How To Test The Shelf Life Of Dairy Products
Shelf life is a vital measure of food quality and freshness. It is the length of time that a product meets the quality expectations of consumers.
Consumers want their food to be fresh. 54% of British consumers say that the quality of a supermarket’s fresh food is the most important factor in choosing to shop there.
Fresh food includes dairy products. These products continue to ripen during distribution and display. Their chemical and sensory products change during the period that the shop markets them. Therefore, their shelf life is a critical factor, particularly when looking at long life UHT style beverages such as long life milk and shakes.
How should you test the shelf life of dairy products?
Why is it Important to Test the Shelf Life of Dairy Products?
Keeping long-life dairy products fresh requires that they retain certain characteristics over time, such as:
Colour, especially whiteness
Visual texture and spreadability
Milky aroma and flavour
Low acidity.
These are sensory elements affecting how people perceive the freshness of dairy products. But these elements also undergo natural changes during a product’s lifecycle.
These changes are the result of lipolytic and proteolytic processes. Lactic acid bacteria exist naturally in dairy products and take part in these fermentation processes.
Changes to flavour and visual appearance are especially important as they can influence consumer choice and brand reputation. Without testing the shelf-life of food, producers and manufacturers cannot guarantee the quality and safeness of products sufficiently to reassure retailers and consumers.
What Factors Influence Food Shelf Life?
We’ve already seen how, in dairy products, natural changes occur that can influence their shelf life.
However, the quality of most food products decreases over time.
The main cause of spoilage of food is the growth of bacteria. Most spoilage issues come from psychotropic bacteria. These bacteria can grow quite rapidly even at refrigerated temperatures.
Loss of freshness is the point at which the product is not as good as when it was first produced or packaged, however this can be difficult to identify. There can be differences between actual spoilage and what consumers consider acceptable levels of freshness.
Spoilage affects products when they start to smell or taste off-flavour, but the threshold of this can vary from consumer to consumer. But, as the quality of products deteriorates during storage, so, ultimately, their appeal to customers declines.
Customers who are satisfied with the freshness of a store’s food will spend 74% more than those customers who are dissatisfied. The process of change affects dairy products gradually, and it can be quite subtle.
This is why analysing and predicting the shelf life of UHT milk and other long-life dairy products is such a vital part of food manufacturing, distribution and retail.
How to Test Monitor the Shelf Life of Food
Commonly used methods for testing the shelf life of food include:
Direct – real-time studies involving the storage of products in conditions similar to real-world circumstances, to estimate viable shelf lives
Challenge testing – introducing pathogens or microorganisms into the food during production to study the potential effects of such contamination in actual storage conditions
Predictive microbiology – using statistical and mathematical models to predict the behaviour of foodstuffs in storage conditions
Accelerating shelf life – modifying conditions such as temperature to accelerate their effects on food behaviour
Survival – using consumer responses to gauge the acceptability of a product’s physical characteristics based on varying dates of manufacture.
Predicting Shelf Life of Dairy Products
One specialist method for predicting the shelf life of dairy products is by testing for adenosine triphosphate (ATP).
This applies to UHT milk, other long-life dairy beverages and can also be used to test some non-dairy products such as almond milk.
This is a fast, real-time alternative to microbiological testing. It involves bioluminescence testing for rapid screening of finished UHT and ESL (extended shelf life) products.
ATP is a bio-marker of microbiological quality. Testing for it can give early indications of a product’s quality.
Advances in this form of testing mean that compared to traditional microbiological tests, it is much faster. This helps to extend production cycles and increase efficiency in predicting shelf lives through testing.
The Charm Epic ATP System automates ATP testing, and its supporting software gives provides real-time analysis and identifies trends. It can screen beverages for shelf life in as little as 24 to 26 hours.
Why Dairy Testing Supports Shelf Life
Even dairy testing that does not have a specific focus on shelf life is valuable in helping to ensure products stay fresher for longer.
The quality of raw milk products and their composition contribute to their shelf life and overall performance.
Consequently, various dairy testing products help dairy farmers ensure they can maximise the quality of their milk yields.
How Effective is Your Dairy Testing?
Reliable and rapid testing of dairy products and herds is essential for commercial success and maintaining consumer appeal.
For more information, please contact us.