vegetables - J.S. Hamilton

The safety of food is a priority not only to consumers and manufacturers, but also to legislative bodies. That is why laws determine the necessary safety criteria that all food products need to comply with. In this article, we discuss those related to the microbiological parameters of food.

Regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January 2002 laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety, as amended, which is the basic piece of EU legislation formulating the principles and requirements of European food law, prohibits the placing on the market of food that is not safe. Food business operators are obliged to withdraw unsafe food from the market.

Commission Regulation (EC) No 2073/2005 of 15 November 2005 on microbiological criteria for foodstuffs, as amended, lays down harmonised safety criteria for the evaluation of food products as regards pathogenic micro-organisms to increase the protection of public health and to avoid divergent interpretations. This regulation and subsequent amending regulations establish harmonised food safety criteria for certain pathogenic micro-organisms. These criteria also serve to validate and verify HACCP procedures and other hygiene control measures.

In the light of the legal acts cited, a distinction is made between:

1. food safety criteria, i.e. requirements determining the acceptability of a product or a batch of foodstuff, applied to products placed on the market. This group includes:
  - Salmonella (including serogroups Typhimurium and Enteritidis),
  - Listeria monocytogenes,
  - Cronobacter,
  - Escherichia coli,
  - Shiga-toxin producing E. coli (STEC) O157, O26, O111, O103, O145 and O104:H4,
  - Staphylococcal enterotoxins,
2. process hygiene criteria, i.e. requirements for the acceptance of a functioning production process. They do not apply to products placed on the market. These criteria determine the indicative value of contaminants, exceeding which corrective actions are necessary to maintain the hygiene of the process at the level compliant with the food law. This group includes:
  - Aerobic bacteria count,
  - Enterobacteriacae,
  - Salmonella,
  - Escherichia coli,
  - Campylobacter spp.,
  - Coagulase-positive staphylococci,
  - Bacillus cereus.

The microbiological laboratories of J.S. Hamilton Poland offer comprehensive hazard monitoring at every stage of production, including environmental control, using the methodology specified in Polish standards, harmonised with European and ISO standards.

In addition to the tests included in the above criteria, we also perform the following microbiological analyses:

Bacillus subtilis,
Bacillus coagulans,
Listeria spp.,
Cronobacter spp.,
Alicyclobacillus spp.,
Moulds and yeasts,
Lactic acid bacteria,
Acetic acid bacteria,
Aerobic psychrotrophic microorganisms,
Spore-forming and non-spore-forming anaerobes, meso- and thermophilic,
Clostridium perfringens,
Clostridium botulinum,
Enterococcus,
Pseudomonas,
Characteristic bacteria in yoghurt,
Osmophilic moulds and yeasts,
Durability testing by thermostat test.

In addition to classical, standardised methods, J.S. Hamilton Poland laboratories have validated and accredited rapid alternative methods, based on the BAX® automated system based on the detection of a specific DNA sequence characteristic for pathogenic microorganisms. These methods are applicable to testing food, environmental samples from food production and trade areas. Using the BAX® system, we can determine the presence of such pathogens as:

Salmonella,
Listeria monocytogenes,
Escherichia coli O157:H7,

and for meat and meat products, vegetables, fruit and sprouts:

Shiga-toxin producing Escherichia coli (STEC) O157, O26, O111, O103, O145 oraz O104:H4.

As part of its services, J.S. Hamilton Poland also offers fast and precise detection of viruses present in ready-to-eat foods, which are not subjected to heat treatment during preparation and do not require heat treatment before consumption. These viruses mainly include:

Hepatitis A virus,
Noroviruses (also known as Norwalk viruses).

Using RT-PCR (reverse transcription PCR) we can determine their presence in matrices such as:

Fruit and processed fruit,
Vegetables and processed vegetables,
Environmental samples from the food production and marketing area.

Within the scope of accreditation, we also carry out microbiological analyses of drinking water, as well as tests of microbiological purity of packaging intended for contact with food.

Mycotoxins are secondary metabolites of certain moulds, mainly Aspergillus, Penicilium, Fusarium and Alternaria. They can occur in almost all products consumed by humans and animals. They are toxins resistant to technological processes (e.g., cooking, frying, baking, distillation, fermentation) and are most frequently found in products of plant origin such as: cereals, cereal products, vegetables, nuts.

The development of moulds and the mycotoxins they produce is influenced by the temperature and humidity of the air, the water content of the raw material and the degree of maturity of the plants. In addition to the high health risk, mycotoxins can cause serious economic losses. This may be the result of unfavourable weather conditions during the growing or harvesting period or of incorrect storage. It should also be taken into account that, with changing environmental conditions, a single mould species can produce several mycotoxins.

According to FAO estimates, mycotoxins may contaminate up to 25% of the world’s food production, and complete elimination of mycotoxins is an essentially unattainable goal. More than 400 mycotoxins are currently known, of which about 20 pose a serious threat to crops that are a source of food for humans and animals. In food and feed, the most commonly determined mycotoxins are:

aflatoxins B1, B2, G1, G2 (aflatoxin M1, mainly in milk and products).
ochratoxin A,
trichothecenes (e.g. deoxynivalenol, T2, HT-2),
fumonisins B₁, B_2,
zearalenone,
patulin,
ergot alkaloids.

Mycotoxins can form at various stages of food production, from plant vegetation, through harvest, to the storage of the harvest or even the final product. During the vegetation period, phytopathogenic fungi strains, e.g., of the genus Fusarium, are the source of mycotoxins, whereas during storage, saprophytic fungi predominate, especially of the Aspergillus and Penicilium genera, whose mycotoxic activity depends on improper storage conditions, which may result in production of aflatoxins, ochratoxin A or citrinin (so-called storage mycotoxins).

Commission Regulation (EC) No. 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs, as amended, sets maximum levels for mycotoxins which pose a potential risk to human health and life. In addition to the most commonly determined ones mentioned above, maximum levels have been set for citrinin.

The study of mycotoxins in food and fodder was of particular interest to the J.S. Hamilton Poland Laboratory as early as in the 1960s, immediately after the first reports of the threat in England, where mass epidemics of poultry (“turkey X disease”) caused by mouldy fodder were reported. Over several years, our laboratory developed a method for the determination of aflatoxins using high-performance liquid chromatography. As chromatographic techniques developed, J.S. Hamilton Poland Laboratory validated and accredited methods of analysis of mycotoxins subject to monitoring, using various chromatographic techniques:

high performance liquid chromatography with fluorimetric detection (HPLC-FLD),
liquid chromatography coupled with tandem mass spectrometry (LC‑MS/MS).

The laboratory also performs tests on herbal raw materials developed based on the requirements of the European Pharmacopoeia for the determination of aflatoxins B1, B2, G1 and G2 and ochratoxin A.

Contact our team today to learn more about our methods – or to schedule tests with J.S. Hamilton.

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