Beta-Carotene

Beta-carotene (CAS 7235-40-7, C40H56, molecular weight 536.87) is a tetraterpenoid hydrocarbon and the most important provitamin A carotenoid. It serves two distinct industrial functions: as a precursor that the body converts enzymatically to retinol, and as an orange to red-orange colouring matter approved for food use under E160a / INS 160a. Provitamin A activity is calculated on the basis that 1 IU of vitamin A corresponds to 0.6 µg of beta-carotene, so pure beta-carotene carries approximately 1,667,000 IU of vitamin A activity per gram. Crystalline material to USP and Ph. Eur. assays 96.0 to 101.0 per cent total carotenoids calculated as C40H56, of which not less than 95 per cent is the all-trans isomer. The pure crystal is a dark red to orange-red crystalline powder melting at about 183 °C with decomposition, practically insoluble in water, sparingly soluble in vegetable oils and soluble in dichloromethane and chloroform. Because the free crystal is difficult to dose and highly oxidation-sensitive, most commercial trade is in standardised delivery forms, and Thovek supplies these alongside the crystal: 1%, 10%, 20% and 30% cold-water-soluble and cold-water-dispersible beadlets, in which micronised beta-carotene is emulsified into a modified food starch or gelatin matrix, spray dried, coated with corn starch and protected with dl-alpha-tocopherol and ascorbyl palmitate; 20% and 30% suspensions in refined vegetable oil for softgels and oil systems; and liquid emulsions for clear beverages. Beadlet grades are free-flowing red to reddish-brown spheres in a typical 40 to 100 mesh range, and disperse in cold water to give stable yellow to orange colouration without a fat carrier. Material is available in synthetic form and as natural beta-carotene from Blakeslea trispora or Dunaliella salina where a natural-origin declaration is required. Each batch is released against a certificate of analysis covering identity by UV-visible absorption and HPLC, assay of total and all-trans carotenoids, loss on drying (not more than 0.2 per cent for crystalline USP material, dried in vacuum over phosphorus pentoxide at 40 °C for four hours), residue on ignition not more than 0.2 per cent, heavy metals not more than 10 ppm, and microbiological limits. Beadlet grades carry 36 months shelf life from date of manufacture in the unopened original container at ambient temperature, protected from light, heat, oxygen and moisture. Export packing is light-tight and nitrogen-flushed, with COA, MSDS, allergen, GMO, BSE/TSE and halal/kosher documentation supplied as required.