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Efeito da granulometria e da embalagem na sorção de água pelo café torrado e moído
| Content Provider | Semantic Scholar |
|---|---|
| Author | Baptestini, Fernanda Machado |
| Copyright Year | 2011 |
| Abstract | BAPTESTINI, Fernanda Machado, M.Sc., Universidade Federal de Vicosa, June 2011. Effect of granulometry and packaging on water sorption by roasted and ground coffee. Adviser: Paulo Cesar Correa. Coadviser: Paulo Roberto Cecon and Nilda de Fatima Ferreira Soares. The objective of this study was to evaluate the effect of granulometry and types of packaging on the water sorption by roasted and ground coffee. Arabica coffee grains were utilized with an initial water content of 0.1234 kgw kgdm, roasted until the medium roast point, with a weight loss of 17%, in wich four granulometric levels were established: whole grains and thick, medium and thin granulometries. To obtain the water sorption isotherms and the thermodynamic properties, different conditions of temperature and relative humidity were analyzed, ranging between 25 to 30 °C and 0,3 to 0,8 (decimal), respectively. In the storage stage, roasted and ground coffee in the above specified granulometries were packaged with two different types of films: LDPE/PP (Package 1) and PET/metalized BOPP (Package 2), and stored in a BOD chamber at 25 °C. Every 30 days, were performed the following analysis: moisture content, water activity, unitary density, color evaluation and sensorial analysis. Copace model was the one that better represented the hygroscopic equilibrium for sorption in roasted coffee, for all granulometric levels; the equilibrium moisture content of roasted coffee is directly proportional to the relative humidity of ambient air and decreases when increasing the temperature for a relative humidity value; with the reduction in moisture content, the energy released by product water adsorption increases, represented by integral isosteric heat of sorption values; by reducing the moisture content, values of differential entropy of adsorption increase, and for the same moisture content, the differential entropy for roasted coffee in thin granulometry was higher than for the coffee in medium and thick granulometry, due to a higher specific surface; the theory of enthalpy-entropy compensation can be satisfactorily applied to the sorption phenomenon, being |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.locus.ufv.br/bitstream/handle/123456789/3601/texto%20completo.pdf;sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
