Provitamin A and carotenoid content of citrus juices

Abstract

The carotenoid content in juice of seven citrus cultivars was followed during the fruit maturation period. The analyses were performed with high-performance liquid chromatography (HPLC) procedures that are rapid and reproducible. Using these methods, isomers of cryptoxanthin as well as the carotenes were separated and determined for calculating provitamin A values. ß-Cryptoxanthin readily separated from -cryptoxanthin. The ß isomer was found to be the main source of provitamin A in citrus juice while the structure of the a form would indicate that it is nonactive. The provitamin A content of citrus juice varies with fruit cultivar. Juice of the sweet orange cultivars had the lowest provitamin A carotenoid content while that of Dancy tangerine and Robinson were intermediate. The provitamin A content of Murcott was found to be the highest among all the cultivars studied.

Review: Analysis of carotenoids in orange juice

“…At this point, before getting further into the account of the major carotenoids reported in diverse orange juices, it is important to note that the carotenoid profile of not only them, but also of most foods depends on the variety of the oranges, climatic factors, industrial processing and storage conditions, among others (Rodriguez-Amaya, 2001), as it can be observed in Table 2. Stewart (1977b) assessed the levels of some carotenoids of a series of juices from different citrus cultivars (Hamlin, Pineapple and Valencia oranges, Dancy tangerine and the hybrids Murcott, Orlando and Robinson), reporting that violaxanthin, antheraxanthin and ''cryptoxanthin'' were the major ones and that there were large differences on the vitamin A activities reported (ranging from 80 international units for Hamlin to 3195 international units for Murcott), which is a good illustration of the influence of the orange variety on the carotenoid profile.…”

Flavor and Color of Fruits as Affected by Processing

“…The major pigments in ripe oranges are three xanthophylls-cryptoxantin (red), antheraxanthin (yellow), and violaxanthin (yellow) (Stewart 1977;Nordby and Nagy 1980). Carotenes (orange) are present in lower concentrations, but make an important contribution to the coloration of the fruit (Gross 1977).…”

“…Such apparently trivial factors as the side of the tree can influence coloration. Stewart (1977) noted that juice produced from oranges grown on the north side of trees (in the northern hemisphere) produced a deeper colored juice. Color development in orange peel results from chlorophyll degradation and carotenoid biosynthesis.…”

Correlation between visual and instrumental colour measurements of orange juice dilutions: effect of the background

“…As a result of this survey, the United States Department of Agriculture (USDA) assigned 40 points out of a scale of 100 points for colour, for the commercial classification of this product. Thus, a grade A orange juice must have a colour number between 36 and 40 points, whereas grade B orange juices are those with colour numbers ranging from 32 to 35 points (Lee, 2001;Stewart, 1977).…”