Ken Quail,

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Strategies to Replace Flour Chlorination for the
Production of High Ratio Cake Flours

• Ken Quail,
• Kirsty Germaine,
• Chuck Walker

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Flour Chlorination

• First recognised in the 1930s.
• Allowed sugar levels up to 140 by flour weight.
• Increased batter viscosity
• greater foam strength
• better batter stability
• Increased cake volume
• Increased crumb strength and resilience

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Chlorinated
Unchlorinated
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Why Remove Chlorine?

• Chlorine gas is a dangerous chemical with OHS
  concerns
• Consumer perception over treatment of flour with
  chlorine
• Already banned in most European countries the
  UK
• No current action in Australia

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Objective

• To find an effective, cost efficient strategy to
  replace flour chlorination as a treatment for
  Australian cake flours

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Published Strategies

• Heat treatment
• wheat
• flour
• Acetylation
• Recipe modification

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Project Strategy

• Evaluate chlorinated flours to establish key
  features and provide a benchmark
• use as a guide for modifications
• Apply published methods
• seek to improve
• Develop new methods if required

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Benchmarking
pH

• Twelve pairs of commercial flours before and
  after chlorination
• Consistent pH mean 0f 4.5

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Bleaching
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Ash and Starch damage
Flour ash
Starch damage
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Extensograph
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Cakes
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Starch modification

• The RVA pattern became an important measure of
  flour quality and a guide for modification

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Flour properties

• Changes
• pH
• bleaching
• starch gelatinisation
• proteins

• Targets
• low ash
• low starch damage
• low particle size

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Research Streams

• Three main research streams
• Effect of flour quality/variety
• Ingredient Addition
• Flour Treatment

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Flour Quality

• Low protein, ash and starch damage
• Fine particle size
• High starch swelling

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Ingredient Action

• Emulsifiers
• Gums/Starches
• Egg Types/Powders
• Modified Milk Powders
• Enzymes
• Sugar Types
• Wheat starch guar gum were the most effective
  ingredient combination.

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Flour Treatment

• Oxidising/Reducing Agents
• pH variations
• Ozone
• Pressurised CO2 02 treatment
• Heat Treatment of starch flour
• High capital cost
• Batch process
• Costly
• Pre-dried flour

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Fluidised Heat Treatment

• Initial heat treatment work used radiant heat of
  170C for 30min
• Optimal flour temperatures ranged from 125-135C.
• The fluidised system was created to optimise the
  surface area of air to flour with the aim of
  decreasing the required flour treatment time.

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Fluidised Heat Treatment

• Initial Fluidised testing used
• Dried flour (4 moisture)
• Fine particle sized flour
• Set Air Temperatures 210-270C
• Times of 6-14 minutes
• Flours re-humidified before baking
• Achieved cake scores which were 90 of
  chlorinated control

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Initial Flour Moisture

• Traditional heat treatment methods require a
  drying step to prevent balling-up of flour.
• Was pre-drying required before fluidised heat
  treatment.
• Trials conducted across of range of flour
  moisture from 4 to 13

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90 Control Score
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Treatment Temperature

• To determine the maximum air temperature which
  could be used in the fluidised system before
  causing flour browning.
• Maximum Set Temperature?
• Currently gt300C
• Time 1.5min

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Particle Size

• Previous air classification study indicated that
  flours with a fine particle size performed better
  with heat treatment.
• Pin-milled heat treated the best performance.
• Pin-milled flour achieved a 13 improvement in
  cake score compared to the non-pin-milled flour.

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Standard vs Fluidised

• Pin-milled flour was heat treated using
• (a) Standard Heat
• pre-dried flour
• 170C set temp, 30 minutes
• (b) Fluidised Heat
• non-dried flour
• 310C set temp, 2 minutes
• Results indicated that both methods produced
  cakes of equivalent quality and RVA properties.

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Effect on Starch Properties
Fluidised Heated Flour (2 min)
Chlorinated Flour
Standard Heated Flour(30 min)
Unchlorinated Flour
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Conclusions

• Highest cake scores were achieved with
• Low protein
• Low ash
• High starch swelling volume
• Fine particle size
• Heat treatment
• Good formulation balance

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Conclusions contd

• Fluidised heat treatment using high
  temperature/short times produces cakes of
  equivalent quality
• Confirmed by independent cake assessment (Camden
  Chorleywood)
• Pre-drying of flour is not required with the
  fluidised system
• RVA Analysis can be used to measure the
  effectiveness of flour heat treatment

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Acknowledgements

• Thank you to Value Added Wheat CRC and GRDC for
  the principal funding
• Thank you also to BRI Research and The New
  Zealand Flour Millers Association
• Thank you for your flour samples
• Prof Chuck Walker and Kirsty Germaine