Regular pH testing is extremely important in the production of food to ensure that the product meets the required standards of quality, safety and freshness. All major food and beverage producing companies like McDonalds and Coca Cola as well as canned food producers, dairies, makers of jellies jams and sauces, foodstuffs for freezing and a multitude of others use pH testing.
There are various reasons why pH testing needs to be done in the food and drink industry, here are some of them:
When a food being produced becomes too acidic or not acidic enough, it effects the flavor so the pH has to be strictly controlled within tight limits. This ranges from small mom and pop jam-making concerns right up to major food manufacturing process plants making the likes of cheese and coffee and breweries making beer. If a food has too high an acid content it will taste sharper than it is supposed to be.
Ensuring food safety is of prime concern to manufacturers so pH has to be tightly regulated. Early detection of food going off and beginning the rotting process can be detected by a change in pH. It is also used to check freshness of milk, butter and yoghurt in the dairy sector. pH is particularly vital in those industries where there are live cultures in the process such as cheese and yogurt making, yeast for bread, or the fermentation of beer and wine.
Strict quality controls exist throughout the food and drink industries and monitoring pH plays a vital part in ensuring consistent quality. For example in jelly making the jelly sets within a specific pH range so any deviation means the resultant product is either too watery or too hard.
Testing procedures vary according to what the food or drink being tested is, sometimes a sample can be removed and tested in a lab environment or in-line monitoring can be put in place for larger scale operations. Testing can be done on such as meat and cheese samples by inserting a probe directly into the food.
pH Meter Selection For Food Applications
The uses and applications of pH meters are wide and varied, similarly the range of meters available to buy is extensive. As a buyer you have to try and ensure that the pH meter you are getting is going to be the right fit for your needs and will do the job you need it to do.
The following is a check list that will help you decide what meter is best suited to your needs.
It is arguably the most important factor in any buying decision, whatever meter you buy has to be within your budget or you just won’t be able to buy it. One way to get best value for your money is to make sure you purchase at the best price available.
– Accuracy and reliability
You need your meter to be accurate enough to ensure that what you are measuring stays within the limits required for the process. Further, the meter needs to be reliable so that it gives consistent readings each time. For testing food acidity, an accuracy of 0.01 to 0.02 units is usually preferable though it might be possible to use a pH meter with an accuracy of 0.2 units for foodstuffs with a pH not in excess of 4.0. A pH meter that gives less accurate results being used on food with a pH of higher than 4.0 can lead to foods with unsafe levels of 4.6 or higher going on sale.
– Durability and Longevity
It kind of goes without saying but your pH meter needs to be tough enough to cope with the situation that you’re going to use it in. If you need to measure pH outdoors it has to be able to withstand adverse weather and temperatures that it will encounter and be resistant to dust and dirt.
You need to bear in mind when choosing an electrode for food use that oil can clog up the electrode and render it useless. If there isn’t a lot of oil involved a standard glass electrode can be used. If you are going to be probing solids like meat or cheese you will need a special electrode for that too.
Your pH meter has to be calibrated in order to make sure you get accurate readings, get a meter which has at least 2-point calibration. To avoid confusion the solutions are color-coded, red for the pH 4, yellow for the pH 7 and blue for the pH 10. These are reference solutions with known pH values that you use to test your meter against. For testing in the food industry the pH 4 and pH 7 solutions will usually be sufficient for calibration.
– Automatic Temperature Compensation
In the food and drink industry, you are going to need a pH meter with automatic temperature compensation. Food production is heavily dependent on temperature in the manufacturing process and as your pH readings will be affected by temperature, they need to be continuously monitored. Without having automatic temperature compensation built into the meter, you would need to let the food cool off before measuring pH – not a practical solution in a fast-paced environment.