Abstract
Network reconstruction (NR) has proven to be useful in the detection and visualization of relationships among
the compounds present in a Port wine aging data set. This view of the data provides a considerable amount of information with
which to understand the kinetic contexts of the molecules represented by peaks in each chromatogram. The aim of this study was
to use NR together with the determination of kinetic parameters to extract more information about the mechanisms involved in
Port wine aging. The volatile compounds present in samples of Port wines spanning 128 years in age were measured with the use
of GC-MS. After chromatogram alignment, a peak matrix was created, and all peak vectors were compared to one another to
determine their Pearson correlations over time. A correlation network was created and filtered on the basis of the resulting
correlation values. Some nodes in the network were further studied in experiments on Port wines stored under different
conditions of oxygen and temperature in order to determine their kinetic parameters. The resulting network can be divided into
three main branches. The first branch is related to compounds that do not directly correlate to age, the second branch contains
compounds affected by temperature, and the third branch contains compounds associated with oxygen. Compounds clustered in
the same branch of the network have similar expression patterns over time as well as the same kinetic order, thus are likely to be
dependent on the same technological parameters. Network construction and visualization provides more information with which
to understand the probable kinetic contexts of the molecules represented by peaks in each chromatogram. The approach
described here is a powerful tool for the study of mechanisms and kinetics in complex systems and should aid in the
understanding and monitoring of wine quality.
