Dairy Foods turned to Merieux Nutrisciences, a food safety and quality firm, for advice about installing an extended shelf life (ESL) line and UHT (ultra-high temperature) equipment in a dairy processing plant. Gerald Witherington and Nancy H. Eggink shared these thoughts.
Employee safety
Safety is of the utmost for all employees to be aware of when around this processing equipment. “You are dealing with a system that is pasteurizing above 275 F and washing at almost 310 F,” said Witherington.
The UHT system should be off-limits to non-processing personnel because of the process piping that carries high-heat product throughout the system. Limiting access does depend upon the design of the system, Witherington noted, because some skid-mounted units are compact enough that the hazardous area is within the confines of the skid itself.
Employee training
Make a check list for items that need to be inspected and signed off on prior to production.
Are sanitizer nozzles operational (typically these can be manually activated)? Are the nozzles spraying sanitizer in the fill area of the machine?
Make checks of the steam sterilization procedure during the pre-startup phase.
Operators must understand that these are sterile machines; that includes the interior environment of the machine.
Maintain the HEPA filters on the machine to protect the internal environment.
The nature of ESL processing
Because ESL products are in commerce for a longer period of time, any contaminant organism has a longer time to grow in the product, said Eggink. These products are also in the supply chain for a longer period of time, meaning there are more opportunities for temperature abuse.
This is only an issue if there is a contaminant organism in the product. Keep in mind that many school milk products are UHT/ESL. Children are a vulnerable population. The hazard analysis should take that into account when developing a food safety plan.
Typically, dairy processing facilities use an ATP system (adenosine triphosphate) for release testing of UHT products. This includes a pre-incubation of the product for 48 hours. Thus, dairies need a larger room for the incubation period. Also, dairy labs need a large amount of counter space to manage the size and volume of finished product samples that will be tested.
Storage needs
Because UHT/ESL products have a longer shelf life, dairies need a larger storage area to keep these samples. If a facility is co-manufacturing, they may also need to keep samples from every production run and every label, Eggink said.
Do not store or retain shelf life samples in the cooler that holds general inventory. While the temperature is controlled, there are opportunities for damage and employee consumption. The samples should be stored and controlled as laboratory samples.
Working with suppliers
Witherington said dairy processors need close relationships with the machine manufacturer, the container supplier and the chemical supplier. A dairy’s maintenance department needs to be trained by the machine manufacturer in all aspects of maintenance on the machine, including:
Normal maintenance and adjustments
Preventative maintenance issues
Sanitation training
Trouble-shooting techniques regarding all aspects of the filler operation. This includes drive system, electronics (sensors, electric eyes, pressure switches, etc.) and a full understanding of the HMI (filler control panel) and its various modes of operation.
