Carotenoid retention and vitamin A value in carrot (Daucus carota L.) prepared by food service

The objective of this work was to study the influence of different methods of food preparation routinely used by catering and food services (in large quantities) on the stability of alpha-carotene, beta-carotene and total carotenoids in carrots. Also, the values of vitamin A were evaluated. The methods of preparation studied were: raw shredded, steam cooking, water cooking with pressure, water cooking without pressure and moist/dry cooking. The quantification of alpha and beta-carotenes was carried out by high-performance liquid chromatography (HPLC), using a reverse phase column (RP-18) with methanol: acetonitrile: ethyl acetate (80:10:10) as the mobile phase and a UV-Visible detector. Total carotenoids were quantified spectrophotometrically at 449 nm. The results showed a retention ranging from 56.0 to 89.1% for the carotenoids, with the moist/dry cooking causing the greatest losses in alpha and beta-caroten. Considering the type of utensils used, the time and temperature, it was concluded that water cooking without pressure was best for reducing losses of carotenoids in carrots prepared by food service. Despite considerable losses in vitamin A value, carrots subjected to routine preparation methods by catering and food services remain a rich source of provitamin A. The methodology developed in this study is now being applied to carotenoid analysis in other vegetables prepared in large quantities. (C) 1998 Elsevier Science Ltd. All rights reserved.