In this work, an innovative polyphenol oxidase biosensor was developed from Jenipapo (Genipa americana L.) fruit and used to assess phenolic compounds in industrial effluent samples obtained from a textile industry located in Jaraguá-GO, Brasil. The biosensor was prepared and optimized according to: the proportion of crude vegetal extract, pH and overall voltammetric parameters for differential pulse voltammetry. The calibration curve presented a linear interval from 10 to 310 µM (r2 = 0.9982) and a limit of detection of 7 µM. Biosensor stability was evaluated throughout 15 days, and it exhibited 88.22% of the initial response. The amount of catechol standard recovered post analysis varied between 87.50% and 96.00%. Moreover, the biosensor was able to detect phenolic compounds in a real sample, and the results were in accordance with standard spectrophotometric assays. Therefore, the innovatively-designed biosensor hereby proposed is a promising tool for phenolic compound detection and quantification when environmental contaminants are concerned.

A new strategy for the construction of a polyphenol oxidase carbon paste biosensor for paracetamol detection is reported. The eggplant (Solanum melongena) was processed to collect the polyphenol oxidase as an enzyme that was incorporated in the carbon paste sensor construction. The constructed sensor displayed high sensitivity and good selection for paracetamol detection and recognition. Optimized conditions included pH 6.0 (highest activity), pH 7.0 (highest stability), pulse amplitude of 50 mV, and 15% of vegetable extract per carbon paste. The sensor displayed a linear range from 20 to 200 µM, with a detection limit of 5 µM. Application of the sensor to paracetamol determination in tablet and oral solutions have shown satisfactory results. The efficiency of the method showed very good repeatability ranging between 1.26 and 1.72% relative standard deviation for interday analysis, while recoveries for paracetamol varied between 97.5 and 99.8% for the voltammetric determination. The strategy for a simple, low cost, and efficient eggplant polyphenol oxidase sensor showcased in this work provides an opportunity for the detection of other phenolic compounds in various matrices.

The vegetable kingdom is a wide source of a diverse variety of enzymes with broad biotechnological applications. Among the main classes of plant enzymes, the polyphenol oxidases, which convert phenolic compounds to the related quinones, have been successfully used for biosensor development. The oxidation products from such enzymes can be electrochemically reduced, and the sensing is easily achieved by amperometric transducers. In this work, the polyphenoloxidases were extracted from jurubeba (Solanum paniculatum L.) fruits, and the extract was used to construct a carbon paste-based biosensor for pharmaceutical analysis and applications. The assay optimization was performed using a 0.1 mM catechol probe, taking into account the amount of enzymatic extract (50 or 200 μL) and the optimum pH (3.0 to 9.0) as well as some electrochemical differential pulse voltammetric (DPV) parameters (e.g., pulse amplitude, pulse range, pulse width, scan rate). Under optimized conditions, the biosensor was evaluated for the quantitative determination of acetaminophen, acetylsalicylic acid, methyldopa, and ascorbic acid. The best performance was obtained for acetaminophen, which responded linearly in the range between 5 and 245 μM (R = 0.9994), presenting a limit of detection of 3 μM and suitable repeatability ranging between 1.52% and 1.74% relative standard deviation (RSD).

Purpose: Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs) whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports the electrochemical study of a low-cost PPO-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples. Methods: In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Results: showcased that the biosensor presented good analytical features, as well as low detection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relative standard deviation was less than 5% mid-assay. Conclusion: The use of this biosensor is a reliable, low cost and useful alternative in the pharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).

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The manuscript describes the current analytical methodologies used in obtaining plant enzymes for biotechnological applications. The isolation and partial purification methods are reported, summarized in chromatographic electrophoretic techniques. The importance of these enzymes in biotechnology research, with a focus on its applications, characteristics and peculiarities, are emphasizing either. With regard to the applicability, the article brings several examples in food production, manufacturing and production of biosensors for determination of various analytes. About bioremediation, we aimed on pollutant removal of the natural environment and its conversion into less harmful products, using those plant enzymes. Industrial interests are also discussed.Keywords: biotechnology; food production; biosensing techniques; bioremediation. RESUMOO artigo descreve as metodologias analíticas atuais mais utilizadas na obtenção de enzimas vegetais para aplicações biotecnológicas. São relatados os métodos de isolamento e purificação parcial, que se resumem nas técnicas cromatográficas e eletroforéticas, enfatizando a importância dessas enzimas nas pesquisas em Biotecnologia, com foco nas suas aplicações, características e peculiaridades. No que se refere à aplicabilidade, o artigo traz diversos exemplos na produção de alimentos, na fabricação e produção de biossenssores para determinação de diversos analitos e na biorremediação, que que tem como objetivo a remoção de poluentes do ambiente natural e a sua conversão em produtos menos prejudiciais, utilizando, para isso, as enzimas vegetais. Interesses industriais também são discutidos.Palavras-chave: produção de alimentos; técnicas biossensoriais; biorremediação.Revisão 10.14450/2318-9312.v29.e3.a2017.pp181-198 INTRODUÇÃO A Biotecnologia é o conjunto de técnicas que permitem gerar produtos de interesse econômico e social a partir de organismos vivos ou de seus componentes (1). Nas últimas décadas apresentou uma expansão de aplicações bem sucedidas em produtos e técnicas, principalmente aquelas envolvendo enzimas (2). As enzimas são consideradas catalisadores biológicos, por exercerem a função de acelerar ou mesmo possibilitar reações entre componentes químicos (3). Estão presentes em todos os sistemas biológicos, são produzidas por todos os organismos vivos e são responsáveis por vários processos metabólicos (4).As enzimas são o principal alvo da pesquisa em Biotecnologia, não apenas por seu papel crucial nos me-

Crystal habit modification of a drug substance by performing a slurry test at a temperature higher than the melting point.

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