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ABSTRACT. The peels of avocados, like other fruit peels, are commonly discarded, not knowing their potential use. In order to reuse avocado peel, the chemical and mineral compositions, total phenolic and flavonoid contents as well as antioxidant activities have been investigated by DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP(ferric-reducing antioxidant power) methods in in natura and dehydrated avocado peel. Dehydrated avocado-peel tea was manufactured and the antioxidant activity was evaluated, as well as their flavonoid and phenolic compound contents, and compared with other teas marketed. Avocado peel, especially dried avocado peel, contains major phenolic compounds (10,848.27 ± 162.34 mg GAE kg ) and phenolic and flavonoids contents highest than apple tea. The avocado-peel tea showed good antioxidant activity and had good acceptability by sensory analysis as a promising product.Keywords: avocado, fruit peels, DPPH, FRAP, sensorial analysis, functional foods.Uso da casca do abacate (Persea Americana)na formulação de chá: um produto funcional contendo compostos fenólicos e atividade antioxidante RESUMO. Cascas de frutas são comumente descartadas, assim como cascas de abacate, por desconhecimento do seu potencial uso. A fim de reutilizar a casca de abacate, determinou-se a composição química e de minerais, conteúdo de fenólicos totais e de flavonoides, bem como atividades antioxidantes por ensaios de DPPH (1,1-difenil-2-picrilhidrazil) e FRAP (poder antioxidante por redução do ferro) nas cascas in natura e desidratada. Formulou-se um chá com a casca de abacate, avaliou-se sua atividade antioxidante, bem como conteúdo de fenólicos e flavonoides e comparou-se com chás comercializados. Os resultados mostram que na casca de abacate desidratada contém compostos fenólicos (10.848,27 ± 162, ) e flavonoides (1.360,34 ± 188, ). O chá da casca de abacate desidratada apresentou atividade antioxidante por DPPH (1954DPPH ( .24 ± 87.92 e 2518.59 mg ET L -1 ) superior ao chá de maçã, assim como maior conteúdo de fenólicos e flavonoides. O chá de casca de abacate apresentou boa atividade antioxidante e boa aceitação por análise sensorial, mostrando ser um produto promissor.Palavras-chave: abacate, casca de frutas, DPPH, FRAP, análise sensorial, alimento funcional.

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A 2 3 factorial design with center point in triplicate was used to evaluate the application of different enzymes in extraction of sunflower oil, comparing its quality with the oil obtained by conventional methods (solvent and pressing) in relation to antioxidant capacity, phytosterol and tocopherol contents, and fatty acid composition. Three enzymes were used; Pectinex Ultra SPL, Celluclast 1.5 L and Alcalase 2.4 L; and three factors were evaluated: enzyme concentration, sample/water ratio and extraction time. Enzymatic aqueous extraction produced oil with better quality in relation to some of the evaluated parameters: highest antioxidant capacity against peroxyl radicals (371 µmol Trolox g −1 of oil), total phytosterols (183 mg 100 g −1 of oil) and omega-3 fatty acid content, as well the lowest content of saturated fatty acids. The application of enzymes in sunflower oil extraction represents an environmentally friendly methodology, free of toxic solvent residues and providing a final product of high quality.

A fast, easy lipid extraction method using low-toxicity solvents is developed in this study for oilseed samples rich in polyunsaturated fatty acid.

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The alkaline hydrolysis of a series of homologous reactants constituted by two reactive centers bridged by a methylene spacers chain, the 1,n-bis(2-azidepyridinium)alkanes (n = 3, 4, 5, 6, and 8), is investigated. The reaction under pseudo-first-order condition was followed by ultraviolet-visible spectrophotometry. The presence of clear isosbestic point suggests the absence of stable intermediates. However, the intermediates 1-(2-azidepyridinium), n-(2-pyridone)alkanes (monocationic compounds), were isolated and characterized as well the reaction end products 1,n-(2-pyridone)alkanes (noncharged compounds). The kinetic analysis fitted to a two-step consecutive reaction, where the k 1 /k 2 values demonstrate the larger reactivity of the first step over the second one, especially for shorter bridged reactants. The OH − reaction order is one for each step. Although Debye-Hückel law was obeyed, the experimental point at ionic strength zero is much higher than the extrapolated one. In addition, the k 1 values substantially decrease as KCl is added especially for shorter homologous whereas the effect on k 2 is almost negligible. Simple charge density effects as a function of the spacer's length do not explain the observations. On the other hand, from the pronounced anion selectivity inhibition effects on k 1 for the shorter derivatives, the existence of an equilibrium involving a conformer, a "sandwich-type" complex with the OH − between the two pyridinium rings, with an "open-stretched" conformer is proposed. For short-bridged reactants, the complex conformer