Written Paper

Microbiological quality of flours  [1993]

Richter, K.S. (Central Flour Milling Laboratory, Omaha, NE) Dorneanu, E. Eskridge, K.M. Rao, C.S.

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Over 4,000 wheat flour samples were tested according to FDA/BAM methods for Salmonella and Escherichia coli in addition to yeast and mold, aerobic plate count (APC), and coliform most probable number (MPN) counts. The data were analyzed statistically based on flour type-hard red winter (HRW), soft red winter (SRW), spring (SPG), or durum (DUR)-and season of milling production. SRW had the highest mold count (log10 3.06 cfu/g) and DUR the lowest (log10 2.85 cfu/g). SPG had the highest yeast count (log10 2.27 cfu/g) and SRW the lowest (log10 2.07 cfu/g). Highest APCs were found in DUR (log10 4.24 cfu/g), whereas the lowest were in SRW (log10 3.83 cfu/g). Of the samples tested, 12.8% were E. coli positive and 1.3% were Salmonella positive with the highest frequency of each pathogen occurring in the fall and winter months, respectively. The lowest E. coli frequency occurred during spring, whereas Salmonella had the lowest incidence in summer. The highest percentage of E. coli positives was observed in DUR (17%), and the lowest was observed in HRW samples (6.7%). The highest percentage of Salmonella positives existed in SRW (2.3%) and the lowest in DUR flour samples (0.3%). From the data, 95% confidence limits of 5,700 cfu/g for mold, 110,000 cfu/g for APC, and 150 MPN/g for coliforms were determined for all wheat flours

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Cereal foods world (USA)

ISSN : 0146-6283