Changes in physical and chemical parameters of the traditional portuguese product água‐mel during the production process
2012
FIGUEIRA, ANA CRISTINA | CAVACO, TERESA
Changes in physical and chemical parameters (viscosity, total soluble solids and Hunter color parameters L*, a*, b*, chroma and hue angle) of água‐mel were investigated throughout processing. Kinetic parameters for color change of heat‐processed água‐mel were monitored. A zero‐order kinetic model was applied to changes in L* and b*, while a* and C* were described using a first‐order kinetic model. The heating process changed all three color parameters (L*, a*, b*), causing a shift toward the darker colors. Parameters L* decreased, while a*, b*, C* and hue angle (°h) increased during heating. Regarding changes in total soluble solids and in apparent viscosity, both fitted first‐order kinetics. A direct relationship was found between the changes in these two parameters. The increase in both total soluble solids and viscosity affected a*, b* and C*. In addition, a flow diagram for the Portuguese água‐mel production process has been established. PRACTICAL APPLICATIONS: The results of this work have practical uses in the standardization of água‐mel production process. In addition, an instrumental method for color determination, using Hunter color parameters a*, b* and chroma, is suggested for the determination of the production heating time.
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