Contamination of pear concentrate by Alicyclobacillus from recirculating flume water during fruit concentrate production
Article in Press
Alicyclobacillus and viable aerobic counts were monitored at nine different production stages of pear concentrate, with the functioning of either a recirculating or a one-pass flume water system. Significantly (P < 0.05) higher levels of Alicyclobacillus were detected in the final pasteurized product (102-104°C for 90 s) when the recirculating flume water system was operational. An average of 1.19 Log10 c.f.u. ml-1 vegetative cells and 1.35 Log10 c.f.u. ml-1 endospores were recovered, whereas 0 c.f.u. ml-1 vegetative cells and endospores were detected when the one-pass flume water system was operational. Alicyclobacillus levels did not differ significantly (P > 0.05) in condensate water during the functioning of the two flume water systems, with 1.81 Log10 c.f.u. ml-1 vegetative cells and 1.01 Log10 c.f.u. ml-1 endospores (recirculating system) and 0.78 Log10 c.f.u. ml-1 vegetative cells and 0.42 Log10 c.f.u. ml-1 endospores (one-pass system) recovered, respectively. As a result, water treatment protocols should be established if untreated recirculating flume or condensate water is to be used in order to prevent Alicyclobacillus contamination and accumulation in the processing environment. © 2011 Springer Science+Business Media B.V.