Microbiological Methods for Examination of Frozen and/or Prepared Foods

1966 ◽  
Vol 49 (2) ◽  
pp. 276-281
Author(s):  
Bernard F Surkiewicz

Abstract A method for the microbiological examination of frozen and/or prepared foods as an index to the sanitary conditions under which the food was produced and/or stored was subjected to collaborative study. The method encompasses four determinations: aerobic plate count, the MPN (most probable number) of coliforms, the MPN of E. coli, and the numbers of S. aureus. Subdivisions of custard pie filling, some inoculated with E. coli, A. aerogenes, or S. aureus, were examined by four laboratories. Statistical evaluation of the results indicated that the method gives essentially equivalent results from laboratory to laboratory. It is recommended that the method be adopted as official, first action.

1989 ◽  
Vol 72 (4) ◽  
pp. 632-637 ◽  
Author(s):  
Felicia B Satchell ◽  
Verneal R Bruce ◽  
Geraldine Allen ◽  
Wallace H Andrews ◽  
Harriet R Gerber

Abstract A microbiological survey was performed on 4 selected imported spices: black peppercorns, white peppercorns, coriander, and fennel seed. Aerobic plate count values ranged from 104 to 107 colonyforming units (CFU)/g for black and white peppercorns and from 103 to 105 CFU/g for coriander and fennel seed. Combined results of the 3-tube most probable number procedure and the API 20E kit indicated the presence of Escherichia coli in 4 test samples of black peppercorns, 1 test sample of white peppercorns, and 1 test sample of coriander. Two test samples of black peppercorns were positive for Salmonella contamination. Among the various Enterobacteriaceae isolated from the spices, Enterobacter cloacae and Klebsiella pneumoniae were found most frequently in all spice types. Of 18 mammalian and avian fecal pellets removed from the spices and analyzed microbiologically, E. coli was found in only 2 pellet specimens. There was no apparent relationship between the enteric microflora found in spices and those found in the fecal pellets.


2018 ◽  
Vol 81 (4) ◽  
pp. 614-618 ◽  
Author(s):  
MARLA G. LEAL-CERVANTES ◽  
SOFÍA M. ARVIZU-MEDRANO ◽  
RAMÓN MARTÍNEZ-PENICHE ◽  
NANCI E. MARTÍNEZ-GONZÁLES ◽  
MONTSERRAT HERNÁNDEZ-ITURRIAGA

ABSTRACT Multiple outbreaks related to Salmonella in tomatoes require an evaluation of the risk associated with cherry tomatoes due to the increase in its production, consumption, and marketing in Mexico's central region. The purpose of this study was to determine the microbial quality of cherry tomatoes obtained from two retail sale points (supermarkets and local markets). Cherry tomato samples (333) were collected from four supermarkets and from four local markets, and the contents of aerobic plate count, molds and yeasts, total coliforms, and Escherichia coli were quantified; the presence of Salmonella was simultaneously determined. The median values of the microbial populations were obtained, and the data were analyzed per the sampling site by using the Wilcoxon and Kruskal-Wallis tests. The median of aerobic plate count content in tomatoes obtained from supermarkets ranged between 2.2 and 4.4 log CFU/g, and in markets from 2.9 to 4.8 log CFU/g. For molds and yeasts, the tomatoes from supermarkets (2.0 to 4.1 log CFU/g) and markets (1.5 to 4.5 log CFU/g) showed similar contents. Regardless of the sampling site, the values of total coliforms were very low, ranging from 1.0 to 1.8 log CFU/g. E. coli was detected in 5.4 and 20.1% of samples from supermarkets and markets, respectively; in both sites, the content was low (0.3 to 5.8 most probable number per g). The incidence of Salmonella was 14.1% in supermarkets and 7.8% in local markets. The results obtained from this investigation highlight the elevated risk for consumer health associated with the ingestion of cherry tomatoes.


1981 ◽  
Vol 44 (2) ◽  
pp. 139-143 ◽  
Author(s):  
G. A. MCKINLEY ◽  
J. S. AVENS

The microbial quality of ground and comminuted turkey meat was examined using raw meat and meat after two cooking times. Eight triplicate samples were obtained from a commercial processing plant over an 8-month period and analyzed for aerobic plate count (APC), coliforms, Escherichia coli, Staphylococcus aureus, Clostridium perfringens and Salmonella. The APC for 29%of the raw ground and 0% of the raw comminuted turkey meat samples was greater than 5.0 × 106/g. Raw ground and comminuted meat yielded a mean coliform most probable number (MPN) of 2.2 × 102 and 6.2 × 102/g respectively. Mean E. coli MPNs per gram were 12 for raw ground and 49 for raw comminuted meat. Twenty-five percent of the 24 raw ground samples, and 46% of the comminuted samples exceeded 50 E. coli MPN/g. S aureus was isolated from 25% of the raw ground and 54% of raw comminuted samples. Salmonellae were isolated from 8% of the raw ground samples and 12% of raw comminuted samples. C. perfringens was isolated from 50 and 55% of 40 ground and 40 comminuted meat samples, respectively. Cooking reduced the microbial numbers and isolation frequency from all samples.


2018 ◽  
Vol 48 (4) ◽  
Author(s):  
Maxsueli Aparecida Moura Machado ◽  
Barbara Müller ◽  
Ricardo César Tavares Carvalho ◽  
Eduardo Eustáquio de Souza Figueiredo

ABSTRACT: Brazil is the largest exporter of beef of the world and Mato Grosso State is the highest beef producer in this country. To maintain product competitiveness and market expansion, sanitary hygienic control of the entire process is indispensable to ensure the attainment of harmless beef and quality. The objective of this study was to evaluate the hygienic sanitary conditions of vacuum-packed beef produced by establishments qualified for export in the state of Mato Grosso, Brazil. A total of 60 samples were submitted to coliforms counts at 35°C and at 45°C and E. coli. The mean contamination by at 35°C and coliforms at 45°C were 3,1 x 102MPN/g and 7.7MPN/g respectively. The presence of E. coli was verified in five samples, representing an occurrence of 8.3% (5/60), and Salmonella spp. in 5% (03/60) of the analyzed samples. The MPN (Most Probable Number) average of coliforms at 35°C and 45°C are in accordance to national and international legislation; however, the presence of Samonella spp., E. coli in some sample indicates a low risk of occurrence of salmonellosis and colibacillosis transmitted by the evaluated beef. However, transmission risk of these diseases cannot be ruled out, since the presence of E. coli does not depend on the amount of coliforms and national legal standards established for the group of thermotolerant coliforms.


1978 ◽  
Vol 41 (8) ◽  
pp. 647-653 ◽  
Author(s):  
JAMES F. FOSTER ◽  
RICHARD C. HUNDERFUND ◽  
JAMES L. FOWLER ◽  
JOHN T. FRUIN ◽  
LINDA S. GUTHERTZ

A survey of the microbial populations of 31 samples of ground beef (GB), textured soy protein (TSP), and ground beef extended with TSP (SGB) after 3 and 10 days of storage at 4 C was done. Analyses included aerobic plate count (APC), psychrotrophic plate count (PPC), coliform Most Probable Number (CMPN) and plate determinations (CPC), Escherichia coli MPN (EMPN) and plate determinations (EPC), Staphylococcus aureus MPN, and fecal streptococcus plate count. Statistical analyses of data from the enumeration procedures showed significant increases in the total microbial flora after 10 days of storage. PPCs were significantly higher than APCs. CMPNs were significantly higher than CPCs for GB and SGB. The EMPNs were significantly higher than EPCs in SGB only. These products contained a variety of microorganisms many in large numbers; however if properly handled and cooked before consumption, these products should present no public health problems.


1977 ◽  
Vol 40 (5) ◽  
pp. 300-303 ◽  
Author(s):  
JAMES F. FOSTER ◽  
JAMES L. FOWLER ◽  
JOHN DACEY

The microbiological quality of four frozen and seven fresh seafood products (597 units in total) obtained from a local retail store were analyzed. Aerobic plate count means (geometric) ranged from 3.5 × 103/g to 9.3 × 104/g for the frozen products and from 7.8 × 104/g to 2.7 × 108/g for fresh products. Average (geometric) coliform Most Probable Number (MPN) values ranged from 1.0 to 7. 7/g for the frozen items and from 7.8/g to 4.8 × 103/g for the fresh seafoods. Employing the MPN method, 4.7% of the 597 units analyzed were positive for Escherichia coli. while 7.9% were positive for Staphylococcus aureus. Two percent of the samples contained Clostridium perfringens. Neither salmonellae nor Vibrio parahaemolyticus was isolated in any of the 597 units.


2006 ◽  
Vol 69 (10) ◽  
pp. 2500-2503 ◽  
Author(s):  
P. PAULSEN ◽  
E. SCHOPF ◽  
F. J. M. SMULDERS

An automated most-probable-number (MPN) system for the enumeration of total bacterial flora and Escherichia coli was compared with plate count agar and tryptone-bile-glucuronide (TBX) and ColiID (in-house method) agar methodology. The MPN partitioning of sample aliquots was done automatically on a disposable card containing 48 wells of 3 different volumes, i.e., 16 replicates per volume. Bacterial growth was detected by the formation of fluorescent 4-methylumbilliferone. After incubation, the number of fluorescent wells was read with a separate device, and the MPN was calculated automatically. A total of 180 naturally contaminated samples were tested (pig and cattle carcass surfaces, n = 63; frozen minced meat, n = 62; and refrigerated minced meat, n = 55). Plate count agar results and MPN were highly correlated (r = 0.99), with log MPN =−0.25 + 1.05·log CFU (plate count agar) (n = 163; range, 2.2 to 7.5 log CFU/g or cm2). Only a few discrepancies were recorded. In two samples (1.1%), the differences were ≥1.0 log; in three samples (1.7%), the differences were ≥0.5 log. For E. coli, regression analysis was done for all three methods for 80 minced meat samples, which were above the limit of detection (1.0 log CFU/g): log MPN = 0.18 + 0.98·log CFU (TBX), r = 0.96, and log MPN =−0.02 + 0.99·log CFU (ColiID), r = 0.99 (range, 1.0 to 4.2 log CFU/g). Four discrepant results were recorded, with differences of >0.5 but <1.0 log unit. These results suggest that the automated MPN method described is a suitable and labor-saving alternative to colony count techniques for total bacterial flora and E. coli determination in minced meat or on carcass surfaces.


1982 ◽  
Vol 65 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Wallace H Andrews ◽  
Philip B Mislivec ◽  
Clyde R Wilson ◽  
Verneal R Bruce ◽  
Paul L Poelma ◽  
...  

Abstract The behavior of microorganisms was studied in mung beans and alfalfa seeds before and after germination in modified, commercially available bean-sprouting kits. The microorganisms were enumerated by the aerobic plate count (APC) and by total yeast and mold count procedures. Salmonella species were artificially inoculated into selected samples and were enumerated by the most probable number (MPN) method. After germination of the beans or seeds into mature sprouts, significant increases were noted in APCs and in MPN values of Salmonella species. Although counts of yeasts and molds did not increase significantly after germination, these samples showed an increase in toxic Aspergillus flavus and potentially toxic Alternaria species. The presence of toxic Penicillium cyclopium molds also increased substantially in 5 samples of a single brand of mung beans. Analysis of selected sprout samples, however, showed no presence of aflatoxin.


1977 ◽  
Vol 79 (3) ◽  
pp. 373-380 ◽  
Author(s):  
A. S. J. Yap

SUMMARYSamples of frozen precooked rock lobster meat from five South Australian fish-processing plants situated in the West Coast and south-east regions were tested over a period of six months during the 1974/5 lobster fishing season. The most probable number (MPN) ofE. coliand coliforms,Staphylococcus aureusandSalmonella, as well as total plate count (TPC) were determined in 480 samples. Monthly geometric mean TPC ranged from 1600/g to 25,000/g. The highest geometric mean of the MPN of coliforms andE. coliwere 4·9/g and 1·8/g respectively. The highest geometric mean number of staphylococci was 18·6/g.Salmonellawas not detected in the 480 units tested. Only 0·4% of the samples had TPC exceeding 100,000/g. Coliforms andE. coliwere not present in 76·1% and 92·7% respectively of the samples tested.Staphylococcus aureuswas not detected in 67·7% of the samples. The numbers of organisms in 82% of the samples fall within the microbiological standards proposed by the National Health and Medical Research Council of Australia for frozen precooked foods. The results of this study demonstrate the microbial quality of precooked lobster meat attainable when good manufacturing practices are used.


2015 ◽  
Vol 21 ◽  
pp. 1-6
Author(s):  
Javid Ali ◽  
Said Hassan ◽  
Dr Ziaurahman ◽  
Inayat Ur Rahman ◽  
Sadhair Abbas ◽  
...  

The present study was aimed to isolate and identify micro-organisms load of drinking water of Mardan city, Khyber Pakhtunkhwa Pakistan. A total of 27 samples of drinking water were collected from different locations of the study area. Total Plate Count was determined by pour plate method, while total coliforms, total fecal coliforms and E. coli were determined by multiple tube fermentation method. Of the total collected samples, 17 (62.96%) samples were contaminated with either one or more than one type of microorganisms. The results of most probable number test showed that 13 (48.15%) samples were unsatisfactory. It was concluded that the water should be treated before consumption for drinking purpose. Regular assessment of the water quality is recommended as regular monitoring of the water quality for improvement not only prevents disease and hazards but also checks the water resources from becoming further polluted. ECOPRINT 21: 1-6, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11897


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