Transfer of natural and artificially inoculated microorganisms from orangefruit to fresh juice during extraction

Transfer of natural and inoculated microorganisms from fruit to fresh orang e juice was quantified during extraction. The influences of test organisms and inoculation levels on the transfer were also evaluated. About 1.7-2.6% of total aerobic organisms and 2.3-2.6% of aciduric organisms of washed ora nges were introduced to the fresh juice during extraction. Approximately 1. 3-9.9% of Escherichia coli and 2.7-8.9% Lactobacillus plantarum were recove red in juice extracted from artificially inoculated fruit. No significant d ifference (P greater than or equal to 0.05) in transfer was found with the variance of cutter size or strainer tube. Furthermore, the type of test cul tures. E. coli or L. plantarum, used for inoculation did not significantly affect the results when an identical broth was used for cell resuspension. In general, microbial levels detected in fresh juice were 90-99% (or 1-2 lo g) lower than levels found on fruit. (C) 2001 Academic Press.