COLIFORM CONTENT OF FROZEN BLANCHED VEGETABLES PACKED IN THE UNITED STATES

Abstract

A total of 575 packages of frozen blanched vegetables representing 17 products packed in 24 factories located in 12 states were examined for numbers and kinds of coliforms. The organisms were recovered from over 90% of the samples with the average counts of total coliforms being over 100 per g. Thirty‐seven percent were positive for fecal coliforms (FC) using a 44.5°C incubation, with all products except broccoli yielding an average count of less than 50 per g. Escherichia coli was recovered from only 29% of the FC‐positive samples. Other species which were responsible for a positive fecal coliform test were Klebsiella pneum oniae, Enterobacter cloacae, E. agglomerans, E. aerogenes, and Citrobacter freundii. Incubation at 45.5°C eliminated only C. freundii. Fecal coliforms in vegetables negative for E. coli may be the result of raw vegetable transmission to processing equipment followed by culture development and transfer to foods being processed.