Changes in beta-carotene content and beta-carotene isomer composition in sweet potato during storage

The change of cis-trans-beta-carotene content during storage of seven diffe rently colored sweet potato cultivars was investigated by using high perfor mance liquid chromatography (HPLC). 'Benihayato' had the highest beta-carotene content at harvest, followed by 'Healthy Red' and 'Kenroku'; 'Beniaka', 'Benikomachi', 'Kokei 14' and 'Beni azuma' had low beta-carotene content. beta-Carotene content in 'Benihayato' increased for 50 days after storage b ut decreased gradually afterward. Levels in 'Healthy Red' and 'Kenroku' ten ded to increase slightly during storage, whereas the levels in 'Beniaka' 'B enikomachi', 'Koukei 14' and 'Beniazuma' changed little during storage. At I harvest, levels of 9-cis-beta-carotene were considerably lower than were those of 13-cis and 15-cis-beta-carotenes.