Evaluation of the Spiral Plate Maker for the Enumeration of Micro‐organisms in Foods

Abstract

A statistically based comparison of five methods of enumerating bacteria in foods has been undertaken to assess the potential application of the Spiral Plate Maker (Gilchrist et al. 1973) which is claimed to reduce very significantly the costs involved in the quantitative estimation of viable micro-organisms in foods. The performance of the Spiral Plate Maker was compared with that of three conventional methods (pour plate, surface spread plate and drop count) for the examination of four types of food by four different operators. Analysis of variance showed that there were no differences between the methods at the 5% level although some isolated interactions occurred. Regression and correlation coefficients between the various methods were all highly significant and the results obtained by the spiral plate method were within the limits of error for traditional quantitative methods. The spiral plate method, in many cases, can replace advantageously any of the other methods for the quantitative estimation of viable microorganisms in foods. Labour requirements for the enumeration of micro-organisms by the spiral plate method were only 31% of that required for one conventional method. In addition considerable savings in materials were achieved.(1491

Preparation and characterisation of food grade chitosan from housefly larvae

“…Arsenic (As) was measured by hydride generation atomic fluorescence spectrometry according to the method of El-Hadri et al (2007). Aerobic bacterial count was determined using the method described by Jarvis et al (1977) and coliforms were enumerated by the method of Feldsine et al (1994). Pathogens, including Staphylococcus aureus and Salmonella, were screened by the methods of Bennett et al (1986) and June et al (1995) …”

Enumeration of micro-organisms in food: a comparative study of five methods

“…However, a most useful development in recent years has been the Spiral Plate Maker (Gilchrist et al 1973) and the spiral plate count method is now accepted in the U.S.A. by the Association of Official Analytical Chemists (1977) as an official procedure for the examination of foods and cosmetics. Reports on the spiral plate method, and comparisons with conventional methods have shown that the procedure has many advantages which recommend its use in a routine laboratory Gilchrist et al 1976;Peeler et al 1977;Jarvis, Lach & Wood, 1977). Results from this laboratory (J. M. Kramer & M. Kendall, unpublished data) endorse these findings.…”

The microbiology of selected retail food products with an evaluation of viable counting methods

“…Previous comparison between methods of enumeration of micro-organisms have been carried out under strictly controlled conditions on pure cultures of bacteria, spore suspensions, or relatively small numbers of food samples (Jarvis, Lach & Wood, 1977;Hedges, Shannon & Hobbs, 1978;Kramer & Gilbert, 1978, Kramer, Kendall & Gilbert, 1979. These workers showed a good correlation between the methods tested.…”