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Co-products from the juice processing of guava (CG), mango (CM) and barbados cherry (CB) were investigated with a view to their exploitation as a potential source of natural antioxidants. The ethanolic extracts were analyzed for total extractable phenolic content (TEP), DPPH radical scavenging activity (RSA-DPPH), ferric reducing antioxidant power (FRAP) and antioxidant activity in relation to the β-carotene/ linoleic acid system. The TEP levels in the CG, CM and CB extracts were (24.15 ± 1.59), (44.18 ± 1.73) and (49.21 ± 3.70) mg GAE/g extract, respectively. The CM extract showed higher DPPH, FRAP and antioxidant activity in the β-carotene/linoleic acid system. The data revealed a positive linear correlation between TEP, RSA-DPPH and FRAP (r 2 = 0.85 − 0.98); however, the β-carotene/linoleic acid system (r 2 = 0.01 − 0.26) shows low correlation with the TEP levels and other assessment systems. The results suggest that co-products generated from the juice processing of the studied fruit have promising use as a natural source of antioxidants.

This study assessed the antioxidant activity of Moringa oleifera Lam. extracts on the oxidative stability of fish oil subjected to conditions of accelerate storage (16 days at 60C) compared with synthetic antioxidants such as tertiary butylhydroquinone (TBHQ) and butylated hydroxytoluene (BHT). Fish oil samples were added with leaves, flowers and seed pod extracts and evaluated for peroxide, hydroperoxides, anisidine and conjugated diene values. Changes in trans‐fatty acid and aldehyde content were also assessed. The addition of Moringa extracts delayed the oxidation of fish oil; in particular, extracts of leaves showed a higher antioxidant activity when compared with TBHQ and BHT, considering peroxide and hydroperoxide levels. To control the formation of secondary oxidation compounds, synthetic antioxidants were most effective; however, leaf extract showed the highest protective effects of polyunsaturated fatty content in fish oil. Results indicate that the extract of M. oleifera leaves is an effective antioxidant to prevent oxidation in fish oil. Practical Applications Antioxidants are important ingredients in food processing to retard, reduce or prevent oxidative deterioration. Synthetic antioxidants are widely used in the food industry; however, their utilization has been questioned because of toxicity. Therefore, there is a growing interest in the use of natural antioxidants to reduce or replace the synthetic antioxidants in edible oils. Moringa oleifera L. is a botanical specie that is well known for its rich compounds with high antioxidant activity; in particular, its leaf extract can be used to replace synthetic antioxidants used in fish oil.

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Recebido em 12/3/09; aceito em 13/8/09; publicado na web em 8/1/10 SCREENING ANALYSIS OF WINES USING FLOW-BATCH ANALYZER, UV-VIS SPECTROSCOPY AND CHEMOMETRICS. A simple, robust, versatile, high analytical frequency method was proposed to check if a sample of wine is within the range of standards set by the manufacturer, using the UV-VIS spectroscopy, multivariate analysis and a flow-batch analyzer. Two hundred and fifty-two samples of wines were analyzed. The results from the application of Hierachical Cluster Analysis (HCA) to the matrix of the data involving all samples show the formation of fifteen types of wine. A Soft Independent Modelling of Class Analogy (SIMCA) model was constructed and used to classify the samples of the overall forecast. As a result, it is observed that the prediction was performed with a success rate of 99.2% for a confidence level of 95%. This shows that the proposed methodology can be used as an effective tool for classifying of samples of wines.Keywords: quality control of wines; flow-batch analyzer; chemometrics. INTRODUÇÃOO vinho é uma bebida simples, resultante da conversão gradual dos açúcares presentes no mosto de uvas frescas em álcool, CO 2 e energia por intermédio do levedo.1 Desta forma, vinhos de má qualidade são facilmente elaborados, bem como bastante propícios a falsificações e/ou adulterações. As falsificações e/ou adulterações de alimentos constituem crime contra a saúde pública, na medida em que são comercializados produtos ilegais, sem controle e sem fiscalização, que podem prejudicar a saúde da população, além de lesar o consumidor que paga caro por um produto de qualidade e de sonegar impostos aos órgãos governamentais. Muitos são os relatos de casos de falsificação e/ou adulterações de vinhos e, preocupadas com este problema, as indústrias produtoras tentam, a todo custo, tomar medidas que amenizem esta situação.Existe uma vasta variedade de vinhos e a forma mais comum para classificá-los corresponde ao seu aspecto visual e pigmentação característica. Porém, existem outras classificações que têm a ver com o processo de vinificação ou, ainda, quanto ao teor de açúcar. A classificação e a caracterização de vinhos vêm sendo realizadas através da utilização de alguns parâmetros como teor alcoólico, pH, acidez fixa e volátil, teor de cinzas etc.2 Para isso têm sido utilizados métodos espectroscópicos de massa, 3 de emissão óptica, 4 de espectroscopia NIR 5 e de absorção atômica em chama. 6 No entanto, a técnica analítica padrão de referência utilizada para a verificação da autenticidade de vinhos no Brasil é a cromatografia.7 Tal técnica apresenta um custo elevado de seus instrumentos e de manutenção constante, bem como requer a preparação de reagentes e soluções padrão com produção de resíduos prejudiciais à saúde e/ou ao meio ambiente, além de apresentar uma baixa frequência analítica. Uma boa alternativa para superar estes inconvenientes é o desenvolvimento de métodos analíticos que combinam o uso da espectrometria de absorção molecular UV-VIS, analisadores automá...

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