Fruit juice beverages comprising probiotic bacteria and fructooligosaccharides may be used for promoting growth of beneficial bacteria in the gut. In addition there are a plurality of phase locked loops 230a, 230b, 230c, each phase locked loop having a respective Voltage Controlled Oscillator 240a, 240b, 240c for outputting a signal. Upon solidification, the particles are removed and made available for subsequent use.