Microbiological Screening Method for Indication of Irradiation of Spices and Herbs: A BCR Collaborative Study

1993 ◽  
Vol 76 (3) ◽  
pp. 674-681 ◽  
Author(s):  
Gun Wirtanen ◽  
Anna-Maija Sjöberg ◽  
Flemming Boisen ◽  
Timo Alanko ◽  
◽  
...  
Keyword(s):  
Collaborative Study ◽  
Screening Method ◽  
Conclusive Evidence ◽  
Plate Count ◽  
Heat Treated ◽  
Relative Standard ◽  
Plate Count Method ◽  
The Difference ◽  
Aerobic Plate Count ◽  
Direct Epifluorescent Filter Technique

Abstract A BCR1 collaborative study was conducted with a microbiological screening method based on the combined use of the direct epifluorescent filter technique (DEFT) and the conventional aerobic plate count method (APC) for detection of irradiation of spices and herbs. Collaborative samples of whole allspice, whole and powdered black peppers, whole white pepper, paprika powder, cut basil, cut marjoram, and crushed cardamom irradiated with doses of 0, 5, and 10 kGy were analyzed by 8 laboratories. The total number of the collaborative samples, with arbitrarily labeled codes, was 192. The percentage of acceptable results was 95.5%. The identification of irradiated from nonirradiated spices and herbs was analyzed statistically by using explorative techniques. The average values of the differences between DEFr and APC in samples irradiated with doses of 5 and 10 kGy were 5.1 and 6.1 logarithmic units, respectively. The differences between DEFT and APC generally increased to at least 3.5 logarithmic units, whereas the difference in the case of unirradiiated spices was insignificant. However, conclusive evidence of irradiation relies on the knowledge that the sample was not fumigated or heat treated. The reproducibility relative standard deviations for the differences were 12.3,19.9, and 20.7% with the closes of 10 and 5 kGy and for unirradiated samples, respectively, indicating acceptable variabilities among laboratories. Received

Dry Rehydratable Film for Enumeration of Total Aerobic Bacteria in Foods: Collaborative Study

1990 ◽  
Vol 73 (2) ◽  
pp. 242-248
Author(s):  
Michael S Curiale ◽  
Therese Sons ◽  
J Sue Mcallister ◽  
Barbara Halsey ◽  
Terrance L Fox
Keyword(s):  
Collaborative Study ◽  
Agar Plate ◽  
Plate Count ◽  
Relative Standard ◽  
Plate Counts ◽  
Agar Method ◽  
Standard Deviations ◽  
Aerobic Plate Count ◽  
Film Method ◽  
Dry Film

Abstract A rehydratable dry-film plating procedure for aerobic plate counts has been compared to the standard agar plate method (966.23B and C, 15th ed.; 46.014-46.015, 14th ed.) in a collaborative study by 12 laboratories. Each laboratory analyzed the normal microflora of 3 samples in duplicate for 6 products. The aerobic plate counts ranged from 1.0 X 103 to 1.0 X 108 cfu/g. The products were flour, nuts, frozen raw shrimp, spice, frozen raw ground turkey, and frozen and refrigerated vegetables. Repeatability standard deviations of the 2 methods did not differ significantly for 13 of 18 test samples. For 1 shrimp and 2 turkey samples, the dry-film method had lower repeatability variances (P < 0.05) and for 1 spice sample the agar method had lower repeatability variances (P < 0.05). Relative standard deviations of repeatability were between 1.7 and 15.5% for the dry-film method and 1.2 and 16.0% for the agar method. Relative standard deviations of reproducibility ranged from 2.4 to 23.4 % for the dry-film method and 2.3 to 18.8% for the agar method. The dry rehydratable film method has been adopted official first action for determination of the aerobic plate count.

Evaluation of the MC-Media Pad® Rapid Aerobic Count Device for the Enumeration of Total Aerobic Counts in a Variety of Foods: Collaborative Study, First Action Official MethodSM 2019.02

2020 ◽  
Vol 103 (5) ◽  
pp. 1318-1325
Author(s):  
Benjamin Bastin ◽  
Nicole Klass ◽  
Erin Crowley ◽  
James Agin ◽  
Charlotte Lindhardt ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Collaborative Study ◽  
Food Products ◽  
Plate Count ◽  
Contamination Level ◽  
Microbial Count ◽  
Reference Methods ◽  
The Difference ◽  
Aerobic Plate Count ◽  
Inspection Service

Abstract Background The MC-Media Pad® Rapid Aerobic Count (RAC) is a ready-to-use culture device combining a test pad coated with medium and water absorption polymers that are designed for the rapid quantification of total aerobic bacteria in food products. Objective The MC-Media Pad RAC was compared to the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook, Chapter 3.02: Quantitative Analysis of Bacteria in Foods as Sanitary Indicators for raw ground pork and the Standard Methods for the Examination of Dairy Products, Chapter 6: Microbial Count Methods for yogurt drink. Method The candidate method was evaluated against the reference methods using a paired study design in a multi-collaborator study, following the current AOAC INTERNATIONAL Official Methods of AnalysisSM Appendix J guidelines. Three target contamination levels (low, medium, and high) were evaluated. MC-Media Pad RAC devices were enumerated after 24 and 48 h of incubation. Results Plate counts obtained by both methods were log10-transformed and the difference of means (including 95% confidence intervals), repeatability SD, and reproducibility SD were determined for each contamination level. All 95% confidence intervals for mean difference fell easily within ±0.10, the performance requirement being ±0.5. Conclusion The MC-Media Pad RAC (for both 24 and 48 h) and both reference methods for each contamination level were therefore shown to be equivalent, with 97.5% confidence. Highlights The new method offers a convenient alternative to the reference methods for detection of aerobic plate count in food products, yielding reliable and comparable results in 24 or 48 h compared to 48 h for the reference methods.

Collaborative Study Comparing the Spiral Plate and Aerobic Plate Count Methods

1977 ◽  
Vol 60 (4) ◽  
pp. 807-812 ◽  
Author(s):  
James E Gilchrist ◽  
Cecil B Donnelly ◽  
James T Peeler ◽  
Jeptha E Campbell
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Plate Count ◽  
Plate Method ◽  
Components Of Variance ◽  
Plating Technique ◽  
Acceptable Alternative ◽  
Plate Count Method ◽  
Aerobic Plate Count ◽  
Spiral Plate

Abstract The spiral plate count method is a semiautomated plating technique that greatly reduces manpower and material costs normally associated with the pour plating technique. In this collaborative study, 8 laboratories compared the spiral and pour plating techniques, using 4 samples each of 3 products : frozen pumpkin pie, frozen chicken pot pie, and shampoo. The results show that 10 of the 12 comparisons of means of the pour and spiral methods were not significantly different; 2 values were significant at α = 0.01. Overall, the components of variance were less than that of the current milk standard, and the replicate per cent coefficient of variation was satisfactory. This study indicates that the spiral plate method is an acceptable alternative to the pour plate method; the spiral plate method has been adopted as official first action.

Hydrophobic Grid Membrane Filter Method for Aerobic Plate Count in Foods: Collaborative Study

1986 ◽  
Vol 69 (4) ◽  
pp. 671-676 ◽  
Author(s):  
Phyllis Entis ◽  
◽  
J Allen ◽  
A Bhatnagar ◽  
A Brouwer ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Raw Milk ◽  
Plate Count ◽  
Filter Method ◽  
Membrane Filter Method ◽  
Aerobic Plate Count ◽  
Egg Powder ◽  
Raw Poultry ◽  
Whole Egg

Abstract Twenty-one laboratories participated in a collaborative study to validate a hydrophobic grid membrane filter (HGMF) method for aerobic plate count by comparing its performance against the AOAC/APHA pour plate method. Raw milk, raw poultry, whole egg powder, flours, and spices were included in the study. Counts obtained by the HGMF and pour plate methods did not differ significantly, except in the case of whole egg powder, for which the HGMF method produced significantly higher counts. The hydrophobic grid membrane filter method for aerobic plate count in foods has been adopted official first action.

A Model for Statistical Evaluation of Precision Parameters of Microbiological Methods: Application to Dry Rehydratable Film Methods and IDF Reference Methods for Enumeration of Total Aerobic Mesophilic Flora and Coliforms in Raw Milk

1991 ◽  
Vol 74 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Christine Piton ◽  
Rémy Grappin
Keyword(s):  
Statistical Approach ◽  
Collaborative Study ◽  
Raw Milk ◽  
Confirmatory Test ◽  
Plate Count ◽  
Reference Methods ◽  
Microbiological Methods ◽  
Relative Standard ◽  
Standard Deviations ◽  
Total Bacteria

Abstract A new statistical approach for collaborative study data of microbiological methods Is proposed. This Includes a confirmatory test to the Polsson distribution of the number of colonies. In addition, 2 new statistical parameters are used to express precision as a percent of the original unit: the geometric relative standard deviation (GRSD) and the critical relative difference between 2 measurements (RD95). This statistical approach was applied to an Interlaboratory study to assess and compare the precision of both dry rehydratable film (PetrlfUrn® SM and Petrifllm® VRB) methods and International Dairy Federation (IDF) reference methods [total aerobic mesophilic plate count (TAMPC) and violet red bile lactose agar (VRBL) methods] for estimation of total bacteria and collform, respectively, in raw milk. Each of the 14 laboratories In the study analyzed 40 laboratory samples (20 different materials In blind duplicates) for total bacteria and collform counts by both the Petrifllm and standard methods. Repeatability standard deviations (In log10 unit) of TAMPC, Petrifllm SM, VRBL, and Petrifllm VRB were 0.106, 0.089, 0.219, and 0.171, respectively; their reproducibility standard deviations were 0.170,0.167,0.348, and 0.199, respectively.

Study on the Detection of Total Colony in Medical and Health Environment Based on ATP Bioluminescence

2018 ◽  
Vol 24 (2) ◽  
Author(s):  
Zhe Li
Keyword(s):  
Culture Method ◽  
Pass Rate ◽  
Plate Count ◽  
Count Method ◽  
Atp Bioluminescence ◽  
Bioluminescence Assay ◽  
Plate Count Method ◽  
The Difference ◽  
Atp Bioluminescence Assay ◽  
Bioluminescence Method

In this paper, the application of ATP fluorescence in the detection of colonies in the health environment of hospitals was studied. Firstly, the principle of ATP bioluminescence method was described. Then, ATP bioluminescence and plate count method were used to test the density of the surface of the objects in selected area, taking the time points 2 hours after disinfection as the time nodes. The results showed that the difference between the qualified rate of ATP bioluminescence assay and the plate count method was statistically significant {P<0.01}. Therefore, ATP bioluminescence method was highly correlated with bacterial culture method. The correlation coefficient of pass rate of the two methods was 0.782, which indicated that there was a positive correlation between the two test results. Besides, the detection results showed that ATP bioluminescence method had higher sensitivity than plate counting method. Therefore, ATP bioluminescence method was more suitable for the rapid detection of the colony of hospital health environment, and helps the hospital to better manage its environmental hygiene conditions. 

Comparison of a Four-Section Spindle and Stomacher for Efficacy of Detaching Microorganisms from Fresh Vegetables

2015 ◽  
Vol 78 (7) ◽  
pp. 1380-1386 ◽  
Author(s):  
DO-KYUN KIM ◽  
SOO-JI KIM ◽  
DONG-HYUN KANG
Keyword(s):  
Foodborne Pathogens ◽  
Food Samples ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Vegetable Samples ◽  
Fresh Vegetable ◽  
Detection Analysis ◽  
Fresh Vegetables ◽  
The Difference ◽  
Aerobic Plate Count

This study was undertaken to compare the effect of the spindle and stomacher for detaching microorganisms from fresh vegetables. The spindle is an apparatus for detaching microorganisms from food surfaces, which was developed in our laboratory. When processed with the spindle, food samples were barely disrupted, the original shape was maintained, and the diluent was clear, facilitating further detection analysis more easily than with stomacher treatment. The four-section spindle consists of four sample bag containers (A, B, C, and D) to economize time and effort by simultaneously processing four samples. The aerobic plate counts (APC) of 50 fresh vegetable samples were measured following spindle and stomacher treatment. Correlations between the two methods for each section of the spindle and stomacher were very high (R2 = 0.9828 [spindle compartment A; Sp A], 0.9855 [Sp B], 0.9848 [Sp C], and 0.9851 [Sp D]). One-tenth milliliter of foodborne pathogens suspensions was inoculated onto surfaces of food samples, and ratios of spindle-to-stomacher enumerations were close to 1.00 log CFU/g between every section of the spindle and stomacher. One of the greatest features of the spindle is that it can treat large-sized samples that exceed 200 g. Uncut whole apples, green peppers, potatoes, and tomatoes were processed by the spindle and by hand massaging by 2 min. Large-sized samples were also assayed for aerobic plate count and recovery of the three foodborne pathogens, and the difference between each section of the spindle and hand massaging was not significant (P &gt; 0.05). This study demonstrated that the spindle apparatus can be an alternative device for detaching microorganisms from all fresh vegetable samples for microbiological analysis by the food processing industry.

Enzyme-Linked Immunosorbent Assay for Detection of Zearalenone in Corn, Wheat, and Pig Feed: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1500-1508 ◽  
Author(s):  
Glenn A Bennett ◽  
Terry C Nelsen ◽  
Brjnton M Miller
Keyword(s):  
Immunosorbent Assay ◽  
Collaborative Study ◽  
Screening Method ◽  
The United States ◽  
False Positives ◽  
Enzyme Linked Immunosorbent Assay ◽  
Elisa Method ◽  
False Negatives ◽  
Relative Standard ◽  
Pig Feed

Abstract A direct competitive enzyme-linked immunosorbent assay (ELISA) screening method for zearalenone in corn, wheat, and feed at 500 ng/g was evaluated by 23 collaborators (22 laboratories) in an international collaborative study. Eighteen samples of spiked or naturally contaminated corn, wheat, and pig feed were prepared by the sponsoring laboratory and sent for testing with complete test kits to participating collaborators in Canada, Italy, Sweden, The Netherlands, and the United States. Test samples were extracted with methanolwater solution (70 + 30) by shaking on a wrist-action shaker for 3 min. A portion of the extract was mixed with an equal volume of zearalenone-enzyme conjugate, and the mixture was incubated with zearalenone-specific monoclonal antibodies coated onto microtiter wells. All test samples were assayed in duplicate. One of 52 (2%) blanks was reported positive. Thirty-nine of the 52 (75%) samples that were spiked at 500 ng/g were reported as positive. Forty-nine of the 51 (96%) samples with concentrations at or above 1000 ng/g were reported as positive. The overall incidence of false negatives was 6.0% and the incidence of false positives was 22.7% by the ELISA method. Only one (3.4%) false negative was reported for samples containing ≥800 ng/g. In the spectrophotometric method, 8 collaborators determined approximate levels of zearalenone in test samples from standard curves constructed from spiked extracts (0–3000 ng/g of each commodity tested). This method gave and overall incidence of false negatives of 5.7% and false positives of 17.8%. Average relative standard deviations, RSDr (repeatability) and RSDR (reproducibility), were 11.6 and 25.1% for spiked samples and 11.7 and 33.1% for naturally contaminated samples, respectively. Standard curves were constructed with each set of samples assayed. Comparison of absorbance values from these standard curves indicate the performance of reagents and antibody used in the assay. The ELISA method has been adopted first action by AOAC INTERNATIONAL as a screening method for zearalenone at ≥800 ng/g in corn, wheat, and pig feed.

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