J Food Sci Nutr Vol 14, p 240～245 (2009) DOI: 10.3746/jfn.2009.14.3.240 Variation in Carotenoid Composition in Carrots during Storage and Cooking Chae Jin Lim 1 , Hyun Young Kim 1 , Cheol Ho Lee 1 , Yongung Kim 2 , Kyongwhan Back 3 , Jung-Myung Bae 4 , Shin Woo Lee 1 , and Mi-Jeong Ahn 1† 1 College of Life Sciences and Natural Resources, Jinju National University, Gyeongnam 660-758, Korea 2 College of Herbal Bio-industry, Daegu Haany University, Gyeongbuk 712-715, Korea 3 Department of Biotechnology, Agricultural Plant Stress Research Center, Chonnam National University, Gwangju 500-757, Korea 4 School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea 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 o C. Specifically, the level of lutein, the main component of carrot leaves, increased from 233.8 ± 11.7 to 346.2 ± 26.7 μg/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 μg/g DW) and α-carotene (50.1 ± 0.4 μg/g DW), while carrots that were prepared by sautéing, 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 μg/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. Key words: carrots, α-carotene, β-carotene, lutein, carotenoids, storage, cooking     † Corresponding author. E-mail: amj5812@jinju.ac.kr † Phone: +82-55-751-3228, Fax: +82-55-751-3229 INTRODUCTION Carrots are the roots of Daucus carota L. (Apiaceae) and an important dietary source of carotenoids such as α- and β-carotenes (provitamin A). While carotenoid pigments are essential for photosynthesis and function as attractants in some higher plant organs, their health benefits to humans and animals are becoming increas- ingly apparent (1,2). For example, there is a great deal of evidence that these pigments act as antioxidants and protect humans from serious disorders such as skin de- generation and aging, cardiovascular disease, certain types of cancer and age-related diseases of the eye, such as macular degeneration or cataracts (3-5). Indeed, the lutein extract from marigold flowers has recently been used as a supplementary nutrient to maintain the health of eyes. As a food material, carrots are usually stored in do- mestic refrigerators for several weeks and home-proc- essed using various cooking methods. However, car- otenoids are known to be labile to light or heat, oxygen and acids. Indeed, evaluation of the Japanese carrot vari- ety Kintoki revealed that 20% of β-carotene (all-trans-β- carotene) content was lost within eight weeks of cold storage, and the content was found to decrease slightly after blanching at 90 o C (6). Another study found that food processing reduced carotenoid contents in food ma- terials and changed their chemical conformation (7). Additionally, the carotenoid content was found to de- crease with increasing storage period in cooked carrots, and the 9- and 13-cis carotenoid isomers were the major components formed during storage (8). Although there have been several other reports conducted to evaluate the stability of carrots under different storage conditions, these studies do not provide much information regarding the stability of lutein or effect of various home-process- ing methods (9-11). In the present study, the stability of the major carotenoids in carrots was evaluated during