Transfer of caesium and potassium from Japanese apricot (Prunus mume Sieb.et Zucc.) to Japanese apricot liqueur (Ume liqueur)

The potential contamination with radionuclides released by the Fukushima Daiichi Nuclear Power Plant Accident following the great east Japan earthquake and tsunami in March 2011 of agricultural products and processed foods derived from them is a matter of on-going concern. The stable Cs-133 is a useful indicator for predicting the behaviour of radioactive Cs, and potassium (K) is a congener of Cs. In this study, the distribution of Cs-133 and K in Ume fruit, and the transfer of Cs-133 and K from Ume fruit to Ume liqueur, were investigated. The concentrations of Cs-133 and K in Ume fruit were highest in the skin, followed by the kernel or flesh, and then the pit. About 80% of Cs-133 and K in all Ume fruits was distributed in the flesh. The transfer ratios of Cs-133 and K from Ume fruit to Ume liqueur were similar among all cultivars after 3 months, and they were similar to those of organic acids. The food retention factor (Fr=weight of Cs-133 in Ume liqueur/weight of Cs-133 in Ume fruit) was ca. 0.8, and the processing factor (Pf=concentration of Cs-133 in Ume liqueur/concentration of Cs-133 in Ume fruit) was 0.2-0.3. From the present study, the radioactivity of Ume liqueur would be below the legal limit if made using Ume fruits within the legal limit, thereby confirming the safety of Ume liqueur. Copyright (C) 2016 The Institute of Brewing & Distilling.