HACCP – analysis of dairy products – Part 2: Yogurt

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Fermentation is a process that leads to biochemical changes in organic components by the action of enzymes of microorganisms, usually without oxygen, with the release of energy. Before fermentation the milk is treated and processed (selection and processing of milk, standardization of milk, homogenization of milk, heat treatment). Through all steps the temperature must be closely monitored. In fermented dairy products, milk (sugars in milk) ferments due to the presence of various lactic acid bacteria.

Milk inoculation is one of the critical points in the production of fermented dairy products. In this process, the selected microbial culture is added, and in the whole process, the optimal temperature is very important in order to start the fermentation process.

Incubation or fermentation will depend on the temperature and type of microbial culture, and it is stopped after coagulum formation at pH = 4.6. Fermentation will be stopped by cooling in two phases (first phase 15 to 20 ° C; final cooling < 5 ° C).

Portable Yogurt pH Meter - HI99164

The Hanna Instruments HI99164 is a durable, waterproof, and portable Foodcare pH and temperature meter designed specifically for yogurt analysis. Automatic calibration is performed at one or two points with two sets of buffers. All calibration and measurement readings are automatically compensated for temperature variations.

The HI99164 uses the FC2133 glass body, amplified pH electrode that offers numerous features that improve pH testing for yogurt producers. The split-level LCD displays both pH and temperature readings, along with indicators for reading stability, battery percentage, and calibration instructions.

The HI99164 uses the FC2133 amplified pH electrode with glass body. The probe’s conical sensing bulb ensures stable calibration and measurement in semi-solids and emulsions like yogurt.

Clogging of the reference junction is a common challenge faced by yogurt producers as the milk solids and proteins can easily build up on the electrode. The open junction design of the FC2133 utilizes a viscolene reference electrolyte that comes into direct contact with the yogurt sample.

Professional Portable Yogurt pH Meter - HI98164

The HI98164 is a rugged, waterproof, Foodcare portable pH meter that measures pH and temperature using the specialized FC2133 yogurt pH electrode. This professional, waterproof meter complies with IP67 standards. The HI98164 is supplied with all necessary accessories to perform a pH/temperature measurement packaged into a durable thermoformed carrying case that holds the meters, probes and calibration buffers securely in place.

The FC2133 that is supplied with the HI98164 is designed specifically for measuring pH in yogurt. From a conic tip shape for easy penetration to an open junction that resist clogging; the FC2133 is an ideal general-purpose pH electrode for yogurt products.

The FC2133 amplified pH electrode is a specialized probe that offers numerous features that improve pH testing for yogurt producers. An integrated temperature sensor allows for temperature compensated pH measurements without the need for a separate temperature probe.

The log-on-demand mode allows the user to record and save up to 200 samples that 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.

Temperature Datalogger - HI148


From storage to shipping, it’s important to monitor the temperature of your products to ensure that they are being stored in optimal conditions. Quick to setup, simple to use, the HI148 is a datalogger that is ideal for monitoring and recording temperature in applications such as food processing, transportation, museums, and horticulture.

The HI148 is housed in a rugged waterproof ABS casing with an IP67 rating which protects against the ingress of dust and submersion in water at a depth of 1 meter for up to 30 minutes.

The HI148 temperature dataloggers are available in four different models. Models are available with one or two channels with a combination of internal and/or external sensors. Loggers with an external temperature sensor feature a stainless steel probe on a 1 m (3.3’) flexible silicone cable.

All dataloggers can be programmed and transfer of logged data using a USB-C cable and the HI92148 PC software.

Data Retrieval and Analysis

The thermologgers feature extensive memory capacity: 16,000 samples for 1-channel models and 8,000 samples/channel for 2-channel models. Logged data is displayed as both a table and a graphical representation in the HI92148 software. The graphical representation can be saved as an image file, while the data can also be exported as a spreadsheet for further data analysis.

HALO PVDF Body Foodcare pH Electrode with Bluetooth® - FC2022

The FC2022 HALO is a Bluetooth Smart (Bluetooth 4.0) Foodcare pH and temperature electrode composed of chemically resistant PVDF material.

This electrode has a unique open junction design in which there is a viscolene (hard gel) electrolyte layer that is free of silver chloride (AgCl) between the sample to be measured and the internal reference cell. The open junction design resists clogging and the probe’s conical tip makes it ideal for pH measurements in food products including dairy, dough, ground meats and other semi-solid food samples.

All readings are transmitted directly to the HI2202 edgeblu or a compatible Apple or Android device running the Hanna Lab App.

One Press Connect

Easily connect to the Hanna Lab App at the press of a button via Bluetooth wireless technology.

The FC2022 is revolutionary pH electrode that incorporates Bluetooth Smart (Bluetooth 4.0) wireless technology with an application specific design. This electrode has many features that makes it ideal for measuring food related products. The FC2022 is suitable to use with samples that measure from 0 to 60°C.

The conical shaped tip design allows for penetration into solids, semi solids, and emulsions for the direct measurement of pH in food products including meat, cheese, yogurt, and milk.

HI700641P Cleaning & Disinfection Solution for Dairy Products (25 x 20 mL Sachets)

The HI700641P is a highly effective cleaning and disinfection solution that is specially formulated for use with pH electrodes that become coated with dairy deposits including milk, cheese, yogurt and ice cream. Electrodes can become dirty from use and will produce inaccurate results even as they read correctly in a pH buffer. Hanna’s cleaning solutions eliminate impurities and residues that are left on the electrode surface after taking measurements of a dairy product. Hanna suggests cleaning the bulb and junction of your electrode on a regular basis to ensure that the probe is always clean and prevent any clogging of the junction.

Author: Tajana Frančić, mag.nutr.

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