The aim of the study was to compare of International Standard Organization (ISO) 7251, ISO 16649‐3 most probable number (MPN) assay for the enumeration of Escherichia coli group to the Tempo EC automated method using a variety of spiked milk and milk product foods. Foods evaluated in this study included wet pasta (crema), milk, ayran, and ice cream. The spiked food samples were diluted at three inoculation levels such as low, medium, and high. A comparison of the results indicated that automated system approximated the inoculation level to an automated system. In this study, TEMPO EC, ISO 16649‐3, and ISO 7251 methods are compliant for MPN E. coli count in high, medium, and low contamination level studies. Nevertheless, for precise results, performing primary validation studies by ISO, Association Française de Normalisation (AFNOR), and/or Association Of Official Analytical Chemists (AOAC) will give more reliable results. Practical applications In Turkish Food Codex Microbiological Criteria Communique, it is requested to perform studies of E. coli analysis method in milk and milk products as per ISO 16649‐3. However, in the revised version of ISO 16649‐3, it is stated in the scope of the standard that this method does not provide a full assessment for all products particularly for milk and milk products and that ISO 7251 method should be used in these samples. As it is required in new methods, it has been intended to perform comparative analyses to low, medium, and high inoculation level with rapid the TEMPO EC card and conventional test methods by ISO, AFNOR, and/or AOAC. If the use of TEMPO EC, laboratory response time will improve with automation reducing the time for enumeration of E. coli from 4 days to 24 hr, especially critical for evaluation of perishable foods and outbreak events.

No abstract

IntroductionStudies on food safety have been carried out for nearly 40 years to improve quality of life (1). Since the bovine spongiform encephalopathy (BSE) and dioxin crises in Europe and the beef-based Escherichia coli O157:H7 infections in North America (2), many have lost confidence in the institutions responsible for securing food safety (3,4). Consequently, the relevant authorities have an obligation to develop adequate food safety strategies. New or revised legal regulations, as well as the amenities to ensure the adequate application of food security measures, are also needed (2).It has become apparent that the hazard analysis critical control point (HACCP) approach was an inadequate effort in securing food safety (5,6). Furthermore, the HACCP is not an efficient system (6). To guarantee food safety and eliminate risks, which are compulsory in the HACCP system, prerequisite programs and new HACCP applications are required to adhere to good agricultural practices (6,7).The International Organization for Standardization (ISO) 22000 standard was introduced by the Codex Alimentarius Commission (CAC) with the aim of fulfilling the HACCP principles. This standard combines prerequirement programs with the HACCP. According to research conducted on pork pâté butchers (7), it is necessary to apply the CAC and HACCP principles that formed the basis of the ISO 22000. Furthermore, the authors of this study acknowledge that many bacterial threats such as Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus could be controlled by the application of good hygiene practices and that 3 bacterial threats, namely Bacillus cereus, Clostridium botulinum, and C. perfringens, could be suppressed by taking specific control measures.Previously, a study was conducted in order to identify the sources of microbial contamination in a sausage processing line. Total mesophilic aerobic (TMA) bacteria numbers were found to be very high before the cooking process, but they decreased significantly after the cooking process (8). Bacillus cereus distribution in processed-meat products (such as ground beef, chicken, Vienna sausages, jambon, and salami) in South Africa was found in one chicken sample, in 3 salami samples, and in 5 Vienna sausages (9). In Iran, 6.66% of 645 raw and cooked meat samples were contaminated with Salmonella spp. (10).

ÖZ TS EN ISO/IEC 17025:2017 standardı ile akreditasyon kapsamındaki laboratuvarlar, sonuçlarının güvenilirliğini ortaya koyabilmek için analiz süresince ölçüm sonucuna yansıma etkisi bulunan tüm değişkenlerin (matriks, donanım, vb) dağılımlarını karakterize ederek, ölçümün sonucuyla bağlantılı olan parametreler olarak tanımlanan kantitatif analizlerinde akreditasyonun bir parçası olan ölçüm belirsizliği hesaplamalarını değişik metotlarla gerçekleştirmektedirler. Araştırma, ölçüm sonuçlarına etki ederek değişikliklere neden olan tüm değişkenlerin kullanılmasıyla ortaya çıkan ölçüm belirsizliklerinin farklı yöntemlerle hesaplanmasını içermektedir. Bu çalışmada, sütlerde ISO 4833-1 standardına göre toplam mezofilik aerobik mikroorganizma, yemeklerde ISO 7932 metodu ile Bacillus cereus, peynirlerde ise ISO 16649-2 standardı ile Escherichia coli analizleri çalışılmıştır. Tüm veriler, International Organization of Standardization (ISO) standardı, NordVal International (NMKL) No.8 yöntemi ve EuroLab Teknik Prosedürüne (EuroLab) göre log10 tabanına çevrilerek istatistiki olarak değerlendirilmiştir. ISO/TS 19036 metoduna ait belirsizliklerin EuroLab Teknik Prosedürüne göre anlamlı (P <0.05) ISO/TS 19036 standardı ve EuroLab Teknik Prosedürünün ise NMKL No.8 yöntemine göre daha hassas belirsizlik verdikleri ortaya konulmuştur.

No abstract