Liquid eggs are a common resource in the restaurant and foodservice industry, offering speed and ease-of-use in a high-pressure environment. But all too often, for companies supplying liquid eggs, pasteurization resulting in unwanted coagulation can slow the production process. JBT’s Sterideal® Ohmic Heat Exchanger for Liquid Eggs offers a solution: precise heating for effective pasteurization which avoids coagulation.
Typically available in flexible, plastic pouches ranging anywhere from five litres up to one tonne, liquid eggs are sold into the restaurant and catering industry worldwide, as well as via grocery retail in northern Europe and North America. But the products apparent convenience belies the considerable hoops processors have had to traditionally jump through to deliver a viable product.
All too susceptible to coagulation during pasteurization, unwanted cooked egg can clog up tubes and piping, effectively – and frequently – shutting down processing lines for hours at a time as cleaning takes place.
The Ohmic solution
“These factories typically have to do CIP three times every day, so they lose a lot of time in cleaning as well as chemicals, electricity and steam,” explains JBT’s R&D Manager, Antonio Aldini. “So the key is having a technology that reduces cleaning frequency; Ohmic is this technology.”
The Sterideal Ohmic Heat Exchanger applies heat directly to the product, rather than replying on over-heated water or steam, removing the presence of a hot surface in the heat exchanger. With the Ohmic system, the customer can achieve a consistent temperature throughout the product, meaning there is no danger of partial coagulation due to inconsistent heat being applied.
The Ohmic solution also enables customers to extend the processing time by up to 14 hours, triplicating the processing time and drastically cutting cleaning costs. This means over the course of a year, much more product can be delivered than through a conventional system.
“Liquid eggs are a difficult product to handle because they change into the solid phase very quickly,” says Aldini. “If you cook eggs at home, you quickly get scrambled eggs – and nobody wants scrambled eggs in the pasteurizer tubes otherwise the system gets clogged up in two minutes. On the one hand, if you want to kill microbes you have to increase the temperature as much as possible, arriving very close to the coagulation temperature of the product. On the other, if you exceed the temperature, you clog the system and this happens very frequently in standard systems.”
Using a conventional pasteurizer, liquid eggs are treated at 67-68C for 2-3 minutes to kill harmful pathogens, such as salmonella, e-coli and listeria. However, by staying very close to the coagulation temperature, factories that pasteurize liquid eggs typically have to shut down 4-6 times per day for cleaning. JBT’s Ohmic technology enables liquid egg processors to keep running for extended periods of time, delivering a more effective and efficient product throughput as a result.