Ready to Eat

When it comes to Ready to Eat foods, quality control can be challenging with a host of competing objectives. The product must offer consistency to the consumer as well as be safe to eat, “long” lasting and be able to withstand a variety of environmental conditions. The best way to achieve all these goals is with objective, measurable standards in the production process and with quality control testing. 


How do I extend my shelf-life while keeping my ready to eat meals tasty and appealing?

In recent years there has been an explosion in pre-packaged and ready to eat meals that are fresh and only require heating. This has brought a huge challenge for the QA/QC professional, needing to ensure everything from freshness to nutritional content to the absence of allergens. 

The principle is simple – ready to eat products and pre-packaged meals have a huge number of failure points, if these are not being objectively tested, then there is no knowing where failure is going to come from. When sending Ready to Eat meals to customers, the viable shelf-life can be extended by as much as 4x with the use of modified atmosphere packaging - without needing to resort to the use of preservatives! 

However, if this is being done, it needs to be ensured that the concentrations of Carbon dioxide (CO2) and Nitrogen (N2) going into the package are correct by using a gas mixer. After this, any cautious Quality Control professional would like to ensure that the sealed product has the correct level of gases (usually low Oxygen, 30-60% Carbon Dioxide and Nitrogen), in the correct concentrations in the headspace. This can be done with the Dansensor range of Residual Oxygen (RO) Analysers, which includes the Dansensor CheckPoint 3 for at line use or the Dansensor CheckMate 3 for lab use. 

The entire gas flushing process is a waste of time and resources if the seal integrity of the package is not being checked and monitored. (i.e if the package is not being checked for leaks). The most common method of leak detection is the destructive water bath (Dansensor LeakPointer H2O). The challenge with a water-bath, however, is that it is destructive: the packaging must be disposed of after testing. If, instead, the preference is to have total quality assurance and still be able to sell the product after testing for leaks then non-destructive leak testing is route to take. Principle methods of non-destructive package integrity testing include pressure decay and gas detection. Instruments that have this capability are the Bestech range and the Dansensor LeakPointer 3 respectively. 

How can I make “allergen free” label claims?

One of the most common reasons for the Ministry of Primary Industries (MPI) Product Recall notices relates to the presence of undeclared allergens. Ready To Eat products, due to their multi-component composition, are more susceptible than most to this issue. The best way to stop undeclared allergens from slipping through and causing a product recall is by testing with the simple lateral flow or “dip tests”. These can be used both directly on the product or by swabbing the preparation surface for allergen proteins. Mätt Solutions offers a range of easy-to-use allergen testing solutions that cover more than 95% of all allergen related issues. 

What impact does Water Activity (aW) have on Shelf-Life?

“Ready to Eat” can include more than entire pre-packaged meals.  The segment extends to shelf stable meat products, (such as sliced ham or bier sticks) and similar packaged foods.  For all of these, water activity is going to be a key control point for safety and quality. Many also rely on pH to prevent pathogen growth and the smart food safety professional will tap on the apply the principles of hurdle technology to create a safe and long-lasting product. 

Uncooked, ready to eat snacks are prone to not only pathogen growth, but also mould contamination. In this regard – water activity (aw) can be one of your biggest safeguards. If aw is below 0.85? then bacteria will not have enough available water to grow, for control of mould however, the water activity must generally be below 0.85. To monitor aw, an accurate instrument that provides fast and reproducible reading is required. 

For this, the Aqualab 4TE is highly recommended. Using a dew point mirror sensor it can provide aw readings to an accuracy of 0.003 aw with a short 5 minute read time.  For volatile aw samples there is the Aqualab TDL2. If fast, at line readings are needed there is the Aqualab AQ3 – Aqualab’s “1 minute water activity meter” combined with fast moisture readings. 

When the combined effects of pH and aw are being used for product safety, pH must be measured, controlled and verified, along with proper records being kept for the auditor.  Which pH meter works best will depend upon the product matrix. This includes whether a portable hand-held (dip, probe or spear) pH meter is used or whether a bench top with specialist pH probes that can be changed via a BNC connector are the better option.

Is there a way to efficiently monitor and data log temperature of the full manufacturing to consumer journey?

Real time monitoring of the freezer, chiller, production and delivery process is key to ensuring safe production while maintaining optimal temperatures and humidity for product safety. Monnit have a range of temperature, humidity and “more” (up to 85 other sensors) that enable accurate monitoring of the freezer, chiller, production and delivery process with real time alarms in the form of emails or phone alerts.

Is there a fast way to perform shelf-life testing/verification on Ready to Eat foods?

Mätt Solutions offer shelf-life testing services that look at the product's "complete picture", considering all its aspects to determine when and what ends the shelf life for a Ready to Eat” products. Packaging provides protection from extremes in light, temperature, humidity and oxygen all of which will reduce shelf-life if not controlled. To perform an accurate shelf-life test, it is imperative to expose the product to different conditions to know when and why it fails.

Mätt Solutions have a wide selection of chambers and simulation set-ups to test these extremes and help determine the shelf-life and durability of Ready To Eat foods by offering both accelerated and real time shelf-life studies as applicable. At the end of the trial, a comprehensive report is provided that states the actual shelf-life of the product, outlines reasons for failure and in most cases recommends ways to improve. This report tends to be a requirement by most supermarket chains and is well received by auditors and MPI (Ministry of Primary Industries) 


What is the benefit of gas flushing a ready to eat meal?

Using the correct gas mix with a ready to eat meal can keep the product fresher for longer. Preserving taste, smell, appearance and product safety.  

If I gas flush, how much longer will a ready to eat meal last?

Research indicates that gas flushing can extend the shelf-life of a fresh, chilled product by as much as three times. 

My products are too valuable to leak test using a “destructive” water-bath, what should I do?

It is very easy to conduct a water-bath or submersion test for leaks. But because the product is immersed in water you cannot sell it after testing – even if there are no leaks. The solution is to use a non-destructive leak test. This might be by analysis of escaping gas or by pressure decay. 

What shelf-life should be expected from a ready to eat meal?

The shelf-life of a properly packaged (and chilled), ready to eat meal can be anywhere from a few days up to 2-3 weeks. Often, because of the multi-component nature of these types of products, the only effective way to determine shelf-life is with empirical shelf-life testing that includes BOTH food safety and food quality. 

What modified atmosphere gas mix should be used for ready to eat meals/heat n eat packaged meals?

A rule of thumb when gas flushing Ready to Eat meals is to use a 30% CO2/70% N2 mix.  This includes meals containing fish, poultry, pasta and vegetables.  It’s important to note however that this should be checked and validated that this will extend shelf-life.