Bread pastry baked products The term baked products

Bread & pastry

baked products’ • The term ‘baked products’ is applied to a wide range of food products, including breads, cakes, pastries, cookies and crackers and many other products, and it can be difficult to identify a common thread linking the members of such a diverse group. The most commonly-identified link is that they all use recipes that are based on wheat flour.

• This definition, though, would need to be expanded to include baked goods such as glutenfree products, used by people with coeliac digestive disorders, or rye bread, which are still considered to be baked products even though they are based on cereals other than wheat. • However, the same leniency of definition could hardly be extended to include meringues, which contain no cereal-based material at all, let alone wheat flour, their main components being sugar and egg white. It may be more appropriate to consider that baked products are those products which are manufactured in a bakery, that is the place of manufacture defines the product rather than some ingredient, recipe or process feature.

• Baked products are foods manufactured from recipes largely based on or containing significant quantities of wheat or other cereal flours which are blended with other ingredients, are formed into distinctive shapes and undergo a heat-processing step which involves the removal of moisture in an oven located in a bakery.

• Traditional basis for classifying bread and fermented goods, cakes, pastries and biscuits. Given that baking has such a long history and so many traditions associated with it, how have the various groups of baked products come to be defined? Unlike botany or zoology there has never been an attempt to develop a specific taxonomy of baked products. In part this may be because of the long, local traditions associated with the manufacture of baked products and therefore the difficulties associated with translation from one tongue to another of the terms and descriptors used for the products and their associated baking processes.

To some extent, this nomenclature problem has persisted to the present day. For example, in English the term ‘biscuit’ is commonly used for describing a low moisture, hard-eating, sweetened, thin product with a long shelf-life, that is eaten as a snack. In the USA, however, it commonly refers to a sweetened product of intermediate moisture, commonly eaten at breakfast along with savoury foods. The UK biscuit is closer to the US cookie while the US biscuit is closer to a UK scone. To increase the confusion, the French biskuit refers to a low moisture, dry-eating, long-shelf-life, sponge-type cake with an aerated structure. The closest UK product to the French biskuit is indeed a sponge cake, though with higher moisture content.

An introduction to the methods used to characterize baked products: • Take any baked product and you will observe that it has a number of different textural and sensory attributes. Even the matrix of a loaf of bread is not as homogenous as it first appears. Starting from the outside, we would see a light - to dark-brown surface which, when fresh, is hard to the touch and has a dry and crisp eating character.

• The inside of the loaf, however, has a sharplycontrasting appearance. It is white or light brown (depending on whether white, brown orwholemeal flour has been used in its preparation) and has an expanded and cellular structure. By comparison with the crust, the crumb is soft to the touch and may well spring back after compressive forces are removed. • The sensory properties in the mouth will be dominated by softness and chewiness.

• The degree of variation depends very much on the bread recipe and the process employed, especially in the dough making, but there will almost always be a contrast between the surface and interior properties of the loaf. A range of texture and sensory variations is also experienced when base cakes, pastries and bis -cuits are examined.

Fermentation • Fermentation: means the breakdown of carbohydrate material by micro-organisms (or enzymes) under anaerobic conditions, • In common usage, the term FERMENTATION refers to both the anaerobic and aerobic breakdowns of carbohydrates and carbohydrate-like materials , to alcohols and carbon dioxide or organic acids by yeasts, bacteria, or combination of there, under anaerobic conditions.

Bread Fermentation • During Fermentation yeast undergoes anaerobic metabolism, producing Co 2 gas , which aerates the dough. • Also it imparts flavor to the baked product. • About 40% of total carbon dioxide gas produced by yeast fermentation retains in the proofed dough. • The remaining 60% is lost during punching, molding , and proofing the dough. • The increase in dough volume during baking (oven) primarily is attributed to the vaporization in ethanol, with a small amount contributed by water vaporization. • The PH –value of the dough decreases and the acids have a softening and mellowing effect on the gluten. • The temperature during fermentation is around 27°C and relative humidity should be 75 % to 80 %.

The function of yeast • It acts as a leavening agent in the dough ( Co 2 production) • It has to develop flavors ( from alcohols, esters and flavor production) • It has to develop the dough ( dough ripening).

About Yeast • Single celled, microscopic plant. • When you add sugar to yeast, it reacts to the bacteria and creates carbon dioxide. This leavens the baked product. • Water mixed with yeast MUST be between 43 and 50 degrees in order to keep the yeast alive. • Available in three forms: – Active dry (what we use) - Compressed ( very perishable) - Fast rising yeast (rises twice as fast)

Types of Yeast Commercially available 1– Yeast cream Used directly, highly perishable 2– Yeast cake Yeast cream through filtration press or vac. filter Refrigeration required, shelf life a few week Metabolically active, quick fermentation 3– Dry active yeast Home bread making, small business operation Last 6 months or longer , Require hydration, not as active S. cerevisiae, or bakers’ yeast

Factors affecting fermentation 1. Too much salt inhibits yeast activity, reducing the amount of carbon dioxide gas produced and decreasing the volume of the loaf. 2. The temperature has a great influence on the development of the yeast. Above 45 °C yeast cell are destroyed. 3. Over fermentation • Gluen streches, becomes weak and can collapse • Coarse grain & sour odor due to excess acid production • Less color in baked crust.

• Measurement of carbon dioxide (CO 2). • for measurement of Gassing Power by the Pressuremeter method to measure the gas production by baker’s yeast and with ( flour , sugar and …. ) Flour slurry used instead of dough for compatible with our instrument experiment design

Procedure 1. 2. 5 g of flour (weighed on 14% mb). 2. Mix with 20 ml of distilled water followed by 0. 075 g dry yeast, in a dry and clean 250 ml Pyrex bottle, the mixture vortex for 15 Sec. move to 30°C regulated water path , and read the pressure meter on (Sphygmomanometer 0300 mm. Hg) , and let for fermentation for 5 hr with reading the gas pressure an 1 hr intervals.

Lab 3: Methods of Bread Production • A large number of baking methods exist around the world, with each country having its own traditions and practices handed down over generations, producing a wide variety of types of bread. In practice, these methods can be classified into two main processes: (a) bulk fermentation (BF) and (b) mechanical dough development, or the Chorleywood bread process (CBP).

1 -Bulk Fermentation The major traditional bread making process is the bulk fermentation process. All the dough ingredients are mixed slowly into an even mix. The dough is left to ferment in bowls for a set period of time, usually 2– 3 hours. After mixing, the dough is a rough, dense mass which is not extensible and does not retain gas, but as the dough ferments it transforms into smooth, extensible dough with good gas retention. The dough is then divided into loafsized quantities, given final rising and baked. • Setting up a recipe for BF bread requires the adjustment of four main variables, which are all ultimately linked: 1. 2. 3. 4. Yeast quantity Fermentation Time Dough temperature Oxidizing agent

2. Mechanical dough development or (Chorleywood Bread Process) A short or no time bread making process where the dough is mixed at very high speeds and this energy is used to shear the gluten structure and allow reformation. The amount of time the dough needs to rise is reduced from 2 hours to 10 minutes due to the development during mixing. Not only does the CBP save considerable time in the baking process, which helps keep down the production costs and delivers cheaper bread, but it also produces bread which is better in respect of volume, color and keeping qualities. CBP is now by far the most common method used throughout all sectors of the bread baking industry.

Bakers’ yeast or sourdough Flat breads may be leavened (have a raising agent of yeast or sourdough) or unleavened. Sourdough is also used in flat bread fermentation. Sourdough consist of a piece of dough saved from the previous baking that is then mixed with flour, salt and water to produce bread. Sourdough fermentation can modify healthiness of cereals in a number of ways: 1. It can improve texture and palatability of whole grain, fiber-rich or gluten-free products, 2. Stabilize or increase levels of various bioactive compounds, 3. Retard starch bioavailability (low glycemic index products) and 4. Improve mineral bioavailability

Sourdough fermentation has a positive effect on bread quality because it improves bread flavor and texture and prolongs shelf life due to the formation of antifungal compounds and delays staling. Baking There needs to bake it in special ovens in high temperatures varying 350 -550 C for a quality flat bread production. Some flat bread is baked on an overheated hot plate with different shapes of dough. For example, yufka is baked on a hot plate for 15 -30 seconds. When flat bread is baked at high temperatures in a shorter time, they receive better crust characteristics.

Lab 4: Bread faults: their causes and Remedy There a number of factors which are responsible for creating faults in bread. Major factors which adversely influence the quality of bread are: • Inadequate gluten in flour • Poor diastatic activity of flour • Improper time and temperature of fermentation, proofing and baking. • Wrong methods of manipulation of dough i. e. knocking, cutting and moulding. • Inadequate cooling of bread • Improper storage of bread and • lack of knowledge about the principles of hygiene

Major faults in white bread volume: volume of the bread is the outcome of adequate conditioning of gluten and sufficient gassing power of the dough at the time of baking. A small volume of bread may be due to : 1. Tight dough 2. Little yeast and fermentation time 3. Low temp. 4. Under proofing 5. Under mixing or over mixing 6. Very high temperature during baking 7. Adding of excess of salt 8. Use of weak flour 9. Bran contamination

Excess volume can be due to : • Over fermentation • Lack of salt in formula • Excessive yeast and proofing time • Loose moulding • Lack temperature in oven or cool oven Crust color : Crust colour shall be too dark due to: • Addition of more sugar in the formula • Over baking • High oven temperature • Old dough

Leathery curst • The crust of bread should be crisp and should easily break but if the curst becomes tough and is not easily pulled, it is leathery. It is due to insufficient conditioning of gluten or if crust absorbs lot of moisture. Sticky crumb • It may due to sprout damaged wheat flour if is proved or baked in excessive humid conditions and under baked. Crumbiness of the crumb When the dough is adequately fermented , it gives elasticity to bread crumb otherwise the bread crumb will break into small fragments while slicing called crumbiness. It may be due to : 1. Tight dough 2. Excessive use of fat 3. Low salt content 4. Excessive use of mineral improvers.

Irregularity Loose molding or molding with uneven pressure result in large air pockets in the folds and causes irregularity of shape. Poor flavor and taste These can be due to 1. improper storage of raw ingredients used 2. poor quality ingredients 3. unfermented or over fermented dough Ropy bread If the dough gets contaminated with B. mesentericus , bread ropiness is caused. The spores of these bacteria are not killed by heat during baking. A sticky , gummy material which can be pulled into threads develops in the centre of the loaf 1 to 3 days after baking.

Staling of bread • If the bread is stored for a number of days , certain changes occur which cause staling of the bread. These are • Crust staling • Crumb staling

Rich Dough Defined a rich dough is generally one that is high in fat and sometimes high in eggs or sugar. Doughs that have little or no fat are often referred to as lean dough. Effects of Fat on Dough The introduction of fat into bread dough has several noticeable effects: 1. It coats and literally shortens the strands of gluten, creating what is known as the shortening effect. If the fat is a liquid, such as olive oil, this effect can create a silky texture in bread. If it is a solid, such as butter, it can create textures ranging from soft to crumbly or flaky, depending on the quantity used and how much it is worked into the dough. 2. It interferes with the bonding of gluten strands, thereby reducing dough strength and increasing dough tenderness. 3. It can add to the flavor of the dough if the fat has a noticeable taste (such as butter or olive oil), and it can affect mouth feel either pleasantly (as with butter or olive oil) or unpleasantly (as with any fat that doesn’t melt in the mouth, such as vegetable shortening).

Effects of Sugar on Dough • Sugar interferes with gluten formation in bread dough, so, with regard to dough structure, it always acts as a tenderizer. At levels of more than 12% of the flour weight, this tenderizing effect can seriously slacken the dough. At the same level there is also a noticeable slowing of the rate of fermentation and, from this point on, the rate of fermentation continues to slow as the sugar levels are increased. • If you want to include large quantities of fat or sugar in your bread dough, then you must accept the effects of these ingredients on the dough and take measures to incorporate them without seriously damaging the strength of the dough.

Adding Sugar 1. As we mentioned before, high levels of sugar can negatively affect both dough strength and fermentation activity. 2. Fermentation, on the other hand, can’t be improved by adding sugar in stages, so you must increase the level of yeast in dough to make up for the slower CO 2 production that occurs with high concentrations of sugar. It isn’t unusual to see levels of instant yeast totaling 2– 3% of fl our weight to counteract the negative effects of sugar levels greater than 12%.

Functions of Eggs: In Yeasted Doughs 1. 2. 3. 4. 5. 6. increase nutritive value, improve flavor and texture, produce color in crumb and crust, act as a binding agent to hold the ingredients together, aid in leavening, contribute to the emulsifying action due to the presence of the natural emulsifier lecithin, 7. and produce a softer crumb because of the fat and other solids. Eggs contain 73 to 75% moisture, have the natural ability to bind and retain moisture, and hence improve quality. Eggs are an important source of iron, calcium, phosphorus, vitamin A, vitamin D, thiamine, and riboflavin, and they supply all essential amino acids. The complex composition of eggs imparts numerous functional effects on baked products.

• In cake 1. Emulsifies fat: The yolk or yellow portion which is responsible for the egg's emulsifying properties from the fat and lecithin contained in them (whites do not contain fat). 2. Contributes to the structure: egg whites provide extra volume and air. Most egg replacers on the market will provide instructions for replacing whole eggs and egg whites. 3. Eggs also act as binding and leavening agents. 4. Contributes nutritive value: it provide richness, colour, protein and tenderness. In Cookies Eggs help in puffing, emulsifying the dough, and bringing the water and fat phases together to result in a creamier and smoother texture in cookies. Egg whites have a drying effect and contribute to the structure or shape. Swiss roll recipe Swiss roll is an ingenious cake. Like a lot of good things, less is more, and it the recipe requires just four everyday ingredients – caster sugar, plain flour, eggs and jam. But it’s how you use them that counts.

MUFFINS AND QUICKBREADS Muffins and quick breads are more closely related to cakes than breads, since they are chemically leavened and share the same mixing methods as cakes. The only difference is that they are less “cakey” than cakes, although these days’ bakeries often sell little cakes with the name of muffins. If it is too rich to tolerate a pat of butter, it’s not a muffin.