Governing temperature in frying
December 12, 2016
by Laurie Gorton
Not only does the frying medium conduct heat to the chip or pastry, but it also becomes part of the product.
Frying employs a unique cooking method. Not only does the frying medium conduct heat to the chip or pastry, but it also becomes part of the product. A few degrees up or down in oil temperature make huge differences in finished product quality. Many current improvements in frying technology center on process temperature control.
“Fryer advances are driven primarily by the demand for cook consistency while maintaining flexibility, food quality and food safety,” said Nathan Lee, vice-president of sales, US and Canada, PPM Technologies, Inc. “Developments at our company for fryer design and engineering are focused on oil management and accessible solutions.”
PPM Multi-Zone oil flow, a new feature, eliminates particle build-up and provides easily adjustable temperature profiles through each frying zone, he explained. This enhances oil protection to maximize oil quality and improve return on investment by reducing oil input. The company’s patented Flow Injection Side Turbulent system ensures separation of slices and efficient water evaporation. The fryer also features continuous oil filtering.
Temperature management figures into bakers’ requirements for faster changeovers and quick response times between SKUs, according to David Moline, sales and marketing manager, Moline Machinery, LLC. “You need firm control over temperature at entry through discharge,” he said.
Moline electric fryers feature four zones to manage hot and cold points. “You want specific heat control at specific points in the process, where you need it the most, and you may need split controls if you need a hotter oil at some point or for a specific product,” Mr. Moline said. “For example, cake donut batter is cold when it enters the cooking oil, placing more demand on heat control at the beginning of the process.”
Florigo Industry, a TNA company, developed opti-flow technology that employs fluid dynamics to optimize heat transfer. explained Arnaud Jansse, applications engineer, “Normally, as the oil flow increases in a fryer, so does the turbulence, which can cause the oil to spin in one place, resulting in unevenly fried potato slices and, therefore, an increase in the level of acrylamide and rejects.”
The new technology produces a more streamlined laminar flow over the full width and length of the fryer pan, he continued. “It effectively minimizes the occurrence of turbulence by removing 99% of cyclone dead spots at the beginning of the fryer,” he noted. This action prevents debris from settling and limits excess oil absorption. The method is now part of the Florigo conti-pro PC 3 potato chip fryer.
At WP Bakery Group USA, synchronized coil heating reduces temperature fluctuations in its open kettle fryers. Electrical heating coils are cycled on and off during initial heating to gently bring oil up to its set-point temperature. This temperature will drop when products enter the oil, so the system immediately releases more heat to the oil. Without this feature, the bottom of the kettle would be significantly hotter, causing sediments to burn and cutting the useful life of the oil, noted Patricia Kennedy, president, WP Bakery Group USA.
“We save energy as a result of this because the heat that is generated is only released into the fat that needs to be warmed up,” she said.