Food manufacturers need to maintain retention samples of batches produced, but this can be quite a challenge, especially since food safety standards offer little guidance on the topic. In this article, we explore why retention samples are essential and provide practical tips for implementing an effective retention sample system in your food business.
What do the Food Safety Standards say?
The SANS 10049:2019 standard, titled “Food Safety Management Requirement for Prerequisite Programmes,” is a crucial resource for local manufacturers implementing the necessary prerequisite programs (GMPs). According to Clause 8.14 of this standard, “The final food product shall be sampled and stored for retention purposes.” However, the standard does not specify the exact procedures for this. Clause 5.6.3 of the BRCGS Global Standard Food Safety Issue 9 Interpretation Guide also emphasises the importance of retention samples, stating that “Shelf-life testing may be critical to product safety; for example, where the product is susceptible to the growth of pathogens. Therefore, after the initial shelf life is determined (see clause 5.1.4), the site is expected to have a programme of ongoing shelf-life validation and verification across its range of products or product types. To achieve this, samples should be retained from some or all production runs.”
What food retention samples are needed?
There are four main types of retention samples, which we will be looking at in more detail below.
- Shelf-life validation samples,
- Shelf-life verification samples,
- Raw material retention or reference samples, and
- Final product batch retention samples.
- Shelf-Life Validation Retention Samples
Shelf-life validation trials scientifically confirm that product safety, legality, and quality are maintained within acceptable limits throughout the expected shelf life.
Before launching a new product commercially, you will need to conduct a shelf-life study to determine the achievable shelf life. This process involves producing a pilot batch in the production plant by simulating the same manufacturing conditions, using the same production equipment and final product packaging, then storing it under the same environmental conditions intended for its shelf life and testing the product at regular intervals to ensure it meets microbiological, analytical, and organoleptic (legal, food safety, and customer) specifications. Based on this scientific study, you can then determine a conservative shelf life with a built-in safety margin for the final products.
Note: Accelerated shelf-life testing may also be considered, where certain conditions are amplified to speed up the study. We recommend that you consult the expertise of a food testing laboratory to help you with your shelf-life study.
- Shelf-Life Verification Samples
Shelf-life verification retention samples are samples taken from the final packed product and stored for the entire duration of the product’s shelf life under similar conditions to those the product will experience once released into the trade. These samples are especially relevant for products stored at chilled or ambient temperatures.
The aim is to verify that the final product achieves the intended shelf life as declared on the label/product specifications (based on the initial shelf-life validation study) and to identify any potential shelf-life problems that may occur in the market. This process involves monitoring the product at set intervals (e.g. middle and end of shelf life) for signs of deterioration, such as changes in taste, smell, colour, and texture. Microbiological tests can be conducted by extracting a portion of each sample and compiling a homogenous composite sample of production batches of the same product produced on the same day. This sample should be tested in a laboratory for the presence of an indicator organism, such as E. coli. If an indicator organism is detected in the composite sample, test the individual batch retention samples to pinpoint the source of contamination.
Note: The number and degree of testing of retention samples depend on factors such as legal or customer requirements, the product’s susceptibility to pathogens, the number of batches produced daily, and the available space and resources for managing the sample retention program.
- Raw Material Retention Samples
Raw material retention samples may also be referred to as reference samples. If your raw material risk assessment identifies the need to retain samples due to legal or customer requirements, food fraud risks, recall incidents, or customer complaints, these samples should be part of your raw material acceptance protocols linked to your Supplier Approval and Monitoring procedures.
Note: The volume of the sample and the duration of the retention period will depend on the types of analytical or microbiological tests required and the final product’s shelf life. Although food safety standards do not specify the retention period for samples, it’s a good idea to store them for slightly longer than the specified product shelf-life.
- Final Product Batch Retention Samples
Depending on the type of products manufactured, based on a risk assessment of the product, where practical and if you have sufficient space to do so, we recommend storing a small sample of each batch in a freezer or chiller as an additional backup for further analytical or microbiological testing in the event of an incident investigation.
Suggestions for a sample retention system
- Label each sample with a legible, permanent sequential sample number that won’t smudge.
- Maintain a register of all your samples, including the sample number, product name, batch number, date, sample location, and date for sample removal from the system.
- Provide a dedicated area with shelving, crates, or boxes for storing your samples.
- Implement a FEFO (First Expired First Out) system for your samples.
- Shelf-life verification samples should be stored in the final product packaging. Raw material or batch reference samples should be stored in sterile, leak-proof, airtight containers that are compatible with the product such as sterlie ziplock bags, urine sample jars, glass jars with metal screw caps, food grade plastic jars, etc.
- Group the day/week or month’s samples into one container or bag or use different coloured stickers or closures to easily identify the day, week, month, or sample type.
Top Tip: Consider a retention sampling system as a filing system. As samples expire and need to be discarded, new space becomes available for new retention samples. We recommend using the “reverse snake method,” where the oldest and newest products “chase” each other. When an old retention sample is taken out, it can be replaced by the newest retention sample.
In conclusion, although food safety standards require shelf-life verification retention samples, they do not provide clear guidelines on how to implement such a system. You will therefore need to develop your own system based on the risk of your product, legal and customer requirements, and what is practical to implement and maintain in your facility. If space allows, consider retaining samples of sensitive raw materials and final product batch reference samples in addition to your shelf-life verification samples. These can be invaluable when dealing with customer complaints or food safety incidents. Above all, ensure that you assign a dedicated staff member who will manage and control the sample retention system meticulously.
For more information on retention samples, be sure to download our eBook here: https://www.entecom.co.za/retention-samples-why-do-you-need-them/
How can Entecom help you?
Entecom is a FoodBev SETA Accredited training provider offering a wide range of credit-bearing SETA Accredited Skills Programmes starting from Level 1 and progressing through to Level 5. We also provide customised in-house workshops, aligning content with your company goals and operational requirements to help drive improvement. Our digital compliance solution, Entecom online (EO), is also designed to make food safety compliance easier, faster and more affordable. Contact us at info@entecom.co.za today to discuss your compliance needs.