Carotenoids, color, and ascorbic acid content of a novel frozen-marketed orange juice.J Agric Food Chem. 2007 Feb 21; 55(4):1347-55.JA
A recently developed food, the so-called ultrafrozen orange juice (UFOJ), has been characterized in terms of carotenoid pigments, ascorbic acid, and color. The juice, obtained from Valencia late oranges, is frozen immediately after the squeezing of the oranges, which makes it a product showing good organoleptic and nutritional quality. In relation to the carotenoid profile, it was observed that the 5,6-epoxy carotenoids violaxanthin and antheraxanthin (specifically (9Z)-violaxanthin and (9Z)- or (9'Z)-antheraxanthin), were by far the major pigments and that dihydroxycarotenoids predominate over monohydroxycarotenoids. As far as color was concerned, it was seen that there were little differences among the juices analyzed. The hue of the samples, ranging from 77.19 degrees to 80.15 degrees and from 79.99 degrees to 83.04 degrees depending on the kind of instrumental measurement, and their chroma (ranging from 63.06 to 72.25 and from 44.40 to 58.38) revealed readily that the juice surveyed exhibited a deep orangeish coloration, the color coordinate best correlated with the total carotenoid content being b*. The levels of ascorbic acid ranged from 332.64 to 441.44 mg/L, with an average content of 391.06 +/- 28.86 mg/L.
