The Science and Law of Food Testing

The scientific credentials of anyone working within food testing need to be underpinned with knowledge of the current and emerging regulations. This means keeping a breast of any changes to food quality standards. The all too recent horse meat scandal is a reminder of why food testing is needed with a global food supply chain.

Food testing labs fall into two key disciplines:

 

  • Food microbiology testing
  • Food chemistry testing

 

Both areas of food testing are about providing reliable, accurate results to make foods safer. Ensuring they meet the necessary statutory requirements and protect the consumer.

Food microbiology testing

Microbiology food testing is specifically for the identification of microorganisms which causing food spoilage and foodborne illness or where food producers’ use microorganisms to in food production, for example cheese making.

The most common applications of microbiology in food testing are:

• Shelf Life Determination – confirmation of the stability of a food product based upon storage conditions, time and temperature. The shelf life determination allows food producers to confidently set a Sell By Date or Use By Date.

• Water Testing – testing water is safe for human consumption within a food factory or manufacturing site. Because water a raw material and should be tested and analysed accordingly.

• Legionella Testing – testing water for the specific presence of Legionella bacteria, especially the most pathogenic (disease-causing) strain of Legionella bacteria is Legionella pneumophila group.

• Environmental Hygiene Monitoring – advice on how to set up food factory environmental control and monitoring plans to help meet the specifications required for good food factory environmental hygiene Helping reduce levels of contamination in finished products, leading to improved quality, fewer batch rejections and lower risk of product recall.

• Microbial Quality Determination – used to assess the microbiological quality of the end product, or an ingredient, or even the cleanliness of a food contact surface.

• Pathogen Determination/Identification – analysing and testing for food pathogens which cause illness in humans either by infections such as Salmonella, Campylobacter and pathogenic Ecoli or in toxications such as Bacillus cereus, Staphylococcus aureus or Clostridium botulinum.

Food chemistry testing

Food chemistry testing is focused around nutritional values and determining the composition of food products. Identifying the presence of additives or contaminants and is generally used to ensure food and drink products meet consistent standards and quality. It can also be used to provide accurate data to meet regulatory and consumer requirements, for example food labeling.

The most common applications of food chemicals testing are:

• Group 1 Nutritional Testing – The minimum declaration permitted on food packaging and labeling is a “Group 1” declaration, this covers:

– Energy (kJ and kcal)

– Protein (g)

– Carbohydrate (g)

– Fat (g)

• Group 2 Nutritional Testing, including AOAC Dietary Fibre – the Government recommends that Group 2 information be given on all foods, on a voluntary basis, as this gives consumers information on the key health-related nutrients. Information declared should be expressed as g/100g or g/100ml.

– Energy (kJ and kcal)

– Protein (g)

– Carbohydrate (g)

of which:

– Sugars (g)

– Fat (g)

of which:

– Saturates (g)

– Fibre (g)

– Sodium (g)

• Meat and Fish Contents – There are limits on the presence of connective tissue and the amount of fat associated with lean meat. Analysis of meat content and collagen can provide you with figures for Nitrogen, Protein, Ash, Moisture, Fat, Carbohydrate, Apparent Meat with and without Fat and Energy Values in Kcals and Kjoules.

• Meat and Fish Speciation – Once flesh is removed from the carcass it is not always easy to visually identify the different species. The more processed the meat or fish, the less recognisable it becomes from its original species. It is at this stage that adulteration and contamination can occur. The identification of animal species is performed for a variety of reasons, both economic and ethnic, to prevent the substitution of meat with unsuitable or inferior species, or in religious communities where a particular meat is prescribed.

• Elemental Analysis – testing on the sixteen minerals present in food stuffs required to support human biochemical processes. These sixteen elements are divided into 2 categories; Quantity Elements Analysis and Essential Trace Elements Analysis.

Quantity Elements Analysis

– Sodium (Na)*

– Potassium (K)

– Magnesium (Mg)

– Calcium (Ca)

– Phosphorous (P)

– Sulphur (S)

– Chlorine (Cl)

* Salt Testing is an important part of nutritional declarations.

Essential Trace Elements Analysis

– Manganese (Mn)

– Iron (Fe)

– Cobolt (Co)

– Nickel (Ni)

– Copper (Cu)

– Zinc (Zn)

– Molybdenum (Mo)

– Selenium (Sel)

• Heavy Metals – Heavy metals are widely present in the environment, both from natural sources and human activities. These metals are dangerous as they tend to accumulate in the food chain. As the top consumer of the food chain, humans are subject to highest risk of heavy metal poisoning. The most common heavy metal food tests are:

– Arsenic (As)

– Cadmium (Cd)

– Lead (Pb)

– Mercury (Hg)

– Aluminium (Al)

– Silver (Ag)

– Tin (Sn)

• Genetically Modified Organisms (GMO) Screening – the analysis and legislative aspects of genetically modified (GM) foods and food products. GM Foods are monitored for safety by the European Food Safety Authority and other bodies and foods are checked for toxicology, allergic reaction and nutritional properties on both raw materials and finished products.

• Vitamins – claims of vitamins in foods are now commonplace. The legislation of consumer foods, food products and drinks ensures the consumer has accurate information.

Whether with natural vitamins or fortified with vitamins, products are closely monitored and accurate vitamin testing is essential to ensure that declared levels are correct, especially if a company is making a claim about a product.

• Water Activity (ERH), pH – water as an ingredient in foods and food products was the earliest form of food preservation. The availability of water for microbial growth and biochemical reactions may be controlled by dehydration, freezing and the addition of solutes such as salt and sugar, thus having the potential to prolong shelf-life of a product.

Food testing water activity is used for compliance of government regulations, CFR, HACCP and other food safety programs and helps food producers control and predict microbe activity.

• Allergens – since November 2005, food labelling regulations in the UK and Europe have insisted that allergens deliberately added to pre-packed food and food products must be labelled with allergen information. For example ‘gluten’ and ‘nuts.’