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1. Dry Milling of Wheat Cereal technology

2. Group 10 Members Javeria Aslam 19 Aiman Shafique 22 Aliya Ilyas 56 Rehan Ahmed 48 Submitted to: Dr. Dur-e-Shahwar

3. Presented by Javeria Aslam

4. Milling "Milling is the method of transforming the whole grain into the flour for consumption or conversion into consumable product” Dry milling: "Dry milling is the usual mean of separating the endosperm from the whole grain for crushing into fine powder, mainly for wheat and maize.“ Dry Milling of Wheat : - Wheat is milled to convert wheat grain to more digestible form, they are milled to flour. Flour is of two types. Internationally flour is a substance from which "bran" and "germ" has removed but in Pakistan two terminologies "Atta" and "Maida".

5. Nutritive losses During milling Milling of grains results in major losses (in descending order) of Thiamine Biotin Vitamin B 6 F olic acid, riboflavin, niacin, and pantothenic acid; T here are also substantial losses of calcium, iron, and magnesium

6. Wheat milling steps Carried out by dry milling; Steps involved in wheat milling are: Cleaning Tempering and conditioning Roller milling Quality Testing and Packaging

7. Cleaning Wheat arriving in mill contain foreign matter It includes dust, dirt, seeds of other crops, straw and pieces of metals These impurities decrease milling efficiency Cleaning is required to increase milling efficiency

8. Cleaning Methods Cleaning methods based upon different principles O Impurities are removed on the basis of following characteristics : Magnetic properties Size and dimension Shape Specific gravity Behavior in air current

9. Equipments Cleaning Magnetic Separator •The wheat first passes by a magnet that removes iron and steel particles. Separator •Vibrating screens remove bits of wood and straw and almost
anything too big and too small to be wheat. Entolitre De-Stoner Using gravity, the machine separates the heavy
material from the light to remove stones that may be
the same size as wheat kernels Aspirator Disc Separator Scourer

10. Presented by Aiman Shafique

11. Tempering Tempering Addition of water to optimum level and allow the grain to stand for some time to equilibrate moisture contents Objectives To toughen the bran To soften the endosperm There are different requirements for optimum water contents and duration “Harder wheat require more water and time for tempering” “Softer wheat require less water and time for tempering”

12. Conditioning Tempering in conjunction with heat treatment Commonly used by millers To increase the rate of water penetration wheat To modify wheat physiochemical characteristics Types 1-Heat Conditioning 2-Vacuum conditioning

13. Types of Conditioning Heat conditioning During conditioning wet wheat is heated by direct application of steam or through radiators at <55oc Then wheat is dried to milling moisture Vacuum conditioning Grain is conditioned at 35oC Then temperature is reduced to 25oC within vacuum treatment stages

14. Presented by Aliya Ilyas

15. Roller Milling Gradual reduction system comprising of break roll and reduction roll systems A pair of rolls accomplishes milling The pair of rolls rotates in opposite direction Difference in speed of rolls is called differential Fast roll rotates 2.5 times faster than the slower The point at which these rolls approach each other is known as nip

16. Break Roll System Objectives are Tear the kernel open Flake the bran Produce mostly middlings Produce a minimum flour 4-5 pairs of rolls Surfaces of rolls are corrugated ❑After passing through pair of rolls the grain goes through sifter ❑If it is moving back and forth it is known as simple sifter and if moving in plenary motion then plane sifter

17. Reduction roll system Reduction roll system 8-16 pairs of rolls Differential is 1.5:1 After passing through each pair of roll, material passes through sifter and purifier Different fractions obtained in reduction system Farina From common wheat Semolina From durum wheat

18. Presented by Rehan Ahmed

19. Quality Testing Parameters that are used to determine flour quality include:  protein content, wet gluten content, ash content as indicator of extraction rate, moisture level, enzymatic activity, particle size distribution These are determined by alveograph ( measures the resistance of a bubble of dough to expansion) and amylograph ( The starch properties of flour are measured by the amylograph)

20. Packaging The wheat flour ( atta ) stored in conventional packaging materials i.e.  jute (gunny), cloth, woven polyethylene threads bags  which were in contact with air deteriorated more quickly than the wheat flour stored in air tight polyethylene acetate bags containing free oxygen absorber (FOA)  The color, taste, texture, flavor, acidity, organoleptic evaluation, insect and bacterial count remained acceptable for two months in polyethylene-acetate coated impermeable bags

21. Issues In Wheat milling Good quality protein for baking Gluten strength Gluten content Milling – high yields/low ash Variety and environment Hard and soft wheats blended Insects in wheat Blending to meet flour specifications