Page 46 - FoodFocusThailand No.232 July 2025

STRONG QC & QA

(a) (b)

ภาพที่่� 2 (a) 3M Petrifilm E. coli / coliform count plate (EC) และ
TM
แผ่่น spreader (b) ลักษณะโคโลนีของ E. coli และโคลิฟอร์์ม
Figure 2 (a) 3M Petrifilm™ E. coli / Coliform Count Plate (EC) and
spreader plate (b) Appearance of E. coli and coliform
colonies.

ที่่�มา / Source: http://products3.3m.com/catalog/br/pt002/food_
beverage/-/node_WJRHXZ79GDbe/root_GSHL20G7FLgv/vroot_
DDPS3WWBL3ge/gvel_TD143R1RTWgl/theme_br_foodbeverage_3_0/
command_AbcPageHandler/output_html และ https://www.coursehero.
com/file/12954222/3M-Coliform/
5. Advanced Technologies have been developed
medium used to count coliforms and E. coli. It contains Violet to enhance the accuracy and precision of microbial
Red Bile (VRB) medium, water-soluble gel, and dyes analysis, making them suitable for precise identification of
(Triphenyltetrazolium Chloride and 5-Bromo-4-chloro-3-indolyl- microbial species and strains. One example is Multilocus
β-D-glucuronide) to aid colony counting. The dye 5-Bromo-4- Sequence Typing (MLST), which classifies microorganisms
chloro-3-indolyl-β-D-glucuronide is specifically used for by analyzing the base sequences of multiple gene loci,
detecting E. coli, as it is broken down by the enzyme typically based on housekeeping genes that are consistently
Glucuronidase, which is present in E. coli, resulting in blue expressed. Another key technology is Whole Genome
colonies with gas bubbles. In contrast, coliforms appear as red Sequencing (WGS), which deciphers the entire nucleotide
colonies (see Figure 2b), due to the reduction of sequence of a genome. This method allows for the
Triphenyltetrazolium Chloride combined with gas production detection of single-base differences, enabling highly
from lactose fermentation. accurate strain-level identification of microorganisms. The
4. Rapid Microbial Test Kit - Rapid test kits for detecting resulting data can be efficiently compared with international
bacteria and mold are widely used as basic tools in databases. Although these technologies provide the
microbiological analysis. Popular options include Petrifilm and highest level of precision in pathogen identification, they
other ready-to-use test kits, which offer advantages such as involve high costs and require specialized technical expertise
ease of use, convenience, and quick results. However, their to perform.
ability to specifically identify pathogenic microorganisms may The chart (P.46) compares the strengths and
be limited compared with other methods. weaknesses of various microbiological testing methods for
food, considering key factors such as accuracy of
results, speed of analysis, technical complexity, operational
costs, ability to identify pathogens, and precision in
quantification. Researchers and industry operators can use
this information to select the most appropriate testing method
based on the specific objectives of the analysis and
compliance with relevant legal requirements. When
combined with the available budget, this helps planning
a testing process that is efficient, accurate, and cost-effective
in terms of both expenses and time. Ultimately, this
contributes to reducing costs and improving overall
business performance.
ภาพที่่� 3 ชุุดทดสอบแบคทีเร์ีย Salmonella spp. (API 20E Identification)
(bioMérieux, France) identification โดย Isolate 1 เป็็น
Salmonella enteriga และ Isolate 2 เป็็น Raoultella
ornithinolytica More Information Service Info C007
Figure 3 Salmonella spp. bacterial test kit (API 20E Identification)
(bioMérieux, France). Isolate 1 is identified as Salmonella
enterica and Isolate 2 as Raoultella ornithinolytica.

46 FOOD FOCUS THAILAND JUL 2025

24/6/2568 BE 16:54
42-46_Strong QC&QA_�������.indd 46
42-46_Strong QC&QA_�������.indd 46 24/6/2568 BE 16:54