RESUMO
Coffee production is the result of the relationship between local environmental conditions and coffee cultivars that grow in this place. Coffee plants develop original physico-chemical and sensory characteristics that together with the agricultural techniques practiced by growers define the terroir. The objective of this study was to describe the typicity of coffee prepared by coffee growers from seven coffee terroirs in Paraná, Brazil. The terroir categorization was based on the local latitude, longitude, altitude and annual average temperature. Coffee samples were prepared by the coffee growers according to their agricultural techniques. A multiple factor analysis (MFA) was applied to the groups of variables of the green and roasted coffee bean physico-chemical and sensory attributes. The variability in environmental conditions was sufficient to modify the green and roasted coffee bean characteristics and sensory attributes. The terroir description obtained with MFA description compared to that obtained with individual groups of variables was different among terroirs. Roasted coffee variables and sensory attributes caused the greatest differences. The individual use of these groups of variables may result in non-representative descriptions of coffee from different terroirs. Mandaguari and Ivaiporã terroirs were associated with high nitrogenous compounds content, high expansion volume and low density of roasted coffees, and the beverages showed a high turbidity and intense body. Apucarana, São Jerônimo da Serra and Ribeirão do Pinhal terroirs were associated with low lipids content, high density and low volume expansion roasted coffee, and the beverage showed intense coffee and sweet aromas and a low turbidity and body texture. In coffee from the Londrina terroir, medium nitrogenous compounds content and high sucrose and lipids contents were found. Their beverage showed a high turbidity and intense body as well as a grassy green taste and astringency. Coffee from Ribeirão Claro terroir presented high lipids and sucrose contents and low caffeine and phenolic compounds contents, and the main sensory attributes were a coffee aroma and sweet and sour tastes. In conclusion, a terroir formed by environmental conditions and agricultural techniques can produce coffee with a set of physico-chemical and sensory characteristics that define its typicity.
Assuntos
Coffea/química , Café/química , Café/classificação , Brasil , Cafeína/análise , Fenômenos Químicos , Análise Fatorial , Análise de Alimentos , Manipulação de Alimentos , Temperatura Alta , Odorantes/análise , Fenóis/análiseRESUMO
A novel and fast method based on the solid phase extraction (SPE) coupled to a flow injection system for the determination of caffeine in coffee beans was developed. The caffeine extraction of coffee beans was carried out with hot water. A C18 reverse-phase mini-column was coupled to a continuous flow manifold to carry out the on-line SPE and the quantification of caffeine from aqueous extracts. Column length, retention time, elution volume, extracting solution and injection volume were evaluated. The retention time was of 90s and the elution was carried out with 400 µL of a methanol:water mixture (25:75). The proposed on-line SPE was compared against a chloroform extraction from aqueous extracts. With the proposed method the sample preparation was minimised and the sample throughput was increased (10 determination/h) because no dilution was required. Green coffee beans and beans with different roasting degree were analyzed.