Weigher-Mixer Functions and Diverse Types of Mixers and Mixing-Regimes

  • Charles A. Stear


Efficient production begins with raw material intake and preparation, and most of these materials are biologically active, and therefore are prone to deterioration with time. This can be due to microorganisms, as a result of water content/water-activity or chemical oxidation resulting in rancidity. However, in the case of the most important raw material, flour, a definite storage-period is essential for the biochemical ripening-process to take place. This demands from the technological viewpoint, that at all times enough mature flour is available for processing. In this connection, the important parameters of the flour are: gluten quantity and quality, water content, temperature, and colour/brightness. In the case of sack-storage, the maturity of flour takes about 4–5 weeks, whereas in the case of bulk-transport and pneumatic-handling, this is reduced to 10–12 days. This is brought about by the process of aeration, both in the external silos, during transport of the flour from external silos to the daily-silos within the bakery, and by passage through mixing-worms and sieve machines (Figs 37 and 38). Another important function of the external silos is the maintenance or adjustment of the moisture between 14% and 15%, which demands a storage-temperature of 20°C and a relative humidity of 60% to 65%, depending on the properties of the flour on delivery. This fundamental procedure of flour-storage and preparation by oxygenation is very important for its baking performance, and it also eliminates storing, stacking, lifting, moving and emptying of the bags and boxes of raw materials in the bakery.


Bread Quality Dough Development Potassium Bromate Minor Ingredient Flour Weight 
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Copyright information

© Elsevier Science Publishers Ltd 1990

Authors and Affiliations

  • Charles A. Stear
    • 1
  1. 1.Salcombe, DevonUK

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