What are the best food sampling techniques for ensuring representativeness?

2 Sampling methods

When sampling food products, the method used depends on the physical state, shape, size, homogeneity, and distribution. Random sampling is a popular choice; it reduces bias by selecting samples at random from the entire population or batch, using a random number generator or table. Alternatively, stratified sampling divides the population or batch into subgroups based on relevant characteristics such as location, time, or quality level. Systematic sampling takes samples at regular intervals from the population or batch with a fixed starting point and constant step size. Lastly, cluster sampling divides the population or batch into clusters of similar units and then randomly selects some clusters to sample all or some of their units. This method can save time and cost but may introduce bias if the clusters are not representative of the whole population or batch.

3 Sampling tools

When collecting and handling samples, it’s important to choose tools that are suitable for the type and size of the sample, clean and sterile, and do not alter or damage the sample. Additionally, they should be easy to use and maintain. Scoops, spoons, spatulas, or knives are ideal for solid or semi-solid samples like grains, fruits, cheeses, or meats. Pipettes, syringes, or tubes can be used for liquid or viscous samples such as juices, sauces, or dairy products. Cork borers, augers, or drills are best for core samples like nuts, seeds, or cereals. Swabs, wipes, or filters are useful for surface samples like skins, peels, or packaging materials.

4 Sampling procedures

When collecting and handling samples, it's important to follow standardized or validated protocols to ensure quality and safety, and minimize the risk of errors or contamination. Labeling the samples clearly and accurately with information such as date, time, location, product name, batch number, and sample code is essential. Additionally, the samples should be sealed in appropriate containers such as bags, bottles, or jars that are clean, dry, and airtight. Furthermore, it is important to store and transport the samples under suitable conditions such as temperature, humidity, or atmosphere that prevent them from spoiling or deteriorating. Finally, analyzing the samples as soon as possible or preserving them through freezing, refrigerating, or adding preservatives is necessary until they are ready for analysis.