Rapid Method For The Determination Of Organic Acids In Wine By Capillary Electrophoresis With Indirect Uv Detection

A capillary electrophoresis method for organic acids in wine was developed and validated. The optimal electrolyte consisted of 10 mmol/L 3,5-dinitrobenzoic acid (DNB) at pH 3.6 containing 0.2 mmol/L cetyltrimethylammonium bromide as flow reverser. DNB was chosen because it has an effective mobility similar to the organic acids under investigation, good buffering capacity at pH 3.6, and good chromophoric characteristics for indirect UV-absorbance detection at 254 nm. Sample preparation involved dilution and filtration. The method showed good performance characteristics: Linearity at 6 to 285 mg/L (r > 0.99); detection and quantification limits of 0.64 to 1.55 and 2.12 to 5.15 mg/L, respectively; separation time of less than 5.5 min. Coefficients of variation for ten injections were less than 5% and recoveries varied from 95% to 102%. Application to 23 samples of Brazilian wine confirmed good repeatability and demonstrated wide variation in the organic acid concentrations. © 2008 Elsevier Ltd. All rights reserved.206548552Arellano, M., Andrianary, J., Dedieu, F., Couderc, F., Puig, P., Method development and validation for the simultaneous determination of organic acid and inorganic acids by capillary zone electrophoresis (1997) Journal of Chromatography A, 765, pp. 321-328Arellano, M., Couderc, F., Puig, P.H., Simultaneous separation of organic and inorganic acids by capillary zone electrophoresis. Application to wines and fruit juices (1997) American Journal of Enology and Viticulture, 48, pp. 408-412Bianchi, F., Careri, M., Corradini, C., Novel approach for the rapid determination of water-soluble organic acids in wine by co-electroosmotic flow capillary zone electrophoresis (2005) Journal of Separation Science, 28, pp. 898-904Castiñeira, A., Peña, R.M., Herrero, C., García-Martín, S., Simultaneous determination of organic acids in wine samples by capillary electrophoresis and UV detection: Optimization with five different background electrolytes (2000) HRC - Journal of High Resolution Chromatography, 23, pp. 647-652Castiñeira, A., Peña, R.M., Herrero, C., García-Martín, S., Analysis of organic acids in wine by capillary electrophoresis with direct UV detection (2002) Journal of Food Composition and Analysis, 15, pp. 319-331De Villiers, A., Lynen, F., Crouch, A., Sandra, P., A robust capillary electrophoresis method for the determination of organic acids in wines (2003) European Food Research and Technology, 217, pp. 535-540Esteves, V.I., Lima, S.S.F., Lima, D.L.D., Duarte, A.C., Using capillary electrophoresis for the determination of organic acids in Port wine (2004) Analytica Chimica Acta, 5131, pp. 163-167García Moreno, M.V., Jurado Campoy, C.J., García Barroso, C., Method devised for determining low molecular weight organic acids in vinic samples by capillary electrophoresis: Validation of the method with real samples (2001) European Food Research and Technology, 213, pp. 381-385Hirokawa, T., Nishino, M., Aoki, N., Kiso, Y., Table of isotacophoretic indices I. Simulating qualitative indices of 287 anionic substances in the range pH 3-10 (1983) Journal of Chromatography, 271, pp. D1-D106Kandl, T., Kupina, S., An improved capillary electrophoresis procedure for the determination of organic acids in grape juice and wine (1999) American Journal of Enology and Viticulture, 50, pp. 155-161Kelly, L., Nelson, R.J., Capillary zone electrophoresis of organic acids and anions (1993) Journal of Liquid Chromatography and Related Technologies, 16, pp. 2103-2112Kenney, B.F., Determination of organic acids in food samples by capillary electrophoresis (1991) Journal of Chromatography A, 546, pp. 423-430Klampfl, C.W., Katzmayr, M.U., Buchberger, W., Separation of inorganic and organic anions by capillary zone electrophoresis with simultaneous indirect UV and conductivity detection (1998) Electrophoresis, 19, pp. 2459-2464(2007) Handbook of capillary and microchip electrophoresis and associated microtechniques. 3rd ed., , Landers J.P. (Ed), CRC Press Inc, Boca RatonLevi, V., Wehr, T., Talmadge, K., Zhu, M., Analysis of organic acids in wines by capillary electrophoresis and HPLC (1993) American Laboratory, 25, pp. 29-32Mato, I., Suárez-Luque, S., Huidobro, J.F., Simple determination of main organic acid in grape juice and wine by using capillary zone electrophoresis with direct UV detection (2007) Food Chemistry, 102, pp. 104-112Moreno, M.V.G., Jurado, C.J., Barroso, C.G., Determination of organic acids by capillary electrophoresis with simultaneous addition of Ca and Mg as complexing agents (2003) Chromatographia, 57, pp. 185-189Ribereau-Gayon, P., Gloris, Y., Maujean, A., Dubourdieu, D., (2000) Handbook of enology, The chemistry of wine, stabilization and treatments, 2. , Wiley, New YorkSaavedra, L., Barbas, C., Validated capillary electrophoresis method for small-anions measurement in wines (2003) Electrophoresis, 24, pp. 2235-2243Sing Fung, Y., Man Lau, K., Analysis of organic acids and inorganic anions in beverage drinks by capillary electrophoresis (2003) Electrophoresis, 24, pp. 3224-3232Stathakis, C., Cassidy, R.M., Effect of electrolyte composition in the capillary electrophoretic separation of inorganic/organic anions in the presence of cationic polymers (1995) Journal of Chromatography A, 699, pp. 353-361Zoecklein, B.W., Fugelsang, K.C., Gump, B.H., Nury, F.S., (1999) Wine analysis and production, , Aspen Publishers Inc, Gaithersbur

Efeito do envelhecimento acelerado na avaliação da qualidade fisiológica de sementes de trigo Effect of the accelerated aging in the evaluation of the physiological quality in wheat seeds

A pesquisa foi conduzida no Laboratório de Tecnologia e Análise de Sementes, no Centro de Ciências Agrárias, da Universidade Federal do Espírito Santo, Alegre-ES, com o objetivo de estudar a temperatura e o período de exposição adequados para a avaliação de sementes de trigo da cultivar Aliança pelo teste de envelhecimento acelerado. As sementes foram expostas às temperaturas de 41º, 43º e 45ºC e umidade relativa do ar de 100%, por períodos de zero, 24, 48, 72 e 96 horas. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições de 25 sementes. A qualidade fisiológica das sementes foi avaliada pelos testes de: germinação e vigor (comprimento da raiz primária e massa seca). Temperaturas de 41ºC e tempos de exposição de 24 e 48 horas são os mais indicados para o teste de envelhecimento acelerado em trigo; sob temperatura de 43ºC, recomenda-se utilizar 24 horas de exposição das sementes; a temperatura de 45ºC é letal.<br>This research was carried out in the Laboratory of Seeds Technology and Analysis of the Fitotecnia Department of the Agrarian Science Center of Federal University of Espirito Santo, Alegre, Espirito Santo State, Brazil, with the objective to evaluate the temperature and the period of exposition adjusted for the evaluation of the seeds wheat cultivar Alliance for the accelerated aging test. The seeds were exposed under temperatures of 41º, 43º and 45ºC and relative humidity of the air of 100%, for periods of zero, 24, 48, 72 and 96 hours, using the completely randomized design, with four replications of 25 seeds. The physiological quality of the seeds was evaluated by germination and vigor tests (radicule length and dry matter). Temperature of 41ºC for periods of 24 and 48 hours of treatment were the more indicated for the wheat aging; under temperature of the 43ºC was recommended 24 hours of exposition. Treatment of the seeds with accelerated aging using temperature of 45ºC determined the death of the seeds, culminating with deterioration

Primed carrot seeds performance under water and temperature stress Desempenho de sementes osmocondicionadas de cenoura sob estresse hídrico e térmico

Uniformity and percentage of seedling emergence of direct-seeded vegetables have a major impact on their yield and quality. Depending on temperature and soil water potential, carrot seeds performance in the field is poor justifying the use of techniques to accelerate the germination and seedling emergence. The objective of this work was to evaluate the effects of priming treatments, with and without aeration, on carrot seeds performance under water and temperature stress. Two seed lots of carrots, Brasília cultivar, were primed in PEG 6000 -1.0 and -1.2 MPa solutions, for four and eight days, at 20ºC, using two imbibition methods: priming in paper towel moistened with the respective solutions and immersion into aerated osmotic solutions. Non-primed seeds were used as control. After priming, the seeds were dried at room temperature until reach initial seed moisture content. The seeds were submitted to the following tests: germination, first count, seedling emergence in the field, germination at sub-optimal (15ºC) and supra-optimal temperature (30ºC) and germination under water stress (PEG 6000 at -0.4 MPa). Priming in -1.0 and -1.2 MPa PEG 6000 during four and eight days can be useful for improving carrot seedling emergence in the field and seed performance under supra and sub-optimal temperatures. Aeration of the peg solution was beneficial when seeds were primed at -1.2 MPa for eight days.<br>Na cultura da cenoura são constantes os problemas relativos ao desempenho das sementes em campo, justificando técnicas que acelerem a germinação das sementes e a emergência das plântulas. O objetivo deste trabalho foi avaliar o efeito do condicionamento osmótico, com e sem uso de soluções aeradas, no desempenho de sementes de cenoura sob estresse hídrico e térmico. Para tanto, sementes de dois lotes, cv. Brasília, foram condicionadas em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, a 20ºC, utilizando-se dois métodos de embebição para o condicionamento: em papel toalha umedecido com as respectivas soluções e imersão em soluções osmóticas aeradas. Sementes não condicionadas foram utilizadas como testemunha. Após o condicionamento, as sementes foram secas em ambiente de laboratório até atingirem o grau de umidade inicial. Em seguida, foram avaliadas pelos seguintes testes: germinação, primeira contagem de germinação, emergência das plântulas em campo, germinação a temperatura sub (15ºC) e supra-ótima (30ºC) e germinação sob estresse hídrico (PEG 6000 a -0,4 MPa). O condicionamento osmótico das sementes de cenoura em soluções de PEG 6000 a -1,0 e -1,2 MPa, por quatro e oito dias, é recomendado para aumentar a emergência de plântulas em campo e o desempenho sob temperatura sub e supra-ótima. O uso de soluções aeradas de PEG foi benéfico apenas quando as sementes foram condicionadas a -1,2 MPa por oito dias

Biorregulador e pré-condicionamento osmótico na germinação de sementes e no crescimento inicial da muda de carobinha (Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença) - Bignoniaceae Bioregulator and priming on seed germination and initial growth of "carobinha" (Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença - Bignoniaceae) seedlings

O objetivo deste trabalho foi avaliar o efeito de tratamentos pré-germinativos na emergência das plantas e no crescimento inicial das mudas de Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença. Foram realizados dois experimentos. No primeiro, as sementes, separadas em claras e escuras, foram submetidas aos tratamentos pré-germinativos: 1) KNO3 (20000 mg L-1); 2) ácido giberélico (GA3) 50 mg L-1, 3) GA3 100 mg L-1 4) GA3 200 mg L-1; 5) Stimulate 5 mL 0,5 kg-1 de sementes; 6) Stimulate 10 mL 0,5 kg-1 de sementes; 7) água 24 horas; 8) testemunha. A semeadura foi realizada em bandejas de células preenchidas com substrato terra + substrato comercial. Os cinco melhores tratamentos foram selecionados para avaliação do crescimento da muda. As plantas com 120 dias de idade provenientes dos seguintes tratamentos: 3) GA 100 mg L-1 4) GA 200 mg L-1; 5) Stimulate 5 mL 0,5 Kg-1 de sementes 6) Stimulate 10 mL 0,5 Kg-1 de sementes e 8) Testemunha, foram transplantadas para embalagens de plástico de 3 Kg com substrato terra + areia + cama-de-frango (1:1:1 - v:v), mantidas em sombreamento de 50% e avaliadas aos 70, 130, 170 e 210 dias após o transplante. Em geral, as sementes claras apresentaram maior germinabilidade e índice de velocidade de germinação (IVG) em relação às sementes escuras. Entretanto, as plantas provenientes dessas sementes apresentaram menor crescimento do que as plantas provenientes das sementes escuras. No segundo experimento as sementes foram pré-embebidas em solução de: 1) PEG 6000 (-1,0 MPa); 2) PEG 6000 (-1,0 MPa) + KNO3 (20000 mg L-1) (-1,0 MPa); 3) KNO3 (20000 mg L-1) (-1,0 MPa); 4) Água e 5) água deionizada, e incubadas em BOD a 10ºC e 20ºC durante 0 (controle), 6, 12 e 24 horas. Após esses períodos elas foram secas em ambiente de laboratório até atingirem a massa apresentada antes do condicionamento e, posteriormente, incubadas em BOD a 20-30ºC com 8 h escuro e 12 h de luz. Os tratamentos pré-germinativos não interferiram na vitalidade e no vigor das sementes osmocondicionadas por até 12 horas. Não houve diferença entre as temperaturas de 10 e 20ºC para germinabilidade (60 %) e IVG, porém a temperatura de 10ºC originou plântulas com maior massa fresca (95,7 mg) e comprimento médio de raiz (3,2 cm) e de parte aérea (2,6 cm). O osmocondicionamento por 24 horas causou redução na qualidade das sementes e vigor das plântulas.<br>The aim of this work was to evaluate the effect of pregerminative treatments on the emergence and initial growth of Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença seedlings. Two experiments were carried out. In the first experiment, seeds were separated into light and dark seeds and were subjected to the following pregerminative treatments: 1) KNO3 (20000 mg L-1); 2) Gibberellic acid (GA3) 50 mg L-1, 3) GA3 100 mg L-1 4) GA3 200 mg L-1; 5) Stimulate 5 mL 0.5 kg-1 seeds; 6) Stimulate 10 mL 0.5 kg-1 seeds; 7) Water 24h; and 8) Control. The sowing was performed on polystyrene trays filled with land + commercial substrate. The five best treatments were selected to evaluate seedling growth. Plants aged 120 days from treatments 3, 4, 5, 6 and 8 were transplanted to plastic bags (3kg) filled with land + sand + poultry manure (1:1:1 - v:v), kept under 50% shading and evaluated at 70, 130, 170 and 210 days after transplanting. In general, light seeds had higher germinability and germination speed index (GSI) than the dark ones. However, the plants obtained from these seeds had lower growth than plants from dark seeds. In the second experiment, seeds were primed in the solutions: 1) PEG 6000 (-1.0 MPa); 2) PEG 6000 (-1.0 MPa) + KNO3 (20000 mg L-1) (-1.0 MPa); 3) KNO3 (20000 mg L-1) (-1.0 MPa); 4) Water; and 5) Deionized water, and incubated in a BOD chamber at 10 and 20ºC for 0 (control), 6, 12 and 24h. Then, seeds were dried at room temperature until reaching the matter presented before priming and incubated in a BOD chamber at 20-30ºC with 8h dark - 12h light. The pregerminative treatments did not interfere with the vitality and vigor of seeds primed for up to 12h. There was no difference between 10 and 20ºC for germinability (60%) and GSI. However, the temperature of 10ºC led seedlings to present higher fresh matter (95.7 mg) and mean root (3.2 cm) and shoot (2.6 cm) length. Priming for 24h decreased seed quality and seedling vigor