Different elements work together for food to taste great and be safe for consumption.
However, there is one factor that many producers do not pay enough attention to during food processing: pH levels.
PH refers to the measurement of the acidity and alkalinity of a solution or product. It is usually measured on a scale of 0 to 14.
A pH level of 7 is considered neutral. Items with lower pH values are acidic, while those with higher ones are alkaline, which means they are caustic or corrosive.
PH measuring instruments are used to determine the acid levels that food contains during the production process.
Why pH Levels Matter in Food Production
Maintaining the required or recommended pH levels of food is crucial in the production process.
PH levels affect the look, taste, texture, aroma, and quality of food products.
For instance, during the production of yogurt, the wrong pH value can cause discolouration, excess amount of whey proteins, and excessive or inadequate tartness.
On the other hand, the incorrect pH level during the production of jelly can affect their consistency.
This element also plays an essential role in the production of cheese.
When pH levels are low, the protein crosslinks change and the casein content of the solution won’t combine with water. The resulting products are harder cheeses, such as aged cheddars, gruyere, and pecorino Romano.
However, calcium phosphate crosslinking happens when the initial pH is higher than 5.0. As a result, casein will combine with water.
Cheeses that undergo this process are more elastic and have a smoother texture. Examples of these are Swiss and cheddar.
Additionally, maintaining the correct pH level is crucial for food safety in manufacturing. For instance, a pH level of 4.6 helps prevent the growth of harmful bacteria, such as botulism, in canned or preserved meat, fruits, and vegetables.
For this reason, strict monitoring of pH levels in the production of certain foods is often mandated by federal regulations.
Measuring and Monitoring pH Levels During Food Production
There are different devices and methods used for measuring and monitoring pH levels during the production of different types of food.
The most common ones include:
1. Test strips
Litmus or test strips change their colour depending on the product’s acidity.
Analysts will dip the strip into the solution or product and compare its colour to a reference chart that maps hues to particular pH levels.
For instance, the litmus paper will turn from yellow to orange or red when the food products are acidic.
Litmus strips are inexpensive, easy to use, and disposable. They are best used for testing the pH levels of products, wherein food safety is not a significant concern since they do not provide accuracy.
2. PH meter
PH meters are the best devices for measuring the acidity and alkaline levels of food products.
Acidic foods contain high concentrations of positively charged hydrogen ions. The meter’s electrodes detect these charges, collect the positive voltage (mV) signal, and compare the reading with a reference electrode.
A 0mV indicates a neutral solution of pH 7.0. Positive mV levels indicate low or decreasing pH values, which means the product is acidic.
On the other hand, negative mV values show the presence of alkaline, which is uncommon in many food products.
When measuring food products’ pH levels, it is also vital to measure the temperature of the sample.
This is because pH values vary with the temperature.
Many pH meters come with automatic temperature compensation or ATC, allowing users to quickly check the sample’s degree of hotness or coldness and account for temperature compensation.
However, some pH meters do not have ATC. Therefore, analysts have to use a thermometer to get the temperature and include it to calculate the final pH value.
A pH meter with a built-in ATC is the best device to measure the acidity and alkalinity levels of food products during production.
A Guide to Buying pH Meters
When purchasing a pH meter, take note of the following features and tips:
● Automatic calibration and built-in ATC.
As mentioned, pH meters with ATC make it easier to test the levels of samples more accurately. Because of this, they are more convenient to use and provide reliable results as well.
Meters with automatic calibration buffer sensing also allow users to do away with adjusting them manually before using them or during the sample measurement process, or both.
● Good resolution and accuracy.
In general, pH meters with smaller numbers have better resolution and accuracy. Additionally, most federal regulations require pH readings to be reported to the nearest tenth unit.
Therefore, it is best to look for a pH meter with a resolution and accuracy level of 0.1 pH units or higher.
● Permanent or connectable probes.
PH meters come with permanent or detachable, connectable probes, both of which work well.
However, devices with permanent probes are more convenient to use and maintain. But when they reach the end of their lifespan, they are often expensive to replace since the entire unit has to be changed.
On the other hand, pH meters with connectable probes allow users to replace only the probes when needed. This can be a more cost-efficient option in the long run.
● Sealed or refillable electrodes.
Meters with removable probes usually have electrodes at their tip, which senses the pH levels in samples.
Electrodes are either sealed or refillable.
The sealed type requires less maintenance and is easier to connect and use.
However, refillable electrodes can be cleaned and thus, can last longer than sealed types.
PH plays a key role in food manufacturing. Because of this, it is important to use the right device and follow the best practices for measuring and monitoring it during the production process.