On-line NIR moisture measurement to control the degree of baking in biscuits and cookies Hartmut Federle Faculty Product Engineering
Contents On-line moisture measurement in baking process Baking process a new challenge Biscuit gauge Results achieved Benefits of on-line moisture measurement Summary
On-line moisture measurements in baking process Durable baked products Cookies Crispbread Biscuits Crackers Source:Werner&Pfleiderer Industrielle Backtechnik
On-line moisture measurements in baking process Key steps in cookie baking Ingredients Dough Mix Cutting or Moulding Baking Cooling NIR gauge Stacking Sandwiching Packing
Baking process - a new challenge Measurement location Ingredients Dough processing Cutting/Moulding Tunnel Oven Cooling section
Baking process a new challenge Parameter of interests Moisture measurement of single biscuit Trend information about parameter moisture Avoid burnt flavor to measure the degree of bake
Baking process - a new challenge Specifications for an online gauge Moisture determination in each biscuit Discontinuous measurement Product size small Ø 35 mm Gap between 2 biscuits > 25 mm Speed of steel belt up to 10 m/min = 167 mm/s Measurement to determine the degree of bake
Biscuit gauge degree of bake Dual component gauge BG710 Detector for degree of bake Source: NDC Infrared Engineering
Biscuit gauge degree of bake New dual component gauge measuring moisture and degree of bake Degree of bake measurement calibrates to the colorimeter L* scale (Brightness) for each product Analogue or digital outputs as with moisture Application restricted to biscuits and cookies
Biscuit gauge gating system Paired detector/emitters identify leading and trailing edge of biscuits Set-up learns thickness of thinnest product Stops data collection on belt (response speed:1.25ms) Source: NDC Infrared Engineering
Biscuit gauge gating system Due to the high speed of filter revolution we get 125 complete measurements/s. This brings us up to 60 measurements per biscuit depending on the conveyor belt speed max. 10 m/min. edge detecting sensors The data collection is frozen when the product leaves the inspection window. measuring patch steel belt
Results achieved Calibration example degree of bake In this example the correlation of y to x is r = 0.98 BG710 Degree of Bake 64 63 62 61 60 59 58 57 56 56 57 58 59 60 61 62 63 Colorimeter
Results achieved 3.5 Moisture in Biscuits BG710 gauge reading % 3.0 2.5 2.0 1.5 1.0 0.5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Moisture (Oven) %
Results achieved Moisture Profile in Freshly Baked Biscuits/Cookies Moisture Dry edges Wetter centre Moisture
Benefits of on-line moisture control Target Moisture Moisture Gauge Reading Grab #1 Grab #2 Product out of specification Grab #3 Process corrected by moisture control system Upper Limit Lower Limit Time
Summary Improved Product Quality by maintaining the correct Moisture Specification Optimum Shelf-life Trend information if the parameter stays within the tolerance band or moves beyond its limits Reduced Operator Dependency Reduced Need for Lab Testing Simultaneous outputs of moisture and degree of bake (optional) Moisture signal used for control