PROPERTiES OF CAROTENOID PIGMENTS EXTRACTED FROM YELLOW CARROT AND PUMPKIN AS A FOOD COLORANTS

Document Type : Original Article

Authors

Food Science Department, Faculty of Agriculture, Ain Shams University, Shobra EL-Kheima, Cairo, Egypt.

Abstract

Carotenoids from yellow carrot (Oaucus carota L.) and pumpkin (Cucurbita
spp.) were extracted, identified by TLC and HPLC. The adsorption of concentrated
yellow pigment to solid matrixes (lactose, dextrin, flour, starch and skim milk) was
studied. The effects of pH and temperature on the pigments were evaluated and the
thermal stability of pigments was determined. The extracted yellow pigments were
used for colouring hard candy, noodle and glazing jelly as healthy food products.
The concentration of carotenoids in yellow carrot and pumpkin was 148.58
and 126.49 mg/100g, respectively. The identification results by TLC which confirmed
by HPLC showed five fractions of carrot carotenoids. They were lutein (5.49%),
cryptoxanthin (8.24%), a-carotene (39.56%), f3-carotene (44.51 %) and canthanthin
(2.20%). On the other hand four peaks were appeared in case of pumpkin carotenoids
namely isozeaxanthin (4.42%), zeaxanthin (5.76%), f3-carotene (57.58) and bixin
(32.24%). The obtained results proved that, the best carrier for adsorption of carrot
carotenoids was starch followed by lactose, while lactose was the most effective
adsorpant for carotenoids extracted from pumpkin followed by flour. The tested
carotenoids exhibit good stability to heat and the highest retention rate of carotenoids
for carrot and pumpkin was observed at pH 7.0 while the lowest retention rates were
at pH 2.0 and 9.0. Addition of 0.39% carotenoid pigments extracted from carrot as a natural
colorants to noodle prepared from wheat 72% extraction and 0.13% carotenoids
pigment to glazing jelly and hard candy were the best treatments and improved the
sensory qualities as indicated by panelists. Results suggest that carotenoids could be
successfully utilized as natural coloring agents for the purpose of making some
healthy food products.

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