Technology of Baking

Transcription

1 Technology of Baking Assoc. Prof. Marie Hrušková, PhD Assoc. Prof. Marie Hrušková, PhD VŠCHT TechPek Příhoda-engl 1

2 Technology of Baking Flour main raw material for cereal food For yeast leavened products Wheat flour with sufficiently high protein content (11 14 % depending on country) With good quality of gluten (rigidity and elasticity) strong flour from Triticum aestivum Rye flour without damaged starch and proper activity of α- amylase For cookies and wafers Wheat flour with lower protein, not so rigid gluten weak flours from Triticum aestivum VŠCHT TechPek Příhoda-engl 2

3 Technology of Baking Flour for macaroni (pasta) High protein content Gluten very taught, not too elastic Semolina flour prepared from Triticum durum VŠCHT TechPek Příhoda-engl 3

4 Flour main componets proteins content and a role of important aminoacids OH NH 2 O H H? C=O C=O NH 2 C -C-N CH 2 CH3 CH3 CH 2 CH2 CH 2 CH 2 CH 2 CH2 CH 2 CH 2 CH 2 CH 2 S CH 2 C -C-N C-C-N C CH 2 CH 2 S??? N C-C-N O H H O H H O? CH 2 CH 2 O H H C-C-N C-C-N?? O H H O H H GLU GLUNH 2 PRO LEU LYS CYS (%) ,2 2,1 Effect: (-) charge H--bonds chain turning non-polar. (+) charge cross bonds VŠCHT TechPek Příhoda-engl 4

5 Flour proteins glutenin fibres of wheat (left) and rye VŠCHT TechPek Příhoda-engl 5

6 Carbohydrates of flour starch action of α- and β- amylase VŠCHT TechPek Příhoda-engl 6

7 Main steps of fermented dough processing Steps of baking technology: Blending ingredients Dough mixing (kneading) Dough bulk fermentation (rising) Dough dividing and moulding Shaping Final proofing Baking Baked product: Cooling (cutting, wraping) (filling, coating) Expediton VŠCHT TechPek Příhoda-engl 7

8 Blending of ingredients Flour Water Yeast Salt Fat Sugar Eggs Milk products Additives Emulsfiers Enzymes Chemical improvers Hydrocolloids Seeds and nuts VŠCHT TechPek Příhoda-engl 8

9 Two traditional ways of dough preparation: Straight: flour, water, yeast etc. mixed all together dough Indirect (sponge and dough): Flour (part), water, yeast mixed preferment + flour, sugar, fat etc. dough VŠCHT TechPek Příhoda-engl 9

10 Dough mixing and kneading Importance of development protein (wheat) or protein-pentosans (rye) structure of dough An example of dough development from weak and strong flour (consistency vs mixing time ) VŠCHT TechPek Příhoda-engl 10

11 Traditonal dough mixing An example of ingredients dosing (left) and mixing head VŠCHT TechPek Příhoda-engl 11

12 Modern continuous dough mixer with two mixing spirals inside VŠCHT TechPek Příhoda-engl 12

13 Bulk fermentation Traditionally long time process Currently considerably shortened Main source of aromatic and taste effective compounds (ethanol and/or lactic fermentations products) Production of gas (carbon dioxide) in order to form dough as a foam for future crumb VŠCHT TechPek Příhoda-engl 13

14 Dividing of dough a divider for hand dividing and rounding VŠCHT TechPek Příhoda-engl 14

15 Dividing of dough a divider for continous dividing and rounding VŠCHT TechPek Příhoda-engl 15

16 Dough moulding and shaping Importance of molding or re-mixing Sometimes between moulding and shaping intermediate proofing Shaping in most of bakeries two principes: Cutting the shape Rolling dough plate Rarely hand shaping regional bread VŠCHT TechPek Příhoda-engl 16

17 An example of molding machine for bread VŠCHT TechPek Příhoda-engl 17

18 Baking operation Processes in the oven: Intensive heating from the beginning Vapor incorporation to the oven in order to: Add some condensation heat to dough surface Help to form gelatinized starch for crust formation Relatively slow heat flow inside the loaf consequently fermentation can continue quite a long time Formation of aromatic and taste-active compounds in the crust (reaction of reducing sugars and amino acids) VŠCHT TechPek Příhoda-engl 18

19 Baking ovens - historical technic VŠCHT TechPek Příhoda-engl 19

20 Baking oven type of ovens about half of 20 century VŠCHT TechPek Příhoda-engl 20

21 Baking oven - currently used box oven VŠCHT TechPek Příhoda-engl 21

22 Baking oven currently used etage oven VŠCHT TechPek Příhoda-engl 22

23 Baking oven modern industrial continuous tunnel oven VŠCHT TechPek Příhoda-engl 23

24 Different baking temperatures during baking in oven examples of increasing and decreasing curve VŠCHT TechPek Příhoda-engl 24

25 Temperature of the bread surface Tem p erature C Time of baking (min) VŠCHT TechPek Příhoda-engl 25

26 Temperatures in the middle of bread loaf during baking Temperature ( C) Baking time (min) VŠCHT TechPek Příhoda-engl 26

27 Different structures of wheat and rye dough Wheat flour: Mixing: Gluten network swelling and formation of continuous 3- dimensional network Necessary effect of oxidation (bread) Less oxidation and no intensive mixing (cookies and wafers) Rye flour : Mixing: Swelling of gluten and pentosans No continuous network of protein Cross binding of protein and pentosans macromolecules network formation - not so rigid VŠCHT TechPek Příhoda-engl 27

28 Bread cooling Very slow cooling of the middle part of loaf Consequently very soft crumb very careful handling necessary Start of staling process quality changes Difference of bread type VŠCHT TechPek Příhoda-engl 28

29 Spiral cooler in modern industrial bakery VŠCHT TechPek Příhoda-engl 29

30 Bread staling changes of starch structure Staling mainly due to retrogradation of starch Retrogradation (recrystallisation) turning back to well organized crystalline structure of amylose and amylopectine Reversible process can be disorganized by re-heating, but softness of crumb does not refresh fully VŠCHT TechPek Příhoda-engl 30

31 Cereal products in Czech republic Wheat, wheat rye and rye bread (90% of deffined flour standard quality) Ban types (different shape and weight, without and with filling) Fine cereal product (cakes, croissants) Pastry and snack on cereals basic Pasta and maccaroni (different shape dry and fresh stage) VŠCHT TechPek Příhoda-engl 31