Numerous beverages, such as multivitamin juice and sports drinks, are enriched with vitamins. These beverages may not be listed on a label as "enriched" or "fortified" with a particular vitamin supplement unless the vitamin is present in "significant amounts", which are defined in Annex XIII to Regulation (EU) No 1169/2011. For beverages, this amount is set at a minimum of 7.5 % of the NRV (nutrient reference values) per 100 ml or 15 % of the NRV per portion for individual portions.
Quantities recommended for the daily dietary intake of vitamins:
Determination of the content of provitamin A
Suitable for non-alcoholic beverages, juices
Carotenoids present in the juice sample are precipitated with the Carrez reagent. Interference substances remain in solution and are decanted. The Carrez precipitate is extracted with tetrahydrofuran and acetone followed by photometric determination. The extract is analyzed by means of HPLC for precise analysis of the carotenoids.