Analyst Variation in Doing the Standard Plate Count as Described in Standard Methods for the Examination of Dairy Products
- 1 January 1978
- journal article
- research article
- Published by Elsevier in Journal of Food Protection
- Vol. 41 (1) , 4-7
- https://doi.org/10.4315/0362-028x-41.1.4
Abstract
Five analysts participated in a study to evaluate the following aspects of the 13th edition of Standard Methods for the Examination of Dairy Products (SMEDP): (a) analyst variation in overall Standard Plate Counts (SPC), and (b) analyst duplication of bacterial colony counts on agar places. Each analyst prepared 24 samples of pasteurized, homogenized milk during a successive 8-day period (i.e., 3 samples/day), and then the analysts estimated the numbers of bacterial colonies for these, as well as other analysts' plates, initially after 48 h of incubation, and then 1 h later and 24 h later. Statistically significant differences in colony enumerations were found between analysts in preparation of agar plates on 3 days. Significant differences were also noted between analysts for bacterial counts of agar plates. Mean bacterial estimates of certain analysts ranged between 565 and 948, and fluctuated greatly between the initial, 1-h, and 24-h determinations. These results indicate that the “standards of accura...This publication has 1 reference indexed in Scilit:
- Accuracy and Speed in Counting Agar PlatesJournal of Food Protection, 1977