Food Sampling & Analysis - IX

Requirements and Considerations before Sampling

The following questions are some of the frequently asked questions before you go for a sampling work, which may be intended for regulatory requirements or company quality assurance or any other relevant requirements as we discuss in the previous articles. The purpose and the frequency is basically come with the planning, but when you decide the sampling plan, it is mandatory to reassure that you are doing the right thing. Thus it is very good practice to keep a check list and to follow some of the requirements given below as guide lines to get ready for a sampling expedition.

Does the person taking the sample properly authorized?

Food Authorities must ensure that the officers that they authorize to carry out food standards enforcement possess suitable qualifications, and that they have evidence of experience and competency to carry out the duties assigned to them; for example, records of qualifications, details of accompanied sampling visits and formal appraisals.

When official sampling of foodstuffs for food standards purposes is undertaken, authorized officers must additionally be trained in the appropriate techniques and be competent to carry out sampling duties. Sampling under the provisions of food legislations and the code of practice should only be undertaken by officers who meet the appropriate requirements stipulated in the code. The authorization and qualification of officers are often questioned at the beginning of a court case.

Does the type of samples that are to be taken known?

The Food Safety (Sampling and Qualifications) Regulations require authorized officers who procure samples under the Act, and who consider that the samples should be analyzed as a formal sample, to divide the sample into three parts.

A decision needs to be made whether to take a formal or an informal sample and, in the former case, whether a single part sample is necessary or appropriate and whether the containers of food samples should be opened or not. If no formal proceedings are likely to arise, then the use of a simple informal sample will probably suffice. In this case, the sample is taken as a single item or serving, with no formal requirements on the division of the sample. This is often taken as an unopened container of the food and labeled to identify its status as a sample.

The type of food involved may also affect the way in which the sample is taken, particularly samples taken under the provisions of regulations that have their own sampling provisions, as listed in the schedule to the Food Safety Regulations. For example, specific guidance is given on how to sample peanuts for aflatoxins and whole frozen chickens for extraneous water content.

Are there any legal, official or product specific sampling procedures that need to be considered before taking food samples?

Most of the Food Safety Regulations contain the basic legal provisions relating to the sampling of foods. That specifies the detailed requirements for the manner of procuring samples and the method of dealing with them. This includes their division into parts, the persons to whom parts must be provided and the notices to be given. However, the sampling, storage and analysis of some food products, analytes and even packaging materials are often controlled by specific legislation that contains its own detailed provisions which may override these general considerations. Examples include: caseins and caseinates; coffee extracts and chicory extracts; condensed and dried milk; specified sugar products; wine and spirit drinks; dairy products (e.g. extraneous water); bottled waters; poultry meat standards (e.g. water content); fishery products (e.g. chemical checks); veterinary residues in animal products; pesticides in crops, foods and feeding stuffs; nitrates; aflatoxins; ochratoxin A; lead; cadmium; mercury; 3-monochloropropane-1, 2-diol (3-MCPD); dioxins; plastic materials and articles in contact with food and mineral hydrocarbons.

The sampling procedures of the Code, however, do not have to be adhered to in the following circumstances:

Complaint food samples that are submitted by consumers or other agencies;

Food samples that are submitted to the Public Analyst or Food Examiner solely for monitoring or surveillance purposes, where there is no intention at the time of sampling that any formal enforcement action will ensue from the result;

Food samples submitted for expert opinion (e.g. foreign body identification) rather than for analysis or examination;

Food samples taken as evidence in their own right (e.g. for use-by date offences);

Samples taken under the provisions of regulations that have their own detailed sampling provisions listed in the Schedule to the food safety regulations in the concerning country.

Do you know how many, and how much sample will be needed?

The Code of Practice Guidance indicates that the quantity and nature of any sample should be such as to enable the required analysis to be made. The nature of the samples that are appropriate will depend on the purpose for which the analysis is undertaken. The quantity will vary according to the product and the type of analysis to be carried out. The Public Analyst/Sampling Specialist/Food Analyst should be consulted in case of doubt. This question of how much sample to take is regularly asked of Public Analysts. Generally, if each part of a formal sample is about 300 - 500 grams then this should be sufficient for analysis. In the case of spirits for alcohol content taken from licensed premises, the equivalent of a double shot from an optic (50ml) for each part of the sample will usually suffice although more may be required for other analysis. Again some regulations give guidance on the minimum weight of final samples.

Where the samples are pre-packed, and in relatively small containers, e.g. 250 grams, and they are not to be opened, then ideally at least 6 or 9 items should be taken as the sample and divided into the three representative final parts, with two or three food containers in each part. Generally, one sample of a specific food is taken and divided into three final parts of the sample. On some occasions multiple samples are taken e.g. to check whether the nutrition declarations on a ready meal are “typically” low by purchasing from different shops or different batches of production.

Are the correct labels, forms and paperwork, equipment, containers, utensils, and official seals available?

Each Authority should ideally have a defined system for the administration of samples. This will normally include the use of appropriately designed record forms, sample labels and laboratory submission sheets. Self-duplicating forms provide a useful means of keeping an exact record of all data. On taking a formal sample for analysis, the three final parts of the sample will need to be labeled with the name of the food, the name of the sampling officer, the name of the authority, the place, date and time of sampling and an identification number. They will also need to be placed in suitable containers and secured with a tamper evident seal. Sufficient labels, forms, containers and seals will need to be taken to the point at which the sampling is to be carried out.

Consideration also needs to be given to the correct container for the sample type. The code of practice Guidance indicates that samples of food which are not pre-packed or opened cans or packets of food should first be placed in clean, dry, leak-proof containers such as wide mouthed glass or plastic jars, stainless steel metal cans or disposable food quality plastic bags. Jars, bottles or cans should be suitably closed. Disposable food-quality plastic bags should be sealed securely after filling so that they cannot leak or become contaminated during normal handling. Samples of alcoholic drinks should be placed in glass bottles of appropriate size which have leak-proof caps and do not absorb alcohols.

The code of practice guidance indicates that the contained final parts should each be secured with a tamper evident seal. It is often useful to place the parts of the sample in a second container, such as a plastic bag, which should be sealed in such a way as to ensure that the sample cannot be tampered with, without being obvious. As the sample to be taken is not always known before going out on inspections, it may be necessary to take a selection of sample containers. It is good practice to place all sampling materials, labels etc into a sampling kit that is re-stocked after use. This gives an image of a professional approach to sampling to the seller/owner of the food.

Items and sampling equipment that may be useful when taking samples include: chopping board, can opener, knife, plastic bags, scissors, spoons, jars (note: glass is not often allowed in factories), gum tape, corkscrew, plastic gloves, ladle, protective clothing, cold box. Whatever equipment is used, it is important to ensure that it is appropriately maintained.

Is any specialized sampling equipment needed for the products concerned?

In some instances more specialized equipment might be needed to carry out the sampling and could include items such as a sampling spear, thief (specific piece of sampling equipment), temperature-monitoring device, scales, and weights. Equipment such as food processor or mincer may occasionally be useful, although it is more usual for any blending to be left to the food analyst. A camera is a useful piece of equipment for recording both the premises and details of the samples taken when appropriate.

British Standards and ISO standards contain many specifications of items of equipment those are useful during sampling, including cheese borers, dippers, and sampling spears. Some standards also specify appropriate ways of sampling for unusual shapes, e.g. round cheeses. Consideration needs to be given to the type of sample to be taken prior to setting out, to ensure that the appropriate equipment is available. It might also be necessary to take another person along to help carry out the sampling, especially if a large bulk of sample is to be taken or sub-sampled, or if there are health and safety implications, e.g. sampling from large volumes of liquid in vats, or food in silos.

Must the food sample be taken during normal working hours?

Entry into food premises, within a permitted area, may be demanded during reasonable hours, which usually means during the normal business hours of the premises in question. However, working hours within the food industry vary greatly and may not coincide with the normal hours of work. Sampling visits should therefore be planned as part of the inspection programme and timed having regard to all relevant and available information, including hours of operation, hours at which certain foods may be handled and any seasonal factors. It is desirable to sample at different times of the day at manufacturing and packing premises to ensure that samples are obtained from beginning and ends of batches etc., whether during the process of a single inspection, or by timetabling subsequent inspections differently. It is also important that food businesses are aware that they may be inspected and samples taken at any time during their working hours. You may need to consider the availability of appropriate secure storage facilities for any samples obtained outside of normal office hours.

Should prior warning of attendance be given?

The powers of entry under the Act are extensive and officers may clearly enter either business or domestic premises (as long as, in the latter case, the dwelling is in the Authority’s own area and that 24 hours notice of intended entry is given to the occupier). Special circumstances apply to police and special premises to investigate complaints and carry out inspections. At the time of seeking entry, the officer may be required to produce an authenticated document that shows their authority in the case of official sampling by public health authorities. As a general rule, inspections shall be carried out without prior warning.  Circumstances will arise, however, when prior notification of a visit will be beneficial, for example when the food business is carrying out a particular operation (a small production run of a limited line, for example).

Does the Food Analyst need to know the sample is coming?

Whilst it is not essential to let the food analyst know in advance of every sample to be submitted, in the interests of efficiency and effectiveness it is important to let your analysts have a clear idea of the numbers and types of samples and when they may be expected. It would be prudent for any unusual demand or urgent requirements to be notified to the food analysts as soon as possible. The following are examples of particular instances when it is important to liaise with the food analyst before sampling and to give an accurate indication of the number of samples expected and when they are likely to be submitted:

In the case of the delivery of large numbers of samples, or where space in freezers will need to be allocated

Where samples need to be analyzed soon after receipt, such as fresh milk for compositional analysis, or foods with labile or evanescent analytes such as sulphite or vitamin C

Test for “previously frozen” must be made by prior arrangement because samples cannot be stored for long and because test chemicals in the laboratory have a limited shelf life and may need sourcing shortly before the samples are expected.

Is a plan for sampling in special circumstances, for example postal purchases, internet purchases and deliveries needed?

Special problems arise as a result of distance selling, and most of the codes of practice guidance include a section covering this area. This presents particular difficulties in sampling because a food can be ordered by telephone, from the Internet or from literature and the first possibility of sampling does not arise until the sample arrives at its destination. Consideration has to be given as to whether a divided sample is sensible or practical. For instance, if Scottish salmon were ordered by phone and delivered, consideration needs to be given as to whether it can be divided and whether a part of the sample can be returned to the seller. Also, what changes might take place to that part of the sample in transit. It might be concluded that division into three parts is not practical and a single part sample used. The Authority needs clearly to consider the arguments in the case of each food type and needs to be able to justify not dividing the sample in the event of a court case. However, where a sample can be divided and returned without fear of the part changing, e.g. vitamin tablets, it might be safer to return a part of the sample to the seller/owner, although it is advisable to discuss these arrangements with the seller/owner beforehand.

Is any specialized clothing required?

The Food Safety Act and Code of Practice requires authorities to provide officers with clean protective clothing including headgear consistent with good industry practice. It also requires officers to wear it, and to give details of their health status when requested to do so. Many companies will have their own hygiene requirements for entering food production areas and will normally provide sampling officers with the appropriate clothing. These often include overalls, hairnets, hats, overshoes, wellington boots, beard snoods etc. It is necessary to comply with the hygiene requirements of the company concerned and this often includes a signed declaration of the officer’s state of health.

For sampling in shops, the provision by the authority of clean white coats, white hat and disposable gloves is good practice. In certain instances personal protective equipment may be needed when sampling. For instance, when dealing with the cutting of meat, the use of protective clothing such as chain mail gloves might be necessary. Other protective items might include protective boots, ear defenders, safety goggles, blue plasters and a small first aid kit. The health and safety of sampling staff should be considered at all times and they should also comply with the hygiene requirements of any food company concerned.

Will the samples be purchased or taken?

It is for the authorized officer to decide, in accordance with the policy of their Food Authority, whether to purchase the sample, or if powers to take it should be exercised. Officers have the power to:

Purchase a sample of any food, or any substance capable of being used in the preparation of food (e.g. food additives);

Take a sample of any food which; appears to be intended for sale, or to have been sold, for human consumption, or they find on, or in, any premises which they are authorized to enter.

Take a sample from any food source, or a sample of any contact material (e.g. plastic packaging), which is found on, or in, any such premises;

Take a sample of any article or substance which is found on, or in, any such premises and which the officer has reason to believe may be required as evidence in proceedings under any provisions of the Act or of regulations or orders made under it.

It may be beneficial for a sample to be obtained by ‘test purchase’ (i.e. by buying an item of food as an ordinary purchaser without first announcing your identity as an authorized officer to the seller).

Reference

http://multimedia.food.gov.uk/multimedia/pdfs/samplingguidancepart2.pdf