The Role of Physical Testing to Support Food Quality

Of all the food tests Medallion Labs conducts each year, none is more apparent to the customer and the food producer as physical testing.

While microbial and nutritional testing quantifies the unseen, physical testing measures properties that can be perceived by the human senses. These include texture, color, density, and other attributes that affect how the consumer interacts with the product, as well as how the production equipment interacts with the product.

These physical attributes are what consumers and food producers will notice first when evaluating a food product or ingredient. Why is this important? Even if a product is safe and meets all nutritional specifications, it will be considered “bad” if the color is off, or if the texture is other than what is expected.  Or even worse, it may not even get produced and released if it or its ingredients’ physical properties deviate from what is expected to be consistent each time it is made.

Humans thrive on consistency, especially when it comes to food. We have been taught, and rightly so, that if something is off with regard to our food, something is likely wrong with it. Further, we also connect the state of being off with having an adverse effect on our health.  In general, this is a safe rule of thumb.

It is entirely understandable that people will reject food items that don't meet the expected physical standards.

The Ways and Methods of Food Physical Testing

What exactly does physical testing encompass? It can include product density and other dimensions needed to support label claims. Beyond the label, these measurements could also impact other factors that the manufacturer needs to consider, such as preparation instructions or serving size.

Additionally, physical testing will quantify texture, including hardness, strength, compressibility, shear force, and springiness.  Rheological properties can also be quantified with physical testing. This can include measuring a food product’s ability to flow (or stop flowing) under specific processing conditions or the temperature at which rheological phenomena shift.

Medallion Labs also measures particle size using a sieve screen test for a traditional look at the size distribution, but can also use laser diffraction instrumentation for high-resolution differentiation of particle sizes from ~0.5 microns up to ~1 mm. This ensures food components meet the intended specifications.

For colors, we can use reflectance or transmittance depending on the method that would work best for the food product sample.

Thermal properties such as melting point and the energy required to shift the sample from one physical state to the next are used to measure the consistency of ingredients and critical temperatures for finished products.

Physical Testing Can Protect You From Supply Chain Issues

What would cause a well-entrenched product to have issues with its physical properties? There can be a number of causes, but perhaps the most common is a supply chain issue with the ingredients.  For example, say you make a product that uses a particular powdered ingredient.

Now, suppose that your ingredient supplier upgraded its manufacturing equipment to improve output. In doing this, the mean particle size was reduced by half.

This changed the hydration rate, the rheology of the material through the process and texture of the final product.

In this example, the only thing about your product that has changed is the physical characteristics. The nutritional value and all other factors might be identical, but this seemingly minor change will create consumer dissonance. Consumers may even think something far greater has changed, and that can hurt sales and quality perception. In short, people love and trust what they have come to know and count on.

Of course, the change in particle size could also indicate other changes. Maybe the process changed other functionality, too. Maybe there was a manufacturing mistake. Maybe your order got mixed up with another company’s order of the ingredient. All of these scenarios have consequences. Some critical, some merely notable, but all need to be caught and addressed. And with physical testing, you will.

Physical Testing Can Identify Shelf Life Concerns

When your product leaves the factory, it’s blue. After a week on the shelf, it’s green. After two weeks, it’s brown. Is this normal? Is this acceptable? Is this notable?

Physical testing can help you answer these questions.

Some products are known to age and change. If the shelf life is one week, it’s not surprising the product would change color or texture after a week. But let’s say the shelf life was a year, then a color or texture change might indicate an issue. It could be caused by faulty packaging, faulty ingredients, faulty manufacturing, or perhaps, faulty shelf life testing results.

These are further reasons why physical food testing can help you identify and better understand issues when they arise.

Physical Testing Can Identify Preferences

What people like and how people define things is subjective. But with physical testing, we can align numbers to definitions.

Say you are trying to develop a thick product, perhaps a syrup of some sort. Well, how thick is thick? How you define it may not be how the market, food engineer, or business unit manager defines it.

Ultimately, it comes down to a question of market research and specific product viscosity.  You’ll rely on focus group testing of various viscosity levels to find out how “thick” should be defined. Then you’ll rely on ongoing physical testing to ensure the viscosity of your syrup product hits that viscosity mark to deliver consistent quality.

This is just one example of how physical testing can help you define product descriptions and then establish the production benchmark for your product. This same example could be applied to texture, color, and any other physical attribute.

Physical Testing Keeps It Consistent

In its most simplified form, physical testing can be used as a consistency check. It ensures the product you created is the product that is delivered time, and time, and time again.

Maintaining consistent and recognizable characteristics is core to any food product’s success. When customers purchase your food product, they are buying an expectation of the experience. It’s your duty to deliver that experience, and the people at Medallion Labs are ready to use our physical testing skills to help you deliver it. Connect with us and let’s develop a physical testing program for your food products.