Carlos Alberto Bastos De Maria

Peppermint antioxidants revisited

This review discusses the relationship between the chemical composition and antioxidant property of peppermint tisane and essential oil. Phenolic acids (e.g. rosmarinic and caffeic acids), flavones (e.g. luteolin derivatives) and flavanones (e.g. eriocitrin derivatives) are possibly the major infusion antioxidants. Vitamin antioxidants (e.g. ascorbic acid and carotenoids) are minor contributors to the overall antioxidant potential. Unsaturated terpenes having a cyclohexadiene structure (e.g. terpinene) and minor cyclic oxygenated terpenes (e.g. thymol), may contribute to antioxidant potential whilst acyclic unsaturated oxygenated monoterpenes (e.g. linalool) may act as pro-oxidants in essential oil. Findings on the antioxidant potential of major cyclic oxygenated terpenes (menthol and menthone) are conflicting. Antioxidant behaviour of aqueous/organic solvent extracts and essential oil as well as the effect of environmental stresses on essential oil and phenolic composition are briefly discussed.

Glicídios no mel

A review about composition, origin and importance of carbohydrates in honey is presented. Fructose and glucose are the major carbohydrates, ranging from 65-85 % of the total soluble solids. Other minor carbohydrates, chiefly di- and trisaccharides, have been also identified. Fructose, glucose and sucrose are mainly originated from nectar. Oligosaccharides are mainly formed by trans-a-D-glucosylation reactions catalysed by honeybee a-D-glucosidase. The profile of carbohydrates can be useful for the identification of the brazilian region in which honey was produced and may also be useful for testing brazilian honey authenticity.

Compostos voláteis em méis florais

A review about origin, composition and importance of volatile compounds in floral honeys is presented. Hydrocarbons, aromatic components, acids, diacids, terpenoids, ketones, aldehydes, esters and alcohols have been found in honey aroma of different botanical origin. Cis-rose oxide has been proposed as an indicator for Tilia cordata honey. Citrus honeys are known to contain methyl anthranilate, a compound which other honeys virtually lack. Linalool, phenylethylalcohol, phenylacetaldehyde, p-anisaldehyde and benzaldehyde are important contributors for the aroma of different unifloral honeys. Both isovaleric acid, gama-decalactone and benzoic acid appears to be important odourants for Anarcadium occidentale and Croton sp. honeys from Brazil. The furfurylmercaptan, benzyl alcohol, delta-octalactone, eugenol, phenylethylalcohol and guaiacol appear to be only relevant compounds for Anarcadium occidentale. The vanillin was considered an important odourant only for Croton sp..

Métodos para análise de ácido clorogênico

This paper describes the analytical methods for determination of total chlorogenic acid (CGA) and their individual isomers. Spectrofotometric methods are adequate for total CGA analysis in green coffee but they can provide inflated results for coffee products. High pressure liquid chromatography (HPLC) with gel permeation column and ultraviolet (UV) monitoring is adequate for the simultaneous analysis of total CGA, alkaloids and sugars in coffee products. HPLC-UV-reversed phase is a simple, rapid and precise method for the determination of the individual isomers of CGA. Gas chromatography (GC) also is applied to the analysis of the individual isomers but phenolic acids need to be derivatized before analysis. Both HPLC- and GC-mass spectrometry provide an unequivocal identification of the individual isomers. The capillary electrophoresis method is simple, rapid and adequate to the simultaneous analysis of polyphenols and xanthines. Advantages and limitations of each method are discussed throughout the text.

Componentes voláteis do café torrado. Parte II. Compostos alifáticos, alicíclicos e aromáticos

This review is about the aliphatic, alicyclic and aromatic compounds (non-heterocyclic compounds) that are present in the volatile fractions of roasted coffees. Herein, the contents, aroma precursors and the sensorial properties of volatile phenols, aldehydes, ketones, alcohols, ethers, hydrocarbons, carboxylic acids, anhydrides, esters, lactones, amines and sulphur compounds are discussed. Special attention is given to the compounds of these groups that are actually important to the final aroma of roasted coffees.

Effect of light intensity and processing conditions on bioactive compounds in maté extracted from yerba mate (Ilex paraguariensis A. St.-Hil.)

This is the first report investigating the effects of cultivation, growth under full sunlight (MSL) or shade (MS), and processing (drying, sapeco and roasting) on the composition and antioxidant potential of maté. Samples were roasted (180 °C, 200 °C, 220 °C or 240 °C) for a fixed time (10 min) or roasted (10, 20, 30 or 40 min) at a fixed temperature (200 °C). HPLC/UV/MS analysis and measures of total phenolic content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition and soybean oil oxidation) were used to analyse phytochemicals. There were significant differences (p < 0.05, ANOVA/Tukey) in phenolics between MS and MSL samples following certain processing steps, but Principal Component Analysis (PCA) indicated no distinction between MS and MSL samples, suggesting that light intensity had no effect on phenolics. Caffeine increased significantly (p < 0.05) in MS samples. Temperature was more important than time, since pyrolysis of phenolics was more intense at 240 °C.