Characterization of polyphenol oxidase from purple sweet potato (Ipomoea batatas L. Lam) and its affinity towards acylated anthocyanins and caffeoylquinic acid derivatives.

Biochemical characterization of polyphenol oxidase (PPO) present in purple sweet potato (PSP) is a key step in developing efficient methodologies to control oxidative damage caused by this enzyme to the valuable components of PSP, such as caffeoylquinic acid derivatives and acylated anthocyanins. Thus, this work focused on the assessment of the effects of pH, temperature, and chemical agents on the PPO activity as well as characterization of the PPO substrate specificity towards major phenolic compounds found in PSP. The optimum conditions of enzyme activity were pH 7 and a temperature range of 20-30 °C at which phenolic substrates were oxidized with 72.5-99.8% yield. Zn2+ ions remarkably reduced PPO activity while Cu2+ ions improved enzyme performance. The highest substrate preference was shown for 3,4,5-tri-caffeoylquinic and 3,5-di-caffeoylquinic acid, followed by 5-caffeoylquinic and caffeic acid, 3,4- and 4,5-di-caffeoylquinic acids, peonidin-3-caffeoyl-p-hydroxybenzoyl-sophoroside-5-glucoside. The highest Km values were found for 4,5-feruloyl-caffeoylquinic acid and catechol.

Strategies to include sweet potato meal associated with the use of exogenous enzymes, in broiler chicken feed / Estratégias de inclusão da farinha de batata doce associada ao uso de enzimas exógenas em rações de frangos de corte

This work evaluated the effect of including sweet potato meal (SPM), as an alternative to corn in broiler chicken diets, on performance, carcass yield, intestinal morphometry, organ biometry, meat quality and drumstick pigmentation. The study used 936 male Cobb-500 chicks. The experiment had a completely randomized, 3x2 factorial design, with three diet types. These included corn as the energetic ingredient in the standard diet (corn-soybean meal, CSM), and an increasing (ISP) and decreasing (DSP) inclusion of sweet potato meal as a corn substitute, in association with exogenous enzymes, for a total of six treatments with six repetitions and 26 birds per plot. During the period of 1 to 21 days, there was an interaction (P0.05) by the factors evaluated. Sweet potato meal, independent of the inclusion program (ISP/DSP) and enzyme supplementation, could partially substitute corn in broiler chicken feed, guaranteeing good performance, carcass yield and meat quality.

Avaliou-se o efeito da inclusão de farinha de batata doce (FBD), como alternativa ao milho em dietas de frangos de corte sobre o desempenho, rendimento da carcaça, morfometria intestinal, biometria de órgãos, qualidade de carne e pigmentação de canela. Foram utilizados 936 pintos de um dia, machos, da linhagem Cobb-500. Adotou-se um DIC em esquema fatorial 3x2, sendo três tipos de dietas, sendo o milho o ingrediente energético na dieta padrão (MFS), inclusão crescente (BDC) e decrescente (BDD) de farinha de batata doce como substituto parcial ao milho, associadas ou não ao uso de enzimas exógenas, totalizando seis tratamentos com seis repetições e 26 aves por parcela. No período de 1 a 21 dias, houve interação (P0,05) pelos fatores avaliados. A farinha de batata doce independente do programa de inclusão (BDC/BDD) e da suplementação de enzimas pode ser usada em rações de frangos de corte, garantindo bom desempenho, rendimento de carcaça e qualidade de carne.

Strategies to include sweet potato meal associated with the use of exogenous enzymes, in broiler chicken feed / Estratégias de inclusão da farinha de batata doce associada ao uso de enzimas exógenas em rações de frangos de corte

This work evaluated the effect of including sweet potato meal (SPM), as an alternative to corn in broiler chicken diets, on performance, carcass yield, intestinal morphometry, organ biometry, meat quality and drumstick pigmentation. The study used 936 male Cobb-500 chicks. The experiment had a completely randomized, 3x2 factorial design, with three diet types. These included corn as the energetic ingredient in the standard diet (corn-soybean meal, CSM), and an increasing (ISP) and decreasing (DSP) inclusion of sweet potato meal as a corn substitute, in association with exogenous enzymes, for a total of six treatments with six repetitions and 26 birds per plot. During the period of 1 to 21 days, there was an interaction (P<0.05) for the weight gain (WG) variable; the CSM diets promoted greater WG in relation to the ISP and DSP groups, when supplemented with exogenous enzymes. There was an increase (P<0.05) in surface absorption of the jejunum villi and relative weight of the pancreas, and worse feed conversion (FC), for the ISP and DSP diets. With exception of the pancreas, for the entire period of 1 to 39 days the performance, yield of the carcass and cuts, meat quality, relative weight of the liver, and feet pigmentation variables were not affected (P>0.05) by the factors evaluated. Sweet potato meal, independent of the inclusion program (ISP/DSP) and enzyme supplementation, could partially substitute corn in broiler chicken feed, guaranteeing good performance, carcass yield and meat quality.(AU)

Avaliou-se o efeito da inclusão de farinha de batata doce (FBD), como alternativa ao milho em dietas de frangos de corte sobre o desempenho, rendimento da carcaça, morfometria intestinal, biometria de órgãos, qualidade de carne e pigmentação de canela. Foram utilizados 936 pintos de um dia, machos, da linhagem Cobb-500. Adotou-se um DIC em esquema fatorial 3x2, sendo três tipos de dietas, sendo o milho o ingrediente energético na dieta padrão (MFS), inclusão crescente (BDC) e decrescente (BDD) de farinha de batata doce como substituto parcial ao milho, associadas ou não ao uso de enzimas exógenas, totalizando seis tratamentos com seis repetições e 26 aves por parcela. No período de 1 a 21 dias, houve interação (P<0,05) para as variáveis de ganho de peso (GP) onde as dietas de MFS promoveram maior GP em relação aos grupos BDC e BDD quando suplementado com enzimas exógenas. Houve aumento (P<0,05) da superfície de absorção das vilosidades do jejuno, do peso relativo do pâncreas e piora na conversão alimentar (CA) promovido pelas dietas com BDC e BDD. No período integral de 1 a 39 dias (com exceção para o pâncreas) as variáveis desempenho, rendimento da carcaça e dos cortes, qualidade de carne, peso relativo do fígado e pigmentação das canelas não foram afetados (P>0,05) pelos fatores avaliados. A farinha de batata doce independente do programa de inclusão (BDC/BDD) e da suplementação de enzimas pode ser usada em rações de frangos de corte, garantindo bom desempenho, rendimento de carcaça e qualidade de carne.(AU)

Indirect determination of sulfite using a polyphenol oxidase biosensor based on a glassy carbon electrode modified with multi-walled carbon nanotubes and gold nanoparticles within a poly(allylamine hydrochloride) film.

The modification of a glassy carbon electrode with multi-walled carbon nanotubes and gold nanoparticles within a poly(allylamine hydrochloride) film for the development of a biosensor is proposed. This approach provides an efficient method used to immobilize polyphenol oxidase (PPO) obtained from the crude extract of sweet potato (Ipomoea batatas (L.) Lam.). The principle of the analytical method is based on the inhibitory effect of sulfite on the activity of PPO, in the reduction reaction of o-quinone to catechol and/or the reaction of o-quinone with sulfite. Under the optimum experimental conditions using the differential pulse voltammetry technique, the analytical curve obtained was linear in the concentration of sulfite in the range from 0.5 to 22 µmol L(-1) with a detection limit of 0.4 µmol L(-1). The biosensor was applied for the determination of sulfite in white and red wine samples with results in close agreement with those results obtained using a reference iodometric method (at a 95% confidence level).

Evaluación de la dinámica del crecimiento in vitro en callos de Ipomoea batatas / Evaluation of the dynamics of the growth in vitro callus of Ipomoea batatas

El cultivo del boniato presenta una gran importancia, ya que se puede emplear en la alimentación humana y animal, así como en la industria; el mismo produce raíces reservantes de gran valor calórico y nutritivo con alto contenido de carbohidratos. Entre las raíces y tubérculos cultivados es el segundo en importancia y representa más del 80% de la producción mundial. El empleo de las técnicas in vitro constituye una poderosa herramienta en la explotación comercial, propiciando el empleo de la micropropagación en diferentes especies. Para desarrollar el presente trabajo se recolectaron raíces tuberosas pertenecientes al clon Inivit B 93-1. Se procedió a la formación de callos potencialmente embriogénicos, para lo cual se emplearon explantes de limbos foliares, desinfectados con hipoclorito de sodio (1%) y sembrados en el medio de cultivo propuesto por Murashige y Skoog (1962), vitaminas MS (10,0 ml/l-1), mioinositol (100 mg/l-1), sacarosa (3%), gelrite (0,2%), 2,4-D (0,25-2,5 mg/l-1) y 6-BAP (0,25-1,0 mg/l-1), el pH fue ajustado a 5,8 ± 0,01 mantenidos en la oscuridad durante treinta días, lográndose los mejores resultados con el uso del 2,4-D (0,50 mg/l-1) y 6-BAP (0,25 mg/l-1), y en los mismos se evaluó la dinámica del crecimiento y se lograron los mejores resultados entre los 28 y 32 días después de la siembra, para lo cual los resultados obtenidos servirán de base a otros estudios y permitirán evaluar, controlar y desarrollar estrategias para la conservación y el uso de los recursos naturales, dando cumplimiento al objetivo referente a estudiar la dinámica del crecimiento en la formación de callos potencialmente embriogénicos en el cultivo del boniato.

The cultivation of the sweet potato presents a great importance, since you can use in the human feeding, animal as well as in the industry, the same one produces roots reservantes of great caloric and nutritious value with high content of carbohydrates. Between the roots and cultivated tubers it is the second in importance and it represents more than 80% of the world production. The employment of the techniques in vitro constitutes a powerful tool in the commercial, propitiated exploitation the employment of the micropropagación in different species. It is for it that you/they were gathered to develop the present work tuberous roots of the clon INIVIT B 93-1. Was realized the formation of callus with embryogenic structures, explantes of leaves were used, disinfected with hipoclorito of sodium (1%) and inoculated in the tissue culture medium proposed by Murashige and Skoog (1962), vitamins MS (10.0 ml/l-1), myoinositol (100 mg/l-1), sucrose (3%), gelryte (0.2%), 2,4-D (0.25-2.5 mg/l-1) and 6-BAP (0.25-1.0 mg/l-1), the pH was adjusted 5.8 ± 0.01 maintained in the darkness during thirty days, being achieved the best results with the use of the 2,4-D (0.50 mg/l-1) and 6-BAP (0,25 mg/l-1) and was evaluated the grow dynamic and obtained the better resulted between 28 and 32 days after culture, for that which the obtained results will serve from base to other studies and they will allow to evaluate, to control and to develop strategies for the conservation and use of the natural resources, giving execution to the objective with respect to studying the dynamics of the growth potentially in the formation of tripes embriogénicos in the cultivation of the sweet potato.

Kinetic approach for the enzymatic determination of levodopa and carbidopa assisted by multivariate curve resolution-alternating least squares.

A combination of kinetic spectroscopic monitoring and multivariate curve resolution-alternating least squares (MCR-ALS) was proposed for the enzymatic determination of levodopa (LVD) and carbidopa (CBD) in pharmaceuticals. The enzymatic reaction process was carried out in a reverse stopped-flow injection system and monitored by UV-vis spectroscopy. The spectra (292-600 nm) were recorded throughout the reaction and were analyzed by multivariate curve resolution-alternating least squares. A small calibration matrix containing nine mixtures was used in the model construction. Additionally, to evaluate the prediction ability of the model, a set with six validation mixtures was used. The lack of fit obtained was 4.3%, the explained variance 99.8% and the overall prediction error 5.5%. Tablets of commercial samples were analyzed and the results were validated by pharmacopeia method (high performance liquid chromatography). No significant differences were found (alpha=0.05) between the reference values and the ones obtained with the proposed method. It is important to note that a unique chemometric model made it possible to determine both analytes simultaneously.

Flow-batch technique for the simultaneous enzymatic determination of levodopa and carbidopa in pharmaceuticals using PLS and successive projections algorithm.

An enzymatic flow-batch system with spectrophotometric detection was developed for simultaneous determination of levodopa [(S)-2 amino-3-(3,4-dihydroxyphenyl)propionic acid] and carbidopa [(S)-3-(3,4-dihydroxyphenyl)-2-hydrazino-2-methylpropionic acid] in pharmaceutical preparations. The data were analysed by univariate method, partial least squares (PLS) and a novel variable selection for multiple lineal regression (MLR), the successive projections algorithm (SPA). The enzyme polyphenol oxidase (PPO; EC 1.14.18.1) obtained from Ipomoea batatas (L.) Lam. was used to oxidize both analytes to their respective dopaquinones, which presented a strong absorption between 295 and 540 nm. The statistical parameters (RMSE and correlation coefficient) calculated after the PLS in the spectral region between 295 and 540 nm and MLR-SPA application were appropriate for levodopa and carbidopa. A comparative study of univariate, PLS, in different ranges, and MLR-SPA chemometrics models, was carried out by applying the elliptical joint confidence region (EJCR) test. The results were satisfactory for PLS in the spectral region between 295 and 540 nm and for MLR-SPA. Tablets of commercial samples were analysed and the results obtained are in close agreement with both, spectrophotometric and HPLC pharmacopeia methods. The sample throughput was 18 h(-1).

Synthesis, structure, properties, and phosphatase-like activity of the first heterodinuclear Fe(III)Mn(II) complex with the unsymmetric ligand H(2)BPBPMP as a model for the PAP in sweet potato.

The new heterodinuclear mixed valence complex [Fe(III)Mn(II)(BPBPMP)(OAc)(2)]ClO(4) (1) with the unsymmetrical N(5)O(2) donor ligand 2-bis[((2-pyridylmethyl)-aminomethyl)-6-((2-hydroxybenzyl)(2-pyridylmethyl))-aminomethyl]-4-methylphenol (H(2)BPBPMP) has been synthesized and characterized. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, and has an Fe(III)Mn(II)(mu-phenoxo)-bis(mu-carboxylato) core. Two quasireversible electron transfers at -870 and +440 mV versus Fc/Fc(+) corresponding to the Fe(II)Mn(II)/Fe(III)Mn(II) and Fe(III)Mn(II)/Fe(III)Mn(III) couples, respectively, appear in the cyclic voltammogram. The dinuclear Fe(III)Mn(II) center has weakly antiferromagnetic coupling with J = -6.8 cm(-1) and g = 1.93. The (57)Fe Mössbauer spectrum exhibits a single doublet, delta = 0.48 mm s(-1) and DeltaE(Q) = 1.04 mm s(-1) for the high spin Fe(III) ion. Phosphatase-like activity at pH 6.7 with the substrate 2,4-bis(dinitrophenyl)phosphate reveals saturation kinetics with the following Michaelis-Menten constants: K(m) = 2.103 mM, V(max) = 1.803 x 10(-5) mM s(-1), and k(cat) = 4.51 x 10(-4) s(-1).