[Beta-carotene isomerization in various food products].

The technique of division both quantitative definition a trans- and two cis-beta-carotene in the foodstuff, not containing an alpha-carotene is developed. Division is carried out by Open-chromatography on aluminium oxide by system acetone-hexane from 0 to 3% of acetone in hexane (ml/ml) with an interval of 0.25%. Using the developed technique, it is carried out determination trans- and cis-beta-carotene in foodstuff, past thermal processing (tomato juice, tomato paste and the products enriched with carotene (milk sterilized and dry, bread, oil vegetative). In the investigated products from 20 to 45% beta-carotene was in cis-from, that considerably reduces biological value of a product at an estimation in terms of retinol-equivalent.