Sugars and syrups 5.1 Types of crystalline sugars 51.1 Sucrose,‘ sugar Sucrose is a medium sized molecule known as a dissacharide (composed of a unit of dextrose plus a unit of fructose). It is derived from sugar cane or sugar beet which has been refined and crystallised from a concentrated solution. The term sugar is commonly used to efer to sucrose. It is by far the most commonly used type of sugar in the biscuit industry. White sucrose is available in various particle sizes, for example granulated, castor and icing. The smaller the crystal size the more luickly the sugar dissolves either in a dough mix or in the mouth Brown sugars are either partially refined sucrose, so still have syrup over their crystals, or are manufactured from white sugar by adding syrup to it. Commonly used brown sugars are demarara(with large rystal size), muscavado and soft pieces(various names are used and these sugars usually have small crystal size). London demarara is an example of a manufactured brown sugar where syrup has been added to white crystals. All brown sugars are sticky and tend to form hard lumps on storage especially after the bag is opened and exposed to the air 5.1.2 Lower sugars Lower sugars have smaller molecules than sucrose. They are mostly known as monosaccharides(e.g. one unit of dextrose or fructose) with reducing properties in chemical reactions(described later in relation to the maillard reaction in Section 5.4.6). They are normally derived from sucrose or from a starch(which has very large molecules made up of multiple units of dextrose) by a process which splits the molecules into individual units. This process is called hydrolysis The most co er sugar is de
5 Sugars and syrups 5.1 Types of crystalline sugars 5.1.1 Sucrose, ‘sugar’ Sucrose is a medium sized molecule, known as a dissacharide (composed of a unit of dextrose plus a unit of fructose). It is derived from sugar cane or sugar beet which has been refined and crystallised from a concentrated solution. The term sugar is commonly used to refer to sucrose. It is by far the most commonly used type of sugar in the biscuit industry. White sucrose is available in various particle sizes, for example granulated, castor and icing. The smaller the crystal size the more quickly the sugar dissolves either in a dough mix or in the mouth. Brown sugars are either partially refined sucrose, so still have syrup over their crystals, or are manufactured from white sugar by adding syrup to it. Commonly used brown sugars are demarara (with large crystal size), muscavado and soft pieces (various names are used and these sugars usually have small crystal size). London demarara is an example of a manufactured brown sugar where syrup has been added to white crystals. All brown sugars are sticky and tend to form hard lumps on storage especially after the bag is opened and exposed to the air. 5.1.2 Lower sugars Lower sugars have smaller molecules than sucrose. They are mostly known as monosaccharides (e.g. one unit of dextrose or fructose) with reducing properties in chemical reactions (described later in relation to the Maillard reaction in Section 5.4.6). They are normally derived from sucrose or from a starch (which has very large molecules made up of multiple units of dextrose) by a process which splits the molecules into individual units. This process is called hydrolysis. The most commonly used lower sugar is dextrose (dextrose 29
0 Biscuit,c。。 kie and cracker ower sugar is fructose which is similar to dextrose but is much sweeter. (Fructose is a sugar that can be eaten safely by persons suffering from diabetes. Maltodextrin is a mixture of partially hydrolysed molecules of starch. It has a low sweetness but is readily soluble. These lower sugars are often used in the biscuit industry in the form of syrups(see Section 5.3.2) 5.2 Relative sweetness Relative sweetness of sugar 62DE Glucose syrup Maltose 42DE Glucose syrup 30 DE is the dextrose equivalent. 5.3 Types of Syrup 5.3. 1 Syrups based on sucrose Liquid sugar (this is a somewhat confusing term given to a solution of sucrose)has 67% solids and 33% water Invert syrup is derived by hydrolysing sucrose into its components, dextrose and fructose. This is easily done with acid. The acid is neutralised after the reaction is complete. Amber to dark syrups vary from pale coloured syrups like golden syrup(which has about 38% invert sugars, with the rest sucrose)through darker types to treacle and ultimately molasses. As the colour darkens the flavour increases and becomes progressively sucrose-based syrups usually have 80% solids and 20% 5.3.2 Syrups derived from starch All syrups derived from starch usually have 70% solids and 30%
30 Biscuit, cookie and cracker manufacturing manuals monohydrate). Another lower sugar is fructose which is similar to dextrose but is much sweeter. (Fructose is a sugar that can be eaten safely by persons suffering from diabetes.) Maltodextrin is a mixture of partially hydrolysed molecules of starch. It has a low sweetness but is readily soluble. These lower sugars are often used in the biscuit industry in the form of syrups (see Section 5.3.2). 5.2 Relative sweetness Relative sweetness of sugars used in baking: Fructose Sucrose Dextrose 62DE Glucose syrup Maltose 42DE Glucose syrup Lactose DE is the dextrose equivalent. 173 100 74 60 32 30 16 5.3 Types of Syrup 5.3.1 Syrups based on sucrose Liquid sugar (this is a somewhat confusing term given to a solution of sucrose) has 67% solids and 33% water. Invert syrup is derived by hydrolysing sucrose into its components, dextrose and fructose. This is easily done with acid. The acid is neutralised after the reaction is complete. Amber to dark syrups vary from pale coloured syrups like golden syrup (which has about 38% invert sugars, with the rest as sucrose) through darker types to treacle and ultimately molasses. As the colour darkens the flavour increases and becomes progressively more bitter. All sucrose-based syrups usually have 80% solids and 20% water. 5.3.2 Syrups derived from starch All syrups derived from starch usually have 70% solids and 30% water
Glucose syrups, 42DE, 63DE, 90DE, etc at ambient tempera- es are very thick due to the ce of large molecules such as dextrins which are partially hydrolysed starch. Glucose syrups are generally not as sweet as sucrose syrups. The term DE is used to indicate the apparent concentration of dextrose, or other reducing sugars,and hence the sweetness and reducing power. Thus DE42 indicates that the syrup has a similar performance to a 42% solution of dextrose High fructose corn syrup(HFCS)is a type of glucose syrup. The hydrolysis of starch has been achieved with special enzymes that favour the production of fructose rather than dextrose. The concentration of fructose in relation to other sugars is in the range 40-90%. This means that the syrup is much sweeter in taste than a normal glucose syrup 5.3.3 Other syrups Malt extract is rich in the sugar maltose which although a disaccharide is a reducing sugar. Malt extract is used principally for its flavour. It is usually made from germinating barley by extracting water and concentrating the syrup to 80% solids Malt is rich in the enzyme amylase which breaks down starch and sugar When using malt extracts in biscuit doughs only non-diastatic syrup should be used in which the enzymes have been deactivated by heat. Honey is similar in composition to invert syrup. It is therefore a mixture of reducing sugars. Honey is expensive and is used principally for its flavour Lactose(may be crystalline) is a sugar derived from milk,a disaccharide (unit of dextrose plus unit of gallatose) 5.4 Uses and functions of sugars and syrups 5.4. 1 Uses in biscuit doughs the taste and structure of most biscuits Relatively large quantities of sucrose and syrups are used in all short doughs, smaller quantities in semi-sweet doughs and to a much lesser extent in cracker doughs and wafer batters. In short doughs there is not normally enough water in the formulation to allow all the sugar to dissolve so the crystal size of the sucrose used affects the eating characteristics of the baked biscuit
Sugars and syrups 31 Glucose syrups, 42DE, 63DE, 90DE, etc. at ambient temperatures are very thick due to the presence of large molecules such as dextrins which are partially hydrolysed starch. Glucose syrups are generally not as sweet as sucrose syrups. The term DE is used to indicate the apparent concentration of dextrose, or other reducing sugars, and hence the sweetness and reducing power. Thus DE42 indicates that the syrup has a similar performance to a 42% solution of dextrose. High fructose corn syrup (HFCS) is a type of glucose syrup. The hydrolysis of starch has been achieved with special enzymes that favour the production of fructose rather than dextrose. The concentration of fructose in relation to other sugars is in the range 4&90%. This means that the syrup is much sweeter in taste than a normal glucose syrup. 5.3.3 Other syrups Malt extract is rich in the sugar maltose which although a disaccharide is a reducing sugar. Malt extract is used principally for its flavour. It is usually made from germinating barley by extracting water and concentrating the syrup to 80% solids. Malt is rich in the enzyme amylase which breaks down starch and sugar. When using malt extracts in biscuit doughs only non-diastatic syrup should be used in which the enzymes have been deactivated by heat. Honey is similar in composition to invert syrup. It is therefore a mixture of reducing sugars. Honey is expensive and is used principally for its flavour. Lactose (may be crystalline) is a sugar derived from milk, a disaccharide (unit of dextrose plus unit of gallatose) 5.4 Uses and functions of sugars and syrups 5.4.1 Uses in biscuit doughs Sugars are important in the taste and structure of most biscuits. Relatively large quantities of sucrose and syrups are used in all short doughs, smaller quantities in semi-sweet doughs and to a much lesser extent in cracker doughs and wafer batters. In short doughs there is not normally enough water in the formulation to allow all the sugar to dissolve so the crystal size of the sucrose used affects the eating characteristics of the baked biscuit
Biscuit, cookie and cracker manufacturing man 5.4.2 Uses in biscuit filling creams In biscuit filling creams there is a need to have a smooth mouthfeel and rapid dissolution of the sugar in the mouth. Fine particle sized sucrose, icing sugar, is used. Sometimes some dextrose is used to reduce the overall sweetness. Dextrose (usually used as the monohydrate) has a negative heat of solution giving an attractive cool mouthfeel as it dissolves 5.4.3 Uses in jams and jellies Fixtures of sucrose and invert sugars are important in jams and jellies. The concentration of the sugars must be at least as high as 67% to prevent microbial spoilage and in jams used for biscuits the concentration may be as high as 78% 5.4.4 Use in marshmallow Marshmallow is a foamed mixture of sugar syrups and a gelling agent such as gelatin or agar agar. 5.4.5 Uses in chocolate Sugar is a major ingredient in chocolate. In the course of manufacture the chocolate is ground very finely so that it is possible to detect the sugar crystals when the chocolate is eaten 5.4.6 Function or sugars in biscuits For sweetness and favour. The brown sugars and sucrose syrups are valuable sources of flavour in biscuits For structure and hardness, particularly in short doughs. High levels of sucrose give hard glassy textures. This is because molten, concentrated sugar solutions, which are formed when the dough pieces are heated in the oven, set on cooling. If some glucose syrup is added to the formulation the harc ay a given level of sucrose. te. The sud not only for its sweetness but as a filler that dissolves eaten As a flavour enhancer and to make flavours seem correct small
32 Biscuit, cookie and cracker manufacturing manuals 5.4.2 Uses in biscuit filling creams In biscuit filling creams there is a need to have a smooth mouthfeel and rapid dissolution of the sugar in the mouth. Fine particle sized sucrose, icing sugar, is used. Sometimes some dextrose is used to reduce the overall sweetness. Dextrose (usually used as the monohydrate) has a negative heat of solution giving an attractive cool mouthfeel as it dissolves. 5.4.3 Mixtures of sucrose and invert sugars are important in jams and jellies. The concentration of the sugars must be at least as high as 67% to prevent microbial spoilage and in jams used for biscuits the concentration may be as high as 78%. Uses in jams and jellies 5.4.4 Use in marshmallow Marshmallow is a foamed mixture of sugar syrups and a gelling agent such as gelatin or agar agar. 5.4.5 Uses in chocolate Sugar is a major ingredient in chocolate. In the course of manufacture the chocolate is ground very finely so that it is not possible to detect the sugar crystals when the chocolate is eaten. 5.4.6 Function or sugars in biscuits For sweetness and flavour. The brown sugars and sucrose syrups are valuable sources of flavour in biscuits. For structure and hardness, particularly in short doughs. High levels of sucrose give hard glassy textures. This is because molten, concentrated sugar solutions, which are formed when the dough pieces are heated in the oven, set on cooling. If some glucose syrup is added to the formulation the hardness may be reduced at a given level of sucrose. As a bulking agent in creams and chocolate. The sucrose is used not only for its sweetness but as a filler that dissolves readily when eaten. As a flavour enhancer and to make flavours seem correct. Small
quantities of sucrose allow a much greater appreciation of certain flavours. Salt is another common flavour enhancer. Some flavours do not seem correct unless they are in a sweet context. Good examples are fruit flavours which are associated with sweetness and often acidity As a fermentation food. In doughs that are fermented, such as ream crackers, additions of small quantities of sugar encourage the yeast to grow more vigorously and hence speed the fermentation process. To aid surface coloration during baking. Only the reducing sugars do this. During baking the reducing sugars combine with amino acids from proteins(found in flour, milk products and eggs)in a complex reaction known as the maillard reaction. this reaction gives attractive foxy brown colours on the surface of baked goods. The higher the concentration of the reducing sugars present the darker the colours produced. The Maillard reaction is also more prevalent in alkaline than acid conditions and this is one of the reasons why sodium bicarbonate is used in biscuit recipes to As a decoration on the surface of biscuits. Sucrose crystals dusted on to the surface of dough pieces before baking adhere strongly and add to the attractive appearance of the biscuits. The size of the crystals is critical to obtain the desired effect. In some cases where hot oven conditions are used and the expansion of the dough piece is great during baking it is possible to melt th sucrose on the biscuit surface to obtain a sugar glaze 55 rtance of sucrose particle size The particle size of sucrose affects the following products Mouth feel. Important in sandwich creams and short dough biscuits. Small crystals feel smooth and dissolve quickly, larger nes give gritty or crunchy textures Rate of solution. When mixing doughs time must be allowed for luch of the sugar as possible to dissolve in the available water. There may be competition for this water between sugar and starchy materials. Thus if more sugar should be dissolved use a fine particle size. Spread control. Some short dough biscuits increase in diameter length and width during baking. These changes in size are usually
Sugars and syrupa 33 quantities of sucrose allow a much greater appreciation of certain flavours. Salt is another common flavour enhancer. Some flavours do not seem correct unless they are in a sweet context. Good examples are fruit flavours which are associated with sweetness and often acidity. As a fermentation food. In doughs that are fermented, such as cream crackers, additions of small quantities of sugar encourage the yeast to grow more vigorously and hence speed the fermentation process. To aid surface coloration during baking. Only the reducing sugars do this. During baking the reducing sugars combine with amino acids from proteins (found in flour, milk products and eggs) in a complex reaction known as the Maillard reaction. This reaction gives attractive foxy brown colours on the surface of baked goods. The higher the concentration of the reducing sugars present the darker the colours produced. The Maillard reaction is also more prevalent in alkaline than acid conditions and this is one of the reasons why sodium bicarbonate is used in biscuit recipes to increase the alkalinity. As a decoration on the surface of biscuits. Sucrose crystals dusted on to the surface of dough pieces before baking adhere strongly and add to the attractive appearance of the biscuits. The size of the crystals is critical to obtain the desired effect. In some cases where hot oven conditions are used and the expansion of the dough piece is great during baking it is possible to melt the sucrose on the biscuit surface to obtain a sugar glaze. 5.5 Importance of sucrose particle size The particle size of sucrose affects the following products: Mouth feel. Important in sandwich creams and short dough biscuits. Small crystals feel smooth and dissolve quickly, larger ones give gritty or crunchy textures. Rate of solution. When mixing doughs time must be allowed for as much of the sugar as possible to dissolve in the available water. There may be competition for this water between sugar and starchy materials. Thus if more sugar should be dissolved use a fine particle size. Spread control. Some short dough biscuits increase in diameter, length and width during baking. These changes in size are usually