Variation in Carotenoid Composition in Carrots during Storage and Cooking

Abstract

High-performance liquid chromatography (HPLC) was applied to determine the carotenoid composition of carrots during storage and cooking. Analyses were conducted immediately after harvest and 1, 2, 4, and 8 weeks after harvest. During the course of the storage, the carotenoid levels generally decreased, and this decrease was found to be greater during the first week for β-carotene (all-trans-β-carotene) and lutein, and during the second week for α-carotene. Additionally, the amount of the α- and β-carotenes in carrot leaves changed slightly within the first 2 weeks of harvest when stored at 4℃. Specifically, the level of lutein, the main component of carrot leaves, increased from 233.8±11.7 to 346.2±26.7 ㎍/g DW during the first 2 weeks. In addition, the change in carotenoid contents was observed during the home-processing of one Korean cultivar. Carrots fried in oil showed the highest amount of β-carotene (164.3±6.6 ㎍/g DW) and α-carotene (50.1±0.4 ㎍/g DW), while carrots that were prepared by sauteing, pressure-cooking in water and microwaving had the second highest levels. The greatest loss of in carotenoids occurred in response to boiling in water containing 1% NaCl, braising and baking. The content of lutein increased slightly after boiling in water containing 1% NaCl (9.3±0.4 ㎍/g DW), while a loss in lutein occurred after preparation using other home-processing methods. A cis-isomer of all-trans-β-carotene, 13-cis-β-carotene, was present in detectable amounts in all processed samples, but not in raw roots. Another isomer, 9-cis-β-carotene, was detected in carrots that were prepared by boiling, frying and pressure-cooking.