin and 0.12 g of propolis-green extract was the most appropriate. Regarding the conditioning of the lettuce change, a visual and macroscopic analysis was performed to verify the resistance of the biodegradable film when the substrate and the change were added to the packaging. It hás been observed that the synthesized and selected material hás the proper capacity for its retention, which favors and ratifies its use, since, being biodegradable, it can be come a substitute for conventional plastics. Keywords:Casting technique. Young's module. Elasticity. Tensionto break.