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Original articleEffect of roasting on chlorogenic acids, caffeine and polycyclic aromatic hydrocarbons levels in two Coffea cultivars: Coffea arabica cv. Catuaí Amarelo IAC-62 and Coffea canephora cv. SummaryDuring coffee roasting process, several substances may be formed or eliminated. The influence of roasting on polycyclic aromatic hydrocarbons (PAHs), caffeoylquinic acids (CQAs) and caffeine levels was studied in Coffea arabica cv. Catuaı´Amarelo IAC-62 and Coffea canephora cv. Apoata˜IAC-2258, roasted in three roasting degrees. CQAs and caffeine were determined simultaneously by HPLC-DAD, and PAHs by HPLC-FLD. Caffeine levels were higher in canephora (1486-1884 mg per 100 g) than in arabica (1110-1255 mg per 100 g) and increased up to 21% at darker roasts. Summed CQA levels were higher in green coffee (4661 and 4946 mg per 100 g) and decreased at darker roasts (234 and 377 mg per 100 g), showing no difference between the coffee cultivars studied. PAH summed levels varied from 0.052 to 0.814 lg kg )1 (arabica) and 0.108 to 0.392 lg kg )1 (canephora). No correlation was observed between roasting degree, coffee cultivar and PAH levels. Results were also analysed using hierarchical cluster analysis and principal component analysis.

Summary The influence of coffee cultivar, roasting degree and brewing procedure in the presence and transfer of caffeine and caffeoylquinic acids (CQAs) from ground roasted coffee to the brew was evaluated. Two coffee cultivars were roasted in three roasting degrees and brewed using two different procedures. Compounds were determined simultaneously by HPLC‐DAD. Caffeine levels ranged from 87.3 to 122.5 mg/100 mL for Coffea arabica cv. Catuaí Amarelo and from 123.3 to 192.0 mg/100 mL for C. canephora cv. Apoatã. The sum of CQA isomers ranged from 24.2 to 41.3 mg/100 mL for brews prepared with dark roasted coffee and from 187.7 to 295.6 mg/100 mL for light roasted ones. Brews prepared by boiling showed higher content of the compounds than the corresponding filtered ones. C. arabica cv. Catuaí Amarelo light roasted coffee brew presented the lowest caffeine/CQA ratio, regardless of the brewing procedure used, in comparison with the highest ratio of the dark boiled brews.

a b s t r a c tDuring coffee's roasting process undesirable compounds such as polycyclic aromatic hydrocarbons (PAHs) may be formed and later transferred to the brew. The influence of coffee cultivar, roasting degree and brewing procedure in the presence and transfer of four PAHs from ground roasted coffee to the brew was evaluated. Ground roasted coffees in three roasting degrees were obtained from Coffea arabica cv. Catuaí Amarelo IAC-62 and Coffea canephora cv. Apoatã IAC-2258 and their respective coffee brews were prepared by two brewing procedures (filtered and boiled). PAHs levels in the brews were determined by HPLC-FLD. At least one PAH was detected in all coffee brew samples. PAHs summed levels ranged from 0.015 to 0.105 mg/L (C. arabica brews) and 0.011 to 0.111 mg/L (C. canephora brews). The difference among the levels detected in different roasting degrees was not statistically significant, except between dark and roasted filtered brews. Coffee brews prepared with C. arabica ground roasted beans presented mean summed PAHs levels higher than the ones prepared with C. canephora, independently of the brewing procedure used. The caffeine levels in the beverages do not seem to influence the transfer.

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The daily intakes of benzoates and sorbates from selected food categories were estimated in Brazil in 1999. The Budget method was used as a first screening procedure for the estimation of the safety aspects of the maximum permitted levels of benzoates and sorbates established by the Brazilian food legislation. This screening indicated that benzoates should be further investigated. In a second step, the daily intakes of these preservatives were assessed by combining measured levels of these additives with national food consumption data derived from a household economic survey and a packaged good market survey. Benzoate and sorbate levels in soft drinks, fruit juices, margarine, yoghurt and cheese were determined by HPLC with a photodiode array detector (detection at 228 nm for benzoic acid, 260 nm for sorbic acid). The estimated intakes of benzoates and sorbates for the average consumer were below the ADIs, ranging from 0.3 to 0.9 and 0.2 to 0.3 mg kg(-1) body weight, respectively. Soft drinks were identified as the main source of benzoates representing >80% of the estimated intake.

OBJETIVO: Este estudo teve como objetivo determinar os teores de cafeína em diferentes marcas de guaraná em pó disponíveis comercialmente. MÉTODOS: A metodologia analítica utilizada envolveu as etapas de extração com água, limpeza da amostra com acetato de chumbo e determinação por cromatografia líquida de alta eficiência com detector de arranjo de diodos (200-400nm). Foram analisadas 39 amostras adquiridas nas cidades de Campinas e Ribeirão Preto, SP, entre dezembro de 2003 e janeiro de 2004. RESULTADOS: Os teores de cafeína nas amostras apresentaram grande variabilidade, situando-se na faixa de 9,52 a 36,71mg/g de pó, isso se deve, possivelmente, às diferenças de procedência e processo a que a matéria-prima foi submetida. Comparando-se com o pó de café, fonte tradicional de cafeína na dieta, verifica-se que o teor médio de cafeína encontrado no guaraná em pó, dependendo da marca considerada, pode ser até quatro vezes maior. CONCLUSÃO: Entre os consumidores de guaraná em pó esse produto pode ser considerado uma importante fonte de cafeína na dieta, e sua associação com demais produtos que contêm cafeína sugere que seu consumo deve ser controlado, uma vez que controvérsias persistem quanto à dose segura de ingestão da cafeína.

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