INTRODUCTION TO FLOUR MILLING TECHNOLOGY

• Milling


  The comminution of berries of the wheat, barley, and other coarse grain crops
• Milling


  The transformation of raw material into a primary product (flour) for secondary processing (baking, cooking, etc.)
• In many cases, milling is a very simple process, involving the use of a simple grinder to create a specific particle size distribution from the bulk raw material
• Milling for the brewing industry

  • Beverages
• Milling for the breakfast industry

  • Extrusion technology
• Actual milling process in many industries is relatively simple, technological progress has been limited to increases in efficiency and the adoption of computer control to the process to improve efficiency and quality while minimizing labor requirements
• In contrast, intermediate processes, such as those milling corn for breakfast cereal manufacture have advanced considerably as a result of advances in the most complex and predominant of the milling processes, flour milling
• Illustrations from ancient inscriptions showing grain being crushed using mortar and pestle, with the resulting material being sieved to produce material of greater purity

  Egyptian and earlier times
• Roller mills began to supplement millstones in a large scale, because of the superior flour that could be produced using them


  1870s
• French process


  The method used to produce flour today was developed during this period of fundamental change in the type of equipment employed
• Older processes


  Produced typically only 10% high quality flour from the wheat berry compared to more than 70% in roller milling plants
• Newer and more elaborate process


  Higher yields of quality flour could be produced
• White flour


  The ultimate product of flour milling
• White flour milling


  The aim is to extract a maximum amount of endosperm from the wheat berry in as pure form as possible
• Co-products of white flour

  • Outer bran layers become the co-product of the process called wheat feed
  • Embryonic part or called germ is sometimes sold for animal feed with the wheat feed produced
• Gradual reduction system


  The process of taking the whole wheat berry via a series of grinding and sieving stages producing white flour of the desired quality and yield
• Gradual reduction system


  • It has enabled the production of flours of low ash content and high yield
  • Specialty or high quality flours are produced by extracting high purity sub-products from within the process
• Flour milling process


  1. Break system

  2. Purification system

  3. Reduction system
• Break system


  • The area of the process where most endosperm separation is achieved
• Purification system


  • Has the objective to separate clean farina or coarse endosperm, from fine bran or compound particles to feed the primary reduction rolls
  • Allows the miller to maximize extraction of low ash, bright color flour
• Reduction system


  • The area where the other desirable property in flour manipulated, that is mechanical starch damage
• The result of the iterative grinding and sieving process in the three processing blocks is the cumulative release of endosperm from the wheat berry, followed by the cumulative release of flour from this material
• The operational settings depend on factors as diverse as wheat type, plant operator, customer demands, equipment supplier, geographical location, and even tradition
• flour is yellowish due to beta carotene
• as endosperm nears aleurone layer, ash content increases
• (benzoyl peroxide used for whitening)
• Hard wheat flour: prone to starch damage
• Purification Block

  Roller mills

  Roller purifiers

  Sifters
• Breaking block

  Roller mills
• Reduction block

  Roller mills

  Sifters
• Henry Simon

  perfected the gradual reduction system in the 1870s