Analyzing Baking’s Impact on Flavors
By Ann Przybyla Wilkes
SFA V.P. of Communications
During the last 40 years, the science of baking has gone through a dramatic transformation. Back then, bakers thought of ovens as black boxes where heat versus time are the only variables. Today the industry has a better understanding of the complex chemical changes that take place during baking. Numerous flavor and aroma compounds are formed during process—often through complex reaction involving several steps.
One industry supplier that has been on the forefront of analyzing and applying the extensive data that has been collected over this time period is E. Terry Groff, president and CEO of Robesonia, Pa.-based Reading Bakery Systems.
“Chemical changes that take place during the baking process are among the most complex and fascinating of food reactions,” explains Groff. He added that we are now beginning to understand why small variations in oven construction can have a major impact in the quality of finished baked products.
Types of Heat
Heat is transferred in three ways: conduction, convection and radiation. Conduction occurs on a microscopic level as hot, rapidly moving or vibrating atoms and molecules interact with surrounding atoms and molecules and, thereby, transfer some of their energy or heat.
Heat transfer through convection occurs by the movement of hot or cold portions of fluid.
Finally, heat transfer through radiation results from the movement of charged particles (protons and electrons) emitting electromagnetic radiation. Radiation can occur as energy is carried away from the surface of an object or as the surface is bombarded by radiation from its surroundings. A transfer of energy occurs from higher to lower temperature.
Baking uses all three types of heat transfer, but the proportion and rate can vary. Brick ceiling ovens have a large radiant component, which affects flavor, Groff says. Through the use of flavor chromatography, he says, bakers can determine what compounds are developed due to radiation and other forms of heat transfer. This is providing a better understanding of what happens in ovens.
One of the advances over the last few years has been the development of a method to measure the humidity in ovens. Previously, only the humidity in a particular point in an oven could be measured using a probe. This is an important step in understanding what is occurring since water vapor is one of the major components of baking reactions.
Other research currently underway involves extending the shelf-life of baked products simply by changing how heat is applied. The way heat is applied, and the types of ingredients added, also can slow the glycemic index of baked products, according to other current research.
History of Innovation
E. I. Groff founded Reading Pretzel Machinery in 1947. At that time, the company was an entrepreneurial business that manufactured pretzel-processing equipment. An inventor, E.I. Groff patented the first, commercially successful automatic Pretzel Twisting Machine. E. Terry Groff joined his father in the business in 1974.
Terry Groff became president and chief executive officer in 1978.  Since then, Reading Pretzel Machinery Corp. has grown to become a leader in high-speed, automatic, pretzel production machinery. By 1997, 85% of all U.S. manufactured pretzels having a sales value in excess of $1 billion were manufactured on Reading equipment. The company has more than 200 pretzel line installations and accounts for approximately 73% of installed capacity worldwide.
In 1999, the company’s name was changed to Reading Bakery Systems to fully serve the baked snack, pet treat, biscuit, and cookie and cracker industries. In 2001, Reading Bakery Systems merged with The Thomas L. Green Co. T.L. Green has been a leader in the biscuit and cracker industry for more than 110 years and has installed more 500 production lines worldwide.
Editor’s Note: Terry Groff will be speaking on baking technology at SFA’s 2005 Pretzel & Baked Snacks Seminar on April 7 at The Penn Stater Conference Center Hotel, State College, Pa. He will present information on heat flux, humidity, time and temperature interaction, and how to control these variables to create optimum taste and texture in baked products.