Thermal Profiling for Baking
How is a Thermal Profiling Used in Baking?
Thermal profiling is a baking process for optimization and control. Baking involves many stages such as proofing, baking and freezing operations. This tool allows bakers to read and analyze the change in temperature within a product while it goes through these stages.
A thermal profile helps ensure food safety and regulatory compliance for FSMA. It also helps improve product texture, quality and shelf life by monitoring things like:
- Yeast kill
- Bake out zone
- Product temperature arrival
- Color development
How does it work?
Thermal profiling measures key variables involved in thermal processing of foods and bakery products. It measures things such as:
- Internal product temperature over process time is done at one or more points of interest with sensors, and graphical plotting of temperature-time curve.1
- Convective and radiant heat fluxes used to bake the products (Btu/hr·ft2 or W/m2).1
- Total heat absorbed by the product during total bake time (Btu/ft2 or Joules/m2).
- Air velocity in convection ovens (m/s or fpm) and oven (air) temperature (°C/°F).
- Oven humidity as humidity mass ratio in lb water/lb dry air (kg water/kg dry air).
The fundamental principle of thermal profiling lies in the fact that physical, microbiological and chemical changes in the product during thermal processing occur as a function of internal temperature. Taking the baking step as example, dough enters the oven at normal proofing temperature of 35°C (96°F) and exits as bread at 93°C ( 200°F).
How does thermal profiling work for cake and batter products? Find out in our free technical paper here!
Changes taking place during baking encompass 4 major points:2,3
- Yeast kill or deactivation: yeast cells in the dough are inactivated at 132°F/56°C. This happens after the product has passed the oven spring stage, the maximum expansion from yeast activity while dough matrix is still stretchable. Ensuring complete yeast kill should take 45–55% of total bake time.
- Critical change zone: the transition from a viscoelastic dough to a firm, drier and porous or sponge structure.
- Wheat starch gelatinization: starch granules gelatinization onset is at 65°C (150°F) and is concluded at 82°C (180°F). This process should be completed...