CHANGES OF CAROTENOIDS, COLOR, AND VITAMIN-A CONTENTS DURING PROCESSING OF CARROT JUICE

The effects of various processing methods on carotenoid, color, and vitamin A content changes in carrot juice were studied. Results showed that canning (121 degrees C, 30 min) resulted in the highest destruction of carotenoids, followed by HTST heating at 120 degrees C for 30 s, 110 degrees C for 30 s, acidification plus 105 degrees C heating for 25 s, and acidification. 13-cis-beta-Carotene was formed in largest amount during heating, followed by 13-cis-lutein and 15-cis-alpha-carotene. The formation of 13,15-di-cis-beta-carotene during canning was due mainly to conversion of 13-cis-beta-carotene, Carrot juice color turned from orange to yellow with intensive treatment. The vitamin A content decreased along with increasing temperature and heating time.