The determination of glycyrrhizin in selected UK liquorice products.

The glycyrrhizin contents of 42 samples of liquorice-containing confectionery, health products and raw materials have been determined by a standard (AOAC) HPLC technique. Confectionery levels ranged between 0.26 and 7.9 mg g-1, whilst contents in health products were 0.30-47.1 mg g-1, the highest values being measured for throat pearls. Six geographically diverse samples of liquorice root contained similar (22.2-32.3 mg g-1) glycyrrhizin contents. Highest levels of glycyrrhizin were found in liquorice block (44-98 mg g-1) and extract powder (79-113 mg g-1). These analyses enable a mean daily intake of glycyrrhizin to be calculated for the UK. The figure (1 mg) is lower than those reported for the US and Belgium (3 and 5 mg, respectively). The significance of the levels of glycyrrhizin in UK confectionery, and the estimated daily exposure thereto, is discussed in the context of existing data on liquorice-induced toxicity.