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Brine, a high-concentration aqueous solution of one or more salts, is widely used in the food industry for preservation purposes. The addition of salt to foods such as meat, fish, and cheese reduces the water activity of the product and prevents microbial growth, thereby increasing its shelf life.
However, measuring the pH of brine samples can be challenging due to various factors, such as high protein and salt content, which can affect the performance of conventional pH sensors.For instance, in the case of canned food, using a sensor with a spherical sensing membrane makes it difficult to penetrate solid samples without scratching the membrane, potentially reducing the accuracy and lifespan of the sensor. However, a spear-shaped tip on the sensor facilitates easy insertion into solid and liquid samples, making it a more versatile option.
METTLER TOLEDO offers a range of specialized pH sensors with features designed to handle the measurement of brine samples. Our InLab pH sensors with glass membranes are ideal for measuring the pH of brine samples. They are robust and allow for measurements at high pH values with minimal influence from alkaline errors.
Do you want to learn more? Download our application note for more detailed information on the pH measurement of brine samples and our specialized sensors.
The following sections provide more information about brine, its use for preservation, and the importance of pH measurement in brine samples.
What is brine?
Originally, brine was a synonym for saline water. By definition, any aqueous solution of high concentration of one or different kinds of salts is a brine. For a long time, common salt (sodium chloride) has been used to preserve food products from microbial spoilage. Preservation techniques like curing, pickling, and canning make use of salt solutions that are defined as brine. These brining practices were popular food preservation methods when refrigeration was not an option.
What happens during brining?
When a food product is brined, simple osmosis takes place wherein the salt from the brine reaches an equilibrium with the salt content of the food product. This inhibits the microbial growth by reducing the water activity of the food.
Why is measuring the pH of brine important?
Measuring the pH of brine is essential as it is widely used in food production and preservation processes. Preservation techniques like curing, pickling, and canning make use of salt solutions that are definded as brine. The use of brine is prevalent in the canned food, cheese, fish, and meat curing industries.
Do we have any guidelines from regulatory bodies concerning the ideal pH of brine?
Food acidity prevents foodborne illness caused by C. botulinum bacteria. Based on this fact, the code of federal regulations under 21 CFR part 114 requires that the canned foods industry maintain an equilibrium pH of 4.6 or below in acidic canned foods. To comply with these guidelines, it is imperative to frequently test and record the pH value of the liquid brine and of the solid food during the manufacturing and production processes.
