Technology of Baking Assoc. Prof. Marie Hrušková, PhD Assoc. Prof. Marie Hrušková, PhD 30.9.2010 VŠCHT TechPek Příhoda-engl 1
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 30.9.2010 VŠCHT TechPek Příhoda-engl 2
Technology of Baking Flour for macaroni (pasta) High protein content Gluten very taught, not too elastic Semolina flour prepared from Triticum durum 30.9.2010 VŠCHT TechPek Příhoda-engl 3
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 (%) 40 10 7 1,2 2,1 Effect: (-) charge H--bonds chain turning non-polar. (+) charge cross bonds 30.9.2010 VŠCHT TechPek Příhoda-engl 4
Flour proteins glutenin fibres of wheat (left) and rye 30.9.2010 VŠCHT TechPek Příhoda-engl 5
Carbohydrates of flour starch action of α- and β- amylase 30.9.2010 VŠCHT TechPek Příhoda-engl 6
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 30.9.2010 VŠCHT TechPek Příhoda-engl 7
Blending of ingredients Flour Water Yeast Salt Fat Sugar Eggs Milk products Additives Emulsfiers Enzymes Chemical improvers Hydrocolloids Seeds and nuts 30.9.2010 VŠCHT TechPek Příhoda-engl 8
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 30.9.2010 VŠCHT TechPek Příhoda-engl 9
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 ) 30.9.2010 VŠCHT TechPek Příhoda-engl 10
Traditonal dough mixing An example of ingredients dosing (left) and mixing head 30.9.2010 VŠCHT TechPek Příhoda-engl 11
Modern continuous dough mixer with two mixing spirals inside 30.9.2010 VŠCHT TechPek Příhoda-engl 12
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 30.9.2010 VŠCHT TechPek Příhoda-engl 13
Dividing of dough a divider for hand dividing and rounding 30.9.2010 VŠCHT TechPek Příhoda-engl 14
Dividing of dough a divider for continous dividing and rounding 30.9.2010 VŠCHT TechPek Příhoda-engl 15
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 30.9.2010 VŠCHT TechPek Příhoda-engl 16
An example of molding machine for bread 30.9.2010 VŠCHT TechPek Příhoda-engl 17
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) 30.9.2010 VŠCHT TechPek Příhoda-engl 18
Baking ovens - historical technic 30.9.2010 VŠCHT TechPek Příhoda-engl 19
Baking oven type of ovens about half of 20 century 30.9.2010 VŠCHT TechPek Příhoda-engl 20
Baking oven - currently used box oven 30.9.2010 VŠCHT TechPek Příhoda-engl 21
Baking oven currently used etage oven 30.9.2010 VŠCHT TechPek Příhoda-engl 22
Baking oven modern industrial continuous tunnel oven 30.9.2010 VŠCHT TechPek Příhoda-engl 23
Different baking temperatures during baking in oven examples of increasing and decreasing curve 30.9.2010 VŠCHT TechPek Příhoda-engl 24
Temperature of the bread surface Tem p erature C 180 160 140 120 100 80 60 40 20 0 0 10 20 30 40 50 60 Time of baking (min) 30.9.2010 VŠCHT TechPek Příhoda-engl 25
Temperatures in the middle of bread loaf during baking 100 90 Temperature ( C) 80 70 60 50 40 0 10 20 30 40 50 60 Baking time (min) 30.9.2010 VŠCHT TechPek Příhoda-engl 26
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 30.9.2010 VŠCHT TechPek Příhoda-engl 27
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 30.9.2010 VŠCHT TechPek Příhoda-engl 28
Spiral cooler in modern industrial bakery 30.9.2010 VŠCHT TechPek Příhoda-engl 29
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 30.9.2010 VŠCHT TechPek Příhoda-engl 30
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) 30.9.2010 VŠCHT TechPek Příhoda-engl 31