Occurrence of patulin in the commercial processing of apple juice

Patulin, a mutagenic and genotoxic secondary metabolite, is produced in app les by several fungi, of which Penicillium expansum Link is the most signif icant. The importance of removing contaminated apples from the initial proc essing line during apple juice production was studied during three consecut ive seasons. Mean patulin concentration in non-processed apples over the th ree seasons was 2010 +/- 949 ng g(-1). The decrease in patulin concentratio n to 440 +/- 253 ng g(-1) after an initial water wash step was followed by further reduction to 200 +/- 183 ng g(-1) (P < 0.05) after the removal of r otten and damaged apples. A further study was undertaken to determine the e ffects of processing on patulin concentrations in apple juice. Composite sa mples were independently withdrawn at four sequential stages during manufac ture, namely, pre-concentration, depectinization/charcoal/ultra-filtration, passage through a resin-based absorber, and final concentration. During th e preconcentration stage (pasteurization), a statistically significant (P < 0.0001) decrease in the mean Fl expansum count from 4.07 to 0.79 log(10) c olony forming units (cfu) ml(-1) accompanied a significant increase (P < 0. 05) in patulin concentration from 105 +/- 44 ng ml(-1) to 165 +/- 49 ng ml( -1). These results were probably due to the higher temperature and total so lids concentration (Brix), respectively, during pasteurization. The combine d depectinization/charcoal/ ultra-filtration stage yielded a significant de crease in mean patulin concentration from 110 +/- 35 ng ml(-1) to 75 +/- 18 ng ml(-1) (P < 0.05), which was probably due to the adsorption of patulin on the activated charcoal. No further removal of patulin occurred during th e remainder of the juicing process.