One of the most common measurements of food products is pH. The pH influences many qualities of food products including flavor, fermentations, texture, appearance and shelf stability. Foods are generally broken into two groups based on their pH value. These groups include acid foods which have a naturally low pH of 4.6 or below and low-acid foods that have a finished equilibrium pH values greater than pH 4.6 and a water activity greater than 0.85. The low-acid foods can be pH adjusted with an acid to lower the final pH and become an acidified food. Maintaining a lower pH will help in preventing unwanted bacteria from growing.
Food products can provide a number of challenges for the person that needs to measure pH. Food products tend to be solid, semi-solid or as a slurry with a high content of solids. All three types of samples will coat the sensitive glass membrane surface and/or clog the reference junction. The FC2023 that is supplied with the HI98161 is designed specifically for measuring pH in food. From a conic tip shape for easy penetration, open junction that resist clogging, and a Polyvinylidene fluoride (PVDF) food grade plastic body that is resistant to most chemicals and solvents, including sodium hypochlorite. It has high abrasion resistance, mechanical strength and resistance to ultraviolet and nuclear radiation. PVDF is also resistant to fungal growth. The FC2023 is an ideal general-purpose pH electrode for food products that connects to the HI98161 with a quick-connect, waterproof DIN connector, allowing for a secure, non-threaded attachment.
Besides being supplied with a unique foodcare pH electrode, the HI98161 has the Hanna’s unique CAL Check™ feature that alerts the user to potential problems during the calibration process. This is a very important for the food processor since it is likely that the probe will be coated with the solids found in the food product being measured. This coating can easily lead to errors in pH measurement. By comparing previous calibration data to the current calibration, the meter will inform the user, with display prompts, when the probe needs to be cleaned, replaced, or if the pH buffer might be contaminated. After calibration, the overall probe condition is displayed on screen as a percentage from 0 to 100% in increments of 10%. The probe condition is affected by both the offset and slope characteristics of the pH electrode, both of which can be found in the GLP data.
Pressing the “AutoHold” virtual key in measurement mode, the meter will freeze and automatically log a stable reading. An “out of calibration range” warning can be enabled that will alert the user when a reading is not within the bracket of calibrated pH values.
The log-on-demand mode allows the user to record and save up to 200 samples. The logged data, along with the associated GLP data, can then be recalled or transferred to a PC with Hanna’s HI920015 micro USB cable and HI92000 software for traceability in record keeping for specific product batches. GLP data includes date, time, calibration buffers, offset, and slope, and is directly accessible by pressing the dedicated GLP key.
A contextual help menu based on the screen that is currently being viewed can be accessed at any time by the press of a dedicated button.
The high contrast, graphic LCD screen is easy to view outdoors in bright sunlight as well as in low-lit areas with the backlight. A combination of dedicated and virtual keys allows for easy, intuitive meter operation in a choice of languages.
The compact, durable HI720161 carrying case is thermoformed to hold all necessary components for taking a field measurement, including the meter and electrode, beakers, buffer solutions and cleaning solutions.