José Teixeira Filho

Phenolic compounds from yerba mate based beverages--A multivariate optimisation.

This work used a central composite design to optimise a reverse phase high performance liquid chromatographic method for the simultaneous separation of gallic, syringic, 5-caffeoylquinic, caffeic, p-coumaric, ferulic, 3,4-dicaffeoylquinic, 3,5-dicaffeoylquinic, 4,5-dicaffeoylquinc acids, rutin in aqueous extracts of yerba mate (Ilex paraguariensis). The effect of the linear gradient time, the initial and the final methanol concentration in the mobile phase on the peak resolution and peak symmetry was evaluated. The 26 responses obtained were simultaneously optimised using the desirability method of Derringer and Suich. According to results, the increasing in the resolution and peak symmetry was achieved by using lesser levels of methanol in both initial and final gradient elution (-1.68, -1), as well as higher gradient times (+1, +1.68). The optimal condition (13.9-40% of methanol in 39.4 min) were successfully applied for analysis of chimarrão, tererê and mate tea aqueous extracts, which showed as excellent sources of chlorogenic acids.

Avaliação preliminar das cargas difusas de origem rural, em uma sub-bacia do Rio Jaguari, SP

Official water quality and flow data from Jaguari River were used to assess the diffused loads of nutrients from rural areas into surface waters. Mathematical models of mean daily loads of total nitrogen (TN) and total phosphorus (TP) were generated through the application of simple statistical procedures to field data collected from 1999 to 2002. The models obtained were validated with field data collected from 1996 to 1998. The application of the model showed that, on average, 68.2% of the TN annual loads and 77.3% of the TP annual loads were transported through the sub-basin during the raining season. Assuming the mean baseflow loads as 1706.5 kg TN d-1 and 165.7 kg TP d-1, the annual diffused loads obtained - primarily from rural sources - were equivalent to 55.1 and 69.4% of the total annual loads of TN and TP transported through the sub - basin, respectively. The mean export coefficients from diffused loads for TN and TP were equal to 230 and 40 kg km-2 year-1, respectively. In may be concluded that controlling the diffused loads of TP from rural areas should decrease the high concentrations observed.

Validação de metodologia para a determinação simultânea dos antioxidantes sintéticos em óleos vegetais, margarinas e gorduras hidrogenadas por CLAE/UV

The use of antioxidants either to prevent or retard foods lipids oxidation was approved after inquires that verified their security within a daily intake limit. In this study, the methodology was developed and validated for the analysis of synthetic antioxidants: propylgallate (PG), tert-butylhydroquinone (TBHQ), butylhydroxyanisole (BHA), octylgallate (OG) and butylhydroxytoluene (BHT) in vegetables oils, margarine and hydrogenated fats by high performance liquid chromatographic. The methodology revealed itself efficient, with recovery rates above 90% for all antioxidant substances, besides good linearity in concentration range of 40-240 mg kg-1 (r = 0,999), repeatability with CV < 3,7% and limit of quantification 16.55, 10.32, 1.40, 3.76 and 9.30 mg/kg for BHT, BHA, PG, OG and TBHQ, respectively.

Efeito da faixa-filtro na retenção de atrazina em escoamento superficial

O presente estudo avaliou a eficacia de faixas-filtro de comprimentos de 0, 5 e 10 m na reducao de atrazina em agua de escoamento provinda de areas cultivadas com milho, gerada por 4 chuvas simuladas. Na faixa-filtro utilizou-se braquiaria (Brachiaria decumbens) como elemento de retencao da atrazina. A diminuicao dos valores mobilizados e transportados de atrazina encontrados, demonstrou a eficiencia dessa faixa. A faixa de 5 m reduziu, em relacao a parcela sem faixa (0 m de comprimento), nos 4 eventos de chuva simulada, um total de 73,8% da atrazina aplicada ao solo. Na de 10 m os valores foram maiores, tendo havido reducao de 89,7%, a qual foi obtida a partir do aumento efetivo da infiltracao da agua do escoamento superficial na faixa-filtro. Quanto aos valores de concentracao, nao se observaram reducoes efetivas, ficando evidente que a faixa vegetada pode ser eficiente na reducao de substância em diluicao na agua, como no caso da atrazina sem provocar, no entanto, diminuicao das concentracoes presentes.

Chlorogenic acid isomer contents in 100 plants commercialized in Brazil

This study analysed 100 plants employed in Brazil as ingredients to infusions for their caffeic acid, 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 3,4-dicaffeoylquinic acid (3,4-DQA), 3,5-dicaffeoylquinic acid (3,5-DQA), and 4,5-dicaffeoylquinic acid (4,5-DQA) contents. The samples were collected from public markets and analysed using ultra-high performance liquid chromatography (UPLC). The highest concentrations of chlorogenic acids were found in yerba mate (Ilex paraguariensis), 9,2g·100g-1, white tea (Camellia sinensis), winters bark (Drimys winteri), green tea (Camellia sinensis), elderflower (Sambucus nigra), and Boehmeria caudata (known as assa-peixe in Brazil), 1,1g·100g-1. The present work showcased the investigation of chlorogenic acids in a wide range of plants not yet studied in this regard and also resulted in a comparative table which explores the content of six isomers in the samples.

Scaling Up of Leaf Transpiration and Stomatal Conductance of Eucalyptus grandis x Eucalyptus urophylla in Response to Environmental Variables

© 2013 Tonello and Filho, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Scaling Up of Leaf Transpiration and Stomatal Conductance of Eucalyptus grandis x Eucalyptus urophylla in Response to Environmental Variables