Comparison of the Petrifilm™ Yeast and Mold Culture Film Method to Conventional Methods for Enumerating Yeasts and Molds in Foods

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Group ◽  
Black Pepper ◽  
Plate Count ◽  
Food Groups ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Yeasts And Molds ◽  
Potential Food ◽  
Film Method

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.

Evaluation of a Culture Film (Petrifilm™ YM) Method for Enumerating Yeasts and Molds in Selected Dairy and High-Acid Foods

1990 ◽  
Vol 53 (10) ◽  
pp. 869-874 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R. E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Products ◽  
Cottage Cheese ◽  
Plate Count ◽  
Fungal Cell ◽  
High Acid ◽  
Plate Count Agar ◽  
Sour Cream ◽  
Yeasts And Molds ◽  
Total Yeast

The Petrifilm™ Yeast and Mold (YM) plate was compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) using pour- and surface-plating techniques for its ability to recover yeasts and molds from hard and soft cheeses, cottage cheese, yogurt, sour cream, fruit juice, salad dressing, relishes, and tomato-based sauces. Correlation coefficients of Petrifilm™ YM plates versus pour-APDA, surface-APDA, pour-CPCA, and surface-CPCA for recovering total yeasts and molds from a composite of the eight test foods were, respectively, 0.993, 0.993, 0.994, and 0.995. Slope and intercept values for populations detected using Petrifilm™ YM plates versus traditional systems ranged, respectively, from 0.984 to 1.008 and −0.051 to 0.149. The coefficient of variation for total yeast and mold populations recovered on Petrifilm™ YM plates was 1.0% compared to 1.2 to 1.7% for traditional enumeration systems. Regardless of the enumeration system employed or the type of fungal cell, i.e., yeast or mold, being enumerated, significantly (P ≤ 0.05) higher populations were generally detected after 5 d compared to 3 d of incubation. After 5 d of incubation, in no case were yeast or total yeast and mold populations detected in the eight food products using Petrifilm™ YM plates significantly lower than respective populations detected using traditional pour- and surface-plating techniques and media. When Petrifilm™ YM plates were used, significantly higher total yeast and mold populations were detected in 3, 1, and 1 out of eight food products compared to using, respectively, pour-APDA, surface-APDA, and surface-CPCA enumeration systems. The Petrifilm™ YM plate offers an acceptable alternative to traditional methods for enumerating yeasts and molds in the dairy and high-acid products evaluated in this study.

Effect of Stored Pre-Poured Plates on Microbial Enumeration Using the Surface Plate Method1

1980 ◽  
Vol 43 (8) ◽  
pp. 592-594 ◽  
Author(s):  
J. E. KENNEDY ◽  
P. E. PHILLIPS ◽  
J. L. OBLINGER
Keyword(s):  
Correlation Coefficients ◽  
Storage Period ◽  
Regression Coefficients ◽  
Plate Count ◽  
Plate Method ◽  
Plate Count Agar ◽  
Plastic Bags ◽  
Plate Counts ◽  
Microbial Enumeration ◽  
Surface Plate

The surface plate method, using freshly pre-poured agar plates and/or stored pre-poured plates and the pour plate method were compared for enumeration of microorganisms in fresh bologna, fresh ground beef, frozen turkey pot pie and bacterial suspensions of Pseudomonas fluorescens and Streptococcus faecalis. Stored pre-poured Plate Count Agar (PCA) plates were packaged in plastic bags and held at 5 C for up to 6 weeks before use. Aerobic plate counts were derived from plates incubated at 35 C for 48 h, 20 C for 5 days and 7 C for 10 days. Differences in counts between methods for a given sample, incubation and pre-poured plate storage period were less than 0.5 log cycle in 97% of the comparisons. Regression and correlation coefficients between methods were highly significant; correlation coefficients varied from 0.987 to 0.999, and regression coefficients from 0.977 to 1.068 between any pair of methods. Storage of pre-poured plates for up to 6 weeks appeared to have no significant effect on recovery of microorganisms, using the surface plate technique.

Enumeration of Enterococci and Aerobic Mesophilic Plate Count in Dried Soup Using Three Reconstitution Methods

1985 ◽  
Vol 48 (9) ◽  
pp. 770-771 ◽  
Author(s):  
WEI-TSYI TING ◽  
GEORGE J. BANWART
Keyword(s):  
Plate Count ◽  
Plate Count Agar ◽  
Plate Counts

A naturally contaminated dried soup sample was reconstituted by three different methods (1:1 swirl, 1:9 soak and 1:9 rapid rehydration) and analyzed for enterococci on m-enterococcus agar and aerobic mesophilic plate count on plate count agar. The enterococcal counts obtained by the 1:1 swirl and the 1:9 soak methods were 41.6% and 26.5%, respectively, higher than that of the commonly used 1:9 rapid rehydration method. The aerobic mesophilic plate counts for the three systems were not significantly different.

Effect of Delayed Heading on Some Quality Attributes of Penaeus Shrimp1

1979 ◽  
Vol 42 (5) ◽  
pp. 407-409 ◽  
Author(s):  
R. J. ALVAREZ ◽  
J. A. KOBURGER
Keyword(s):  
Panel Data ◽  
Storage Period ◽  
Plate Count ◽  
Sensory Panel ◽  
Bacterial Populations ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Pseudomonas Species ◽  
Standard Plate ◽  
Plate Counts

To determine the effect of delayed heading on shrimp quality, shrimp were stored on ice with and without heads for 10 days. Some shrimp were delay-headed after 5 days and returned to ice for the remainder of the storage period. Microbiological studies were conducted at 0, 5 and 10 days of storage. Total aerobic plate counts were done using Standard Plate Count agar with an added 0.5% NaCl. Incubation was at 20 C for 5 days. Analyses indicated similar counts on shrimp tails stored with or without heads and those delayed-headed. Counts ranged from 2.4 × 106 bacteria/gram at 0 day to 1.6 × 109 bacteria/gram on the 10th day. Identification of the flora present revealed that the same major groups of organisms predominated on shrimp tails subjected to the different storage treatments and the head did not alter development of the usual flora. Flavobacterium, Pseudomonas, Planococcus, Moraxella and the Vibrio/Aeromonas group were the major genera encountered. A shift in bacterial populations was observed during storage. Flavobacterium species predominated during the first 5 days of storage; however, after the fifth day Pseudomonas species predominated. Sensory panel data revealed no differences in acceptability between shrimp tails stored with or without heads and those delay-headed.

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.

Effect of Pyruvate on Recovery of Fungi from Foods

1986 ◽  
Vol 49 (3) ◽  
pp. 231-232 ◽  
Author(s):  
JOHN A. KOBURGER
Keyword(s):  
Food Samples ◽  
Plate Count ◽  
Sodium Pyruvate ◽  
Plate Count Agar ◽  
Yeasts And Molds

The addition of 0.5% sodium pyruvate to antibiotic-supplemented plate count agar significantly increased the recovery of fungi from 50 food samples. Both yeasts and molds responded to the addition of pyruvate, with an overall increase in recovery of 8.0%.

Fungi in Foods

1975 ◽  
Vol 38 (8) ◽  
pp. 466-468 ◽  
Author(s):  
J. A. KOBURGER ◽  
B. Y. FARHAT
Keyword(s):  
Plate Count ◽  
Plate Count Agar ◽  
Significant Difference ◽  
Yeasts And Molds

Five media, with added antibiotics, were compared for their ability to recover yeasts and molds from 31 foods. Overall, no significant difference in recovery was found among Mycophil, Plate Count, Malt, or Potato dextrose agars but all were superior to Sugar Free agar. On the basis of recovery of organisms, availability, ease of management, and cost, Plate Count agar with antibiotics is recommended for routine enumeration of yeasts and molds in foods.

scholarly journals Validation and reproducibility of an FFQ for use among adults in Botswana

2012 ◽  
Vol 16 (11) ◽  
pp. 1995-2004 ◽  
Author(s):  
Maria D Jackson ◽  
Boitumelo S Motswagole ◽  
Lemogang D Kwape ◽  
Rosemary I Kobue-Lekalake ◽  
Tidimalo B Rakgantswana ◽  
...  
Keyword(s):  
Vitamin E ◽  
Correlation Coefficients ◽  
Food Group ◽  
Leafy Vegetables ◽  
Spearman Correlation ◽  
Food Groups ◽  
Nutrient Intakes ◽  
Relative Validity ◽  
Dark Green ◽  
Β Carotene

AbstractObjectiveTo evaluate the validity and reproducibility of a 122-item interviewer-administered quantitative FFQ developed to determine food and nutrient intakes of adults in Botswana.DesignRelative validity of the FFQ was evaluated by comparing nutrient and food group intakes against four non-consecutive 24 h recalls administered over 12 months. The FFQ was repeated after 1 year to assess reproducibility.SettingKanye, Botswana.SubjectsSeventy-nine adults aged 18–75 years.ResultsSpearman correlation coefficients for the validity of energy-adjusted nutrients ranged from 0·42 (carbohydrate) to 0·49 (protein) for macronutrients and from 0·23 (Fe) to 0·44 (PUFA) for micronutrients. Exact agreement of quartile distribution for nutrients between the FFQ and recalls ranged from 27 % to 72 %. Weighted kappa values were lowest for retinol (0·13), Fe (0·22) and β-carotene (0·25) and ranged from 0·33 (SFA) to 0·59 (folate) for other nutrients (energy, carbohydrate, protein, fat, Ca and vitamin E). Spearman correlation coefficients between the recalls and FFQ for food groups ranged from 0·18 (dark green leafy and yellow vegetables) to 0·58 (poultry). Reproducibility correlation coefficients (energy-adjusted) varied between 0·39 for retinol and 0·66 for vitamin E, with most values falling between 0·50 and 0·60.ConclusionsThe FFQ had good relative validity for estimating habitual food group and nutrient intakes, but was poor for some micronutrients (Fe, retinol and β-carotene) and foods (fruits and dark green leafy vegetables).

scholarly journals Validity and reproducibility of the food-frequency questionnaire used in the Shanghai Men's Health Study

2007 ◽  
Vol 97 (5) ◽  
pp. 993-1000 ◽  
Author(s):  
Raquel Villegas ◽  
Gong Yang ◽  
DaKe Liu ◽  
Yong-Bing Xiang ◽  
Hui Cai ◽  
...  
Keyword(s):  
Food Frequency Questionnaire ◽  
Correlation Coefficients ◽  
Food Group ◽  
Men’S Health ◽  
Health Study ◽  
Men's Health ◽  
Food Groups ◽  
Food Frequency ◽  
Exact Agreement ◽  
Usual Intake

We evaluated the validity and reproducibility of the FFQ used in the Shanghai Men's Health Study (SMHS). The study included 195 randomly selected participants of the SMHS who completed one FFQ at baseline, twelve 24-hour dietary recalls (24-HDR) (once a month for twelve consecutive months) and a second FFQ at the end of the study. The FFQ accounted for 88·78 % of the foods recorded in the 24-HDR surveys. The validity of the FFQ was evaluated by comparing nutrient and food group intake levels from the second FFQ and the multiple 24-HDR. Correlation coefficients ranged from 0·38 to 0·64 for macronutrients, 0·33 to 0·58 for micronutrients and 0·35 to 0·72 for food groups. Misclassification to opposite quartiles for nutrients and food groups was rare, ranging from 1·5 to 7·7 %, while exact agreement rates were between 31·8 and 53·3 %. The reliability of the FFQ was assessed by comparing the intake levels from the two FFQ. Correlation coefficients were 0·39 to 0·53 for macronutrients, 0·38 to 0·52 for micronutrients and 0·39 to 0·64 for food groups. Exact agreement rates for quartile distribution were between 31·8 and 49·2 %, while misclassification to opposite quartiles was between 1·5 and 6·2 %. These data indicate that the SMHS FFQ can reasonably categorise usual intake of nutrients and food groups among men living in urban Shanghai.

Fungi in Foods

1975 ◽  
Vol 38 (12) ◽  
pp. 745-746 ◽  
Author(s):  
J. A. KOBURGER ◽  
A. R. NORDEN
Keyword(s):  
Food Samples ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Plate Count Agar ◽  
Yeasts And Molds ◽  
Surface Plate

It was possible to compare recovery of yeasts and molds from 30 food samples by three methods, employing plate count agar and broth with added antibiotics. Although the pour plate and surface plate methods gave comparable results, the Most Probable Number (MPN) procedure consistently yielded the highest counts. With some of the samples, the MPN method was the only one in which recovery occurred. It thus appears that this procedure is practical for detection of fungi and may be of use in survey work or when analyzing foods containing low numbers of microorganisms.

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