Carotenoids and color of fruit juice and milk beverage mixtures

Seventeen commercially available, "ready to drink" fortified beverages consisting of mixtures of fruit juices and milk were analyzed to evaluate their carotenoid profile (including their Z/E stereoisomers) and color during their commercial shelf life. Lightness (L*) was found to be correlated with the content of milk in the mixtures (r= 0.649) whereas red-yellow colors were correlated with the contents of alpha-carotene, beta-cryptoxanthin, and beta-carotene supplied by the fruit. The beverages stored under refrigeration (4 +/- 2 degrees C) showed higher luminosity (L*) and higher saturation of color (C*) and yellowness (b*). Differences (P < 0.05) in the levels of carotenoids were found among the beverages. Common fruits such as apple, lemon, pear, strawberry, kiwifruit, pineapple, and banana were low in carotenoids. However, orange, apricot, mango, and peach contributed significantly (P < 0.05) to increasing beta-cryptoxanthin and beta-carotene concentrations. Passion fruit supplied zeta-carotene, and the presence of carrot increased the levels of alpha-carotene and beta-carotene. Conversion of all-Ebeta-carotene and beta-cryptoxanthin to their Z isomers took place in 8 of the 17 samples containing alpha-carotene and in 9 of the 13 samples containing beta-cryptoxanthin, respectively, which resulted in some loss of provitamin A activity and nutritional value.