Research Journal of Agricultural Science, 42 (1), 2010 517 HPLC ASSESMENT OF PROVITAMIN A CAROTENOIDS FROM CUCURBITA MAXIMA DUCH. EX. LAM. (MARIŢA CULTIVAR) FRUITS Edward MUNTEAN, Ioan ROTAR University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Romania 3-5 Calea Manastur Str., 400372 – Cluj Napoca, Romania; Corresponding author: edimuntean@yahoo.com Abstract: Carotenoids are biologically active compounds widely distributed in plants. The fruits of Cucurbita maxima Duch. ex.Lam. - Mariţa cultivar are used as forage, being valuable sources of carbohydrates and carotenoids, including provitamin A ones. This study emerged from the need for reliable data on the carotenoid content of feeds, knowing the demonstrated correlation between carotenoid intake (especially of those with provitamin A activity) and health. Meanwhile, knowing the carotenoid levels is an important task for rationally using this fruits in animal feeding. Provitamin A were completely extracted from ripe fruits of Cucurbita maxima Duch. ex.Lam. - Mariţa cultivar using methanol and acetone. High performance liquid chromatography was accomplished using a Nucleosil 120-5 C 18 column, detection, detection being made using a Waters 990 photodiode array detector. Carotenoid identification was completed based on HPLC co - chromatography with authentic standards and by comparison of the visible absorption spectra with those of reference carotenoids; quantification was based on the external standard method. The major identified provitamin A in the fruits’ mesocarp is   - carotene (15.36 g/ g dry weight); minor provitamins A are the hydrocarbons  -carotene and 15, 15’ - Z -   - carotene and the xanthophylls 5,6–epoxy--carotene, -cryptoxanthin and cryptoxanthin, all with concentrations less than 1.00 g/ g dry weight. The fruit epicarp showed a similar provitamin A pattern, with lower amounts of   - carotene (9.47 g/ g dry weight), while from the minor provitamins A, 5,6–epoxy--carotene is missing. Key words: carotenoids, provitamins A, chromatography, HPLC, feed, Cucurbita maxima Duch. ex.Lam. - Mariţa cultivar INTRODUCTION Carotenoids are biologically active compounds widely distributed in plants, being responsible for the yellow to orange or red color of different plant tissues. Besides natural carotenoids, synthetic ones are used as additives for animal feed, the main purposes being either to provide adequate supplies of provitamin A or the desired color to animal tissues or to derived products, such as astaxanthin to salmon, lutein and zeaxanthin to chicken (for egg yolk and skin coloration),  - carotene to cattle (for cream coloration), etc. However, natural carotenoids are preferred in their original matrix, these acting in a synergic way with other nutrients and being better accepted by animals. The increased interest in carotenoid-rich plant matrix has been mainly generated by their health-related properties. Hence, carotenoids with -ring end groups taken from the diet act as precursors for the production of retinoids in animal cells [DEMMIG-ADAMS – 2002; Fraser - 2004]. Only a small number of carotenoids have provitamin A activity; from these,  - carotene have the highest provitamin A activity potential. Carotenoids acts as free radical scavengers and antioxidants in vivo, this biological function being independent of the provitamin A activity; an inverse relationship exists between the dietary intake of carotenoid- rich foods such as fruit and vegetables and the incidence of lung, breast, colon, and prostate cancers, UV-induced skin damage, coronary heart disease, cataracts, and macular degeneration [DEMMIG-ADAMS – 2002; FRASER – 2004; STAHL - 2005].