In short, the C. moschata ‘Menina Brasileira’ pumpkins showed
good concentrations of a-carotene and all-trans-b-carotene, with
a lower quantity of f-carotene, violaxanthin and lutein, and the
C. maxima ‘Exposição’ pumpkins had the all-trans-b-carotene as
the major carotenoid, with good concentrations of lutein and violaxanthin.
The major carotenoids, which in the case of this present
study were the pro-vitamin carotenes, had relatively high retentions
after the production of the pumpkin purees. A light grade
of isomerisation of b-carotene was detected, with low concentrations
of cis-isomers of b-carotene in both purees. After 180 days
of storage, no significant changes in the contents of these compounds
were noted. Xanthophylls, as lutein and violaxanthin, were
more affected than the carotenes, with significant losses (P 6 0.05)
during processing and storage of the pumpkin purees. Although
these compounds are not precursors of vitamin A, the vitamin
A-inactive carotenoids are being increasingly valued due to their
action against degenerative and cardiovascular diseases, and certain
types of cancers (Azevedo-Meleiro & Rodriguez-Amaya,
2007). New studies which investigate mechanisms of the stability
of carotenoids in food matrix of pumpkin puree, the use of antioxidants,
or which involve alternative technologies for conventional
heat treatment, such as high pressure and the pulsed electric field,
are important to improve the retention of these compounds in
products such as carrots or pumpkin purees, or other vegetables
rich in carotenoids.