Monday, November 13, 2017

Data Acquisition for Milk and Dairy Pasteurization

Touch Screen GX10/GX20
Yokogawa Touch Screen GX10/GX20
Reprinted with permission from Yokogawa.
Pasteurization is a process that aims to reduce and destroy the number of viable pathogens/bacteria in the product so that the unwanted pathogen/bacteria does not cause harm to human health. Pasteurization is a critical process in a wide range of products such as: milk, cheese, juice and alcohol. Food and beverage manufacturers must demonstrate and ensure that products undergoing pasteurization meet the strict requirements of international standards so that the product is deemed safe for human consumption. Significant fines and penalties may be imposed if the pasteurization process is not followed.

Depending on the product, there are specific requirements on the temperature and amount of hold time required to ensure the product is safe. There are two main types of the pasteurization process:
  1. High Temperature Short Time (HTST): Product is forced between metal plates or pipes heated on the outside by hot water and product is heated to 72 °C (161 °F) for 15 seconds 
  2. Ultra Heat Treating (UHT): Product is forced between metal plates or pipes heated on the outside by hot water and product is heated to 140 °C (284 °F) for 4 seconds 
In the United States, Pasteurized Milk Ordinance (PMO) outlines the relevant standards and regulation for the pasteurization process and is administered by the Food and Drug Administration in conjunction with U.S. Department of Health and Human Services.


Pasteurization can be conducted as a batch or a continuous process. The most common process used for fluid milk is the continuous process. The milk is pumped from the raw milk silo to a holding tank that feeds into the continuous pasteurization system. The milk continuously flows from the tank through a series of thin plates that heat up the milk to the appropriate temperature. Once the milk is heated, it is sent into a “holding tube” that is set up to make sure the milk stays at the pasteurization temperature for the appropriate time before it flows through the cooling area of the pasteurizer. The cooled milk then flows to the rest of the processing line for packaging and bottling.

If the appropriate pasteurization temperature was not maintained at the outlet of the holding tube, then a divert valve opens to pass the milk back for reprocessing.

Typically, a paperless recorder is deployed to measure the temperature of the product (hot and cold) as well as the divert valve position. The operation of the divert valve is often triggered from the paperless recorder. It is imperative to record these variables to ensure the product is processed correctly through pasteurization. Additionally, the recorded data is often used for audit and traceability requirements.


Yokogawa’s best-in-class panel mount paperless recorders are fully integrated data acquisition and display stations with secure, built-in data storage and network connectivity. Panel-mount solutions are NEMA compliant and integrate the data acquisition equipment into a control panel. Yokogawa’s paperless recorder lineup meets the rigorous industry standards such as PMO, HTST and FDA 21CFRPart11.

For more information about Yokogawa products, contact:

Power Specialties, Inc.
Raytown, MO 64133
Toll Free: (800) 432-6550
Phone: (816) 353-6550
Fax: (816) 353-1740