The variable having the most significant influence on the
extraction of anthocyanins from grapes by means of microwave assisted
extraction was the extraction solvent, the other variables
being less significant. With the developed method, similar recoveries
were obtained to those found with the maceration extraction
method, with a notable reduction in the extraction time from 5 h
to 5 min. Using the new method three additional acyl derivatives
can be determined in the samples analysed which are not recovered
in significant levels with the classical method to allow them
to be quantified.
The extraction system using microwaves also allows treatment
of up to 10 samples to be carried out simultaneously, thereby significantly
reducing the analysis time per sample. The reproducibility
and repeatability values for the method were adequate for
the initial target values, they were RSD < 8% and RSD < 9%,
respectively.