The decaffeinated coffee market has been expanding increasingly in the last years. During decaffeination, aroma precursors and bioactive compounds may be extracted. In the present study we evaluate the changes in the chemical composition of C. arabica and C. canephora produced by decaffeination using dichloromethane. A significant change in the chemical composition of both C. arabica and C. canephora species was observed, with differences between species and degrees of roasting. Major changes were observed in sucrose, protein and trigonelline contents after decaffeination. Changes in the levels of total chlorogenic acids and in their isomers distribution were also observed. Lipids and total carbohydrates were not affected as much. The sensory and biological implications of these changes need to be investigated.

Coffee is a product consumed all around the world, Brazil being the biggest exporter. However, little is known about the difference in composition of the different brands in terms of bioactive substances. In the present study, ten of the most consumed brands of coffee in Rio de Janeiro were analyzed. Caffeine contents, trigonelline and total chlorogenic acid varied from 0.8 g/100g to 1.4 g/100g; 0.2 g/100g to 0.5 g/100g and from 3.5 g kg-1 to 15.9 g kg-1, respectively. The large heterogeneity observed in the amounts of the bioactive compounds can be attributed to different formulations of the various brands, as well as to different roasting conditions.

Se establecieron cultivos de callo de diferentes órganos de semilleros y de plantas de Rollinia mucosa propagada in vitro. La tasa de crecimiento, el tipo de callo y el patrón biosintético de lignan furoforánico estuvieron significativamente influenciados por el origen del material vegetal, el tipo de explante y los reguladores de crecimiento usados: 2,4 ácido diclorofenoxiacético, ácido naftaleneacético, 6-benziladenina, ácido giberélico, y picloram. La eficiencia de la producción de callo y de la síntesis de lignan fue marcadamente mayor en los explantes de hoja foliar en la mayoría de los medios de cultivo. La mejor biomasa se obtuvo en los medios de cultivo con picloram. En los explantes en semilleros, el ácido naftaleneacético y el ácido 2,4-diclorofenoxiacético indujeron la síntesis de epiyangambina en callos de hoja foliar y de magnolina en callos de epicotilo y petiolo. En los explantes de plantas propagadas in vitro, la síntesis de epiyagambina se indujo mediante picloram sólo en callos del tallo. Los callos de hoja foliar cultivados en 10, 4, 20,8 y 32 µM de picloram presentaron un incremento de 2 a 3 veces en las tasas de epiyagambina con respecto a los niveles detectados en la planta original.

Callus cultures were established from different organs of seedlings and in vitro propagated plants of Rollinia mucosa. The growth rate, type of callus and furofuranic lignan biosynthetic pattern were significantly influenced by the origin of the plant material, the explant type and the growth regulators used: 2,4-dichlorophenoxyacetic acid, naphthaleneacetic acid, 6-benzyladenine, gibberellic acid, and picloram.The efficiency of callus production and lignan synthesis was significantly higher in foliar blade explants in the majority of media. The best biomass was obtained on media with picloram. In seedlings explants, naphthaleneacetic acid and 2,4-dichlorophenoxyacetic acid induced epiyangambin synthesis in calli from foliar blade and magnolin in calli from epicotyl and petiole. In in vitro propagated plants explants, the synthesis of epiyangambin was induced by picloram only in calli from stem. Calli from foliar blade cultured in 10,4, 20,8 and 31,2 µM of picloram presented a two-three fold increase in epiyangambin rates with regard to levels detected in the original plant.

Nove amostras de café solúvel representativas das marcas brasileiras foram adquiridas no mercado e analisadas quanto a composição de ácidos clorogênicos, cafeína e trigonelina, através de cromatografia líquida de alta eficiência. Os isômeros dos principais grupos de ácidos clorogênicos (ACG), ou seja, ácidos cafeoilquínicos (ACQ), dicafeoilquínicos (ADICQ) e feruloilquínicos (AFQ) foram determinados. O grupo de ACQ foi predominante em todas as amostras sendo o 5-ACQ o maior componente nas amostras. Os teores totais de ACG variaram de 0,6 a 5,9g%. As amostras com baixo teor de ACG foram provavelmente aquelas obtidas de grãos submetidos a torrefação intensa. Os teores de trigonelina foram também bastante variáveis situando-se na faixa de 0,3 a 1,0g% refletindo as diferentes condições de processamento utilizadas pelos fabricantes. Com exceção das amostras descafeinadas que apresentaram resíduo de 0,065g% os teores de cafeína situaram-se em torno de 2,7g%. A menor variabilidade nos teores de cafeína deve-se a sua alta estabilidade térmica. O conhecimento da composição do café solúvel, principalmente em relação aos compostos bioativos é relevante para o direcionamento de futuros estudos e para a avaliação da contribuição do café nos efeitos biológicos específicos da dieta.

Nine Brazilian instant coffee samples were analysed for chlorogenic acids, caffeine and trigonelline using HPLC. Different isomers of chlorogenic acid (CGA) in the groups of caffeoylquinic acids (CQA), dicaffeoylquinic acids (DICQA) and feruloylquinic acids (FQA) were determined. The isomers of the CQA group were predominant in all samples with 5-CQA being the most abundant. Total CGA levels varied from 0.6 to 5.9g%. The samples with lowest CGA content were probably the ones obtained from dark roasted coffee beans. The trigonelline levels varied between 0.3 to 1.0g% reflecting the different conditions used by the manufacturers. The decaffeinated coffee retained about 0.065g% of caffeine and the majority of the other samples showed levels around 2.7g%. The small variability of caffeine within the samples was due to its resistance to the heat treatment. The knowledge of instant coffee composition is relevant to evaluate the real contribution of coffee to the biological effects of the diet.

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.

A review of heterocyclic compounds in roasted coffee is presented. The contents, precursors and sensorial properties of furans, pyrroles, oxazoles, thiazoles, thiophenes, pyrazines and pyridines are discussed. The impact heterocyclic compounds of coffee aroma are described.