pH of Brine for Canned Food Testing
For brine of canned acid foods, the equilibrium pH value must be 4.6 or below to inhibit the growth of Clostridium botulinum, the most heat resistant of the food pathogen microorganisms.
Introduction
The anaerobic bacterium Clostridium botulinum produced in improperly canned foods has caused illness and death. The vacuum seal on cans provides an oxygen-free environment that will allow C. botulinum spores to grow and produce deadly toxin, if the canning process is not carried out properly. Fortunately, the C. botulinum spores will not grow in high-acid foods (pH ≤ 4.6). For low-acid foods (pH > 4.6), these spores that are resistant to boiling water temperature must be killed during the canning process.
The appropriate pH in the cans is obtained by the use of brines with known acid concentrations or tablets of known acid compositions that are added to cans of specified volumes. The contents of the cans must be then conveniently stirred to ensure that the pH is below 4.6 in the center of all food particles. Acids used in canning to lower the pH to 4.6 are usually citric, lactic and malic, but also glucono-delta-lactone.
The LAQUAtwin pH meter can be used by food processors or home canners to measure the pH of brine in canned foods. There are three (3) LAQUAtwin pH meter models available, namely pH 11, 22, and 33. These light, pocket-sized meters allow two to five calibration points using either NIST or USA pH buffers. The pH 33 meter has built-in temperature sensor that measures and displays temperature and automatic temperature compensation feature (ATC) that performs automatic calibration to the exact pH of the buffer at the measured temperature. Refer to the specifications of each meter model for more information.
Method
Calibrate the LAQUAtwin pH meter using pH 4.01 and 7.00 (or 6.86) buffers according to manufacturer’s instructions.
Sample Measurement
Using the pipette that comes with the meter, take an aliquot of the brine sample and place some drops into the sensor. Record the pH and temperature once stabilized. After testing each brine sample, rinse the sensor with water and blot dry with soft tissue. To obtain accurate results, a uniform temperature should be maintained for the standard buffer solutions and brine samples. The test should be made at a temperature between 20-30°C, the optimum is 25°C.
.png)
Results and Benefits
Food acidity is important in preventing botulism, a foodborne illness that comes from eating contaminated food with toxins produced by C. botulinum. This fact is used in canning acid foods. Aside from following tested recipes and proper canning methods to ensure that C. botulinum is killed and does not grow in canned food, performing accurate pH measurement using a reliable instrument is also necessary to ensure that the correct pH value of 4.6 or below is attained for food safety and regulatory compliance. The final equilibrium pH (the pH of a food product after the food acid is distributed equally throughout the product) must be checked, controlled and documented after the product has completed the thermal processing step.
References
- Sun, Da-Wen. Thermal Food Processing New Technologies and Quality Issues. 2nd ed. USA: CRC Press, 2012.
- Numer, Brian. Food Acidity and Safety. FN/Food Safety/2008-01. Utah University. August 2008.
- Pickle Bill Factsheet. Dairy and Food Inspection Division. Minnesota Department of Agriculture
LAQUAtwin: the only meters with flat sensor technology.
HORIBA’s highly-sensitive, flat sensor technology opens up new possibilities for sampling and sample types. Only a small amount of sample is required, so you can easily sample in situ without the need for beakers or other labware. Sensors are easily replaced as required.
Calibrate and measure at the touch of a button — the smiley face will tell you when the result can be read.
LAQUAtwin is fully waterproof and dustproof.
The meter and sensor are fully waterproof* and dustproof, so you can take it anywhere.
* IP67 rated. Will withstand immersion for 30 minutes at 1 m. Not suitable for underwater use.
Carry case comes as standard for handy portability.
The compact carry case contains everything you need for your measurements, including the standard solution and sampling sheets.
Matching products
HORIBA pH Handheld Tester – Ideal for Water and Environmental Analysis Precise pH measurements on-site – compact, reliable, and easy to use The Horiba LAQUAtwin pH tester is ideal for water quality testing in rivers, drinking water, and process water. With a measurement range of 0.0 to 14.0 pH and a 2-point calibration, the tester is suitable for a wide range of pH analyses. Just a single drop of sample provides quick and reliable measurement results. The tester combines electrode, display, and sample container in a robust IP67-rated housing that is dust- and waterproof. The digital display with backlight shows both pH and mV values. Features such as automatic stability detection and Auto-Hold simplify operation. With up to 400 hours of battery life, the tester is suitable for extended measurement series. Included are calibration buffer solutions (pH 4.01 & 7.00), batteries, pipette, instruction manual, and a carrying case. Handheld pH tester for fast and precise results With its wide measurement range and 2-point calibration, the Horiba LAQUAtwin pH tester is suitable for a variety of pH analyses. Even a single drop of sample is enough to obtain fast and accurate results. Its compact design makes the mobile pH tester highly user-friendly and allows on-site measurements without complex sample preparation or laboratory infrastructure. Robust, waterproof design with comprehensive features The tester integrates the electrode, display, and sample container in a robust IP67-rated housing that is dust- and waterproof. The digital backlit display clearly shows pH and mV values. Features like automatic stability detection and Auto-Hold simplify daily use. With a battery life of up to 400 hours, the tester is suitable for long measurement series. The package includes calibration buffer solutions (pH 4.01 & 7.00), batteries, pipette, instruction manual, and a practical carrying case. Typical applications of the Horiba LAQUAtwin pH Pocket Tester Aquaculture and corals Aquariums Beer, beverages, and food Heating systems Laboratories and schools Horticulture Water treatment Frequently asked questions How long is the warranty period for HORIBA pocket testers? The warranty period is two years from delivery for commercial customers. How many measurements can be taken before the sensor needs to be replaced? This varies depending on the application, use and storage of the Horiba tester. As a rule, the sensor should be replaced after one year. How long is the warranty period for replacement sensors for pocket testers? The warranty period is 12 months after delivery for commercial customers. How do you clean the pocket tester? The pocket tester can be rinsed under water. We recommend cleaning with DI water (deionised). Tissue paper is recommended for drying after cleaning. How can the pocket tester be reset to factory settings? (e.g. in the event of an incorrect measurement result) This information can be found in the operating instructions. These can be found in the download area of the shop and on the product. Is calibration necessary before each measurement? Basically, yes. Further information can be found in the operating instructions.
Mobile pH Tester with 3-Point Calibration for On-the-Go Use Horiba LAQUAtwin pH Tester – ideal for water and environmental analysis The Horiba LAQUAtwin pH Tester pH-22 is compact, robust, and designed for mobile use. With up to three calibration points and a measurement range of 0.00 to 14.00 pH, this device delivers high precision and reliability. Direct measurement with just a single drop of sample provides fast results. Features such as automatic buffer recognition, temperature compensation, and Stabil/Hold functionality make daily operation simple and convenient. Mobile precision pH tester for reliable on-site measurements The tester combines electrode, display, and sample container in a dust- and waterproof IP67 housing, making it ideal for field and laboratory applications. The digital backlit display shows pH and mV values clearly and accurately. Automatic shut-off and battery status indicators ensure convenient operation. The package includes calibration buffer solutions (pH 4.01 and 7.00), batteries, a pipette, and a quick-start guide. Why accurate pH measurement is critical – and why a handheld tester is ideal pH is a key parameter in water, environmental, and process analysis because it significantly influences chemical reactions, biological processes, and material stability. Even small deviations can substantially impact water quality, product quality, or process safety. A mobile handheld pH tester allows fast, reliable measurements directly on site. Changes can be detected immediately, and corrective actions implemented without delay. The Horiba LAQUAtwin pH-22 combines this flexibility with high measurement precision, making it ideal for field, laboratory, and routine applications. Typical applications for the Horiba LAQUAtwin pH handheld tester Aquaculture and coral monitoring Beer, beverage, and food production Heating systems Laboratories and schools Environmental analysis Water treatment Horticulture Frequently asked questions How long is the warranty period for HORIBA pocket testers? The warranty period is two years from delivery for commercial customers. How many measurements can be taken before the sensor needs to be replaced? This varies depending on the application, use and storage of the Horiba tester. As a rule, the sensor should be replaced after one year. How long is the warranty period for replacement sensors for pocket testers? The warranty period is 12 months after delivery for commercial customers. How do you clean the pocket tester? The pocket tester can be rinsed under water. We recommend cleaning with DI water (deionised). Tissue paper is recommended for drying after cleaning. How can the pocket tester be reset to factory settings? (e.g. in the event of an incorrect measurement result) This information can be found in the operating instructions. These can be found in the download area of the shop and on the product. Is calibration necessary before each measurement? Basically, yes. Further information can be found in the operating instructions.
Manufacturer Part No. 3999960124 LAQUAtwin PH-33: The world's first pocket-sized PH meter Your mobile laboratory - for use on site: Ideal for water quality testing in aquatic, drinking and process water and many other applications. HORIBA's unique compact meter integrates electrode, display and sample container to enable simple, effective on-site testing by direct measurement with a single drop. Minimum sample volume: 0.1 ml (0.05 ml with sampling sheet B) Up to 5 calibration points pH, mV and temperature display Automatic calibration Automatic buffer recognition: USA & NIST pH buffers Automatic temperature compensation Temperature calibration: 5 to 40.0 ºC Automatic stable / automatic hold measurement Automatic switch off: 30 min. Low battery indicator IP67 rating dust and waterproof Replaceable sensor 400 hours battery life: continuous operation without backlight Material: ABS epoxy Display: customised (monochrome) LCD with backlight Operating conditions: 5 to 40°C, 85% or less relative humidity Warranty: 2 years - meter, 6 months - sensor Packed in a practical carrying case Supplied with pH 4.01 & 7.00 buffers (14ml each), 2 x CR2032 batteries, dropper, instructions and quick reference guide