Pumpkin puree was prepared by mixing in Thermomix TM
(Vorverk) for 10 min at a temperature of 90C and stored at
18C until it was subjected to analyses. First, it underwent basic
analyses. In order to assay acids with the use of HPLC, the samples
were prepared according to the following procedure: fruit puree
(10 g) was diluted to 50 ml with double-distilled water and boiled
in 95C for 5 min, and clarified by centrifugation at 6000 g for
15 min. The extract was filtered through 0.45lm Millipore filters
and 20ll sample was used for HPLC analysis of organic acid