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Carotenoid content and sensory characteristics of carrot chips deep-fried at three different oils and temperatures |
A. SULAEMAN, L. Keeler, D. W. Giraud, S. L. Taylor, and J. A. Driskell. Department of Nutritional Science and Dietetics, University of Nebraska, 316 Ruth Leverton Hall, P.O. Box 830806, Lincoln, NE 68583-0806
Dietary carotenoids function as vitamin A precursors as well as likely being chemopreventive agents. Reportedly, heat treatment promotes isomerization of the carotenoids in foods, which may lower the carotenoid content. The degree of carotenoid loss may be influenced by the type of oil and the intensity and duration of heat processing. Our objective was to determine the effect of deep-frying on carotenoid content and sensory characteristics of carrot chips. Fresh jumbo carrots (Daucus carota L. var. Sativa DC) were cut into 55 mm length, peeled, and sliced into 1.5 mm thickness. The sliced carrots were steam-blanched at 100 C for 4 min, cooled, and soaked in 0.2 % sodium metabisulfite for 15 min. The chips were then deep-fried in three types of oil (canola, palm, partially hydrogenated soybean (PHSO)) and three different temperatures (165, 175, 185 C). No significant (P<0.05) differences in color, crispness, sweetness, and odor were observed in chips prepared using different oils according to trained panelists. Increasing the temperature significantly darkened the color and lowered the crispness. The carrot chips fried in PHSO at 165 C were judged the most acceptable product. The carotenoid contents of the chips ranged from 10.8-15.6 mg à-carotene, 29.0-37.2 mg -carotene, and 9.5-17.3 mg cis- -carotene per 100g chips. Frying temperature, but not oil, significantly (P<0.05) affected the carotenoid contents, with chips fried at 165 C having the highest carotenoid contents. Estimated vitamin A activity of the chips ranged from 5731 - 7490 æg RE per 100 g. The true retentions of à- and -carotene were 52.68 - 82.18 % and 53.22 - 70.77 %, respectively. These results suggest that deep-frying of carrot chips resulted in a highly acceptable product that was rich in carotenoids that are vitamin A precursors and antioxidants.
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