Part I1 Major Baking Ingredients

Bakery Products: Science and TechnologyEdited by Y. H. Hui

Copyright © 2006 by Blackwell Publishing

7 Sweeteners7

W-K. Nip

Introduction Traditional Sugars and Syrups

sugars Cane Sugar Beet Sugar Baker's Special Brown Sugar Powdered Sugar Fondant and Icing Sugars Baker's Drivert Turbinado Sugar Invert Sugar

Starch Sugars and Syrups Maltodextrins High Maltose Syrups High Conversion Syrups (Corn Syrups) Dextrose Syrups Dextrose Monohydrate Dextrose Anhydrous High Fructose Syrup (42% Fructose) Enriched Fructose Syrup (55% Fructose) Fructose Crystals

Other Syrups, Sugar, and Juice Concentrates Molasses Refiner's Syrup Honey Sorghum Syrup Maple Syrup

tReviewers: Dr. Joannie Dobbs, Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI; Dr. Juscelino Tovar, Institute of Experimental Biology, Faculty of Sciences, Universidad de Central de Venezuela, P.O. Box 47069, Caracas 1041A, Venezuela.

Lactose and Whey Solids Raisin Juice Concentrate

High Intensity Sweeteners, Sweetener Extenders, and Bulking Agents

Saccharin(Sweet'n LowTM, Sugar Twin'") Aspartame (NutraSweetTM , Equal'") Acesulfame Potassium (Acesulfame-K'" ,

Sucralose (Splenda'") Neotame Cyclamate Alitame D-tagatose Thalose Polydextrose (LitesseTM in Holland) Lactitol (LactyTM in Holland)

Acesulfam TM)

Use of Sweeteners in Baked Goods Functionality of Sweeteners in Baked Goods Functional Considerations of Sweetener Systems Problems and Possible Solutions in Reduced Sugar and

Conclusion Acknowledgments References

Sugarless Baking

INTRODUCTION Sweeteners are important ingredients in bakery prod- ucts, even though they are not indispensable. Be- sides sweetening the product, sweeteners may also supply fermentability, fivor, browning functions, and humectant effects to the final products. Other functions such as appearance and product structure are also provided, depending on the formulation and the products. This chapter will give brief overviews

137

Bakery Products: Science and TechnologyEdited by Y. H. Hui

Copyright © 2006 by Blackwell Publishing

138 Part 11: Major Baking Ingredients

of the properties of common sugars, syrups, high intensity sweeteners, bulking agents, sweetener ex- tenders (Table 7.1), and their uses in bakery prod- ucts, followed by a discussion of the functionality of sweeteners in baked goods, functional considera- tions in sweetener systems, and problems and possi- ble solutions in reduced sugar and sugarless baking.

TRADITIONAL SUGARS AND SYRUPS SUGARS

Sucrose is the most common sweetener at the house- hold level, and it is one of the most important nutri- tive sweeteners in the food industry. According to the U.S. Food and Drug Administration (FDA) defi- nition, sugar is "sucrose" alone. It is a sweet carbo- hydrate (disaccharide), white when pure, and chiegi obtained from sugar cane or sugar beets. The terms cane sugar and beet sugar apply to the origin of the products, sugar cane and sugar beet, respectively. Chemically, there is no difference between cane sugar and beet sugar. Sucrose is a disaccharide made up of one molecule of fructose and one molecule of glucose joined together by an a-1,4 glycosidic bond, that is, a-D-glucopyranosyl P-D-fructofuranoside.

Table 7.1. List of Selected Sweeteners

Sugar (sucrose) is available in a wide variety of grain sizes to meet the particular requirements of various food products. Various sugar grain sizes are produced by precise boiling, variations in the capac- ity and &xibility of the screening system, and rig- orous control of all phases of production. Table 7.2 shows the typical screen analysis for granulated sugar used in the baking industry (Alexander 1998, Anonymous 1979, Chen and Chou 1993, Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Cane Sugar

Cane sugar is made by first crushing and shredding the cane stalks. The extracted juice is then treated to remove some of the nonsugars and impurities. Boil- ing of the syrup concentrates it and forms "masse- cuite," a mixture of sugar crystals suspended in syrup. The crystallized sugar is centrifugally sepa- rated from the syrup, called liquor. The product obtained is raw sugar. Further refining (repeated dissolving, concentrating, and crystallizing of the syrup) produces the white crystals called cane sugar (sucrose) in commerce (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Other Syrups, High Intensity Sweeteners, Traditional Starch Sugars Sugars and Juice Sweetener Extenders, Sugars and Syrups and Syrups Concentrates and Bulking Agents

Sugars Maltodextrins Molasses Saccharin (Sweet" LowTM,

Cane sugar High maltose syrup Refiners syrup Aspartame (NutrasweetTM ,

Beet sugar High conversion syrups Honey Acesulfame Potassium,

Baker's special Dextrose syrups Sorghum syrup Sucralose (Splenda'") Brown sugar Dextrose monohydrate Maple syrup Neotame Powdered sugar Dextrose anhydrous Lactose and whey Cyclamate

Fondant and icing High fructose syrup Raisin juice Alitame

Baker's Drivert Enriched fructose D-tagatose

Turbinado sugar Fructose crystals Thalose Invert sugar Polydextrose (Litesse'")

Lacitol

Sugar TwinTM)

Equal'")

(Acesulfam K'" , Acesulfam'") (Corn syrups)

solids

sugar (40% fructose) concentrate

syrup (55% fructose)

7 Sweeteners 139

Table 7.2. Typical Screen Analysis of Granulated Sugars for the Baking Industry

U.S. Opening

Screen inches Mfrs. or Fine Baker’s Fondant Baker’s Mesh No. mm (approx.) Granulated Special Powdered and Icing Drivert

Parts Retained by Screen Mesh 30 0.595 0.0234 20 40 0.420 0.0165 69 Trace 50 0.297 0.0117 9 2 80 0.177 0.0070 2 17 100 0.149 0.0059 35 0.1 140 0.105 0.0041 34 0.5 200 0.074 0.0029 12” 1.3 270 0.053 0.0021 2.6 325 0.044 0.0017 3.5 Thru 325 92.0 99 99

Source:Adapted from Chen and Chou 1993, Junk and Pancoast 1973, Pancoast and Junk 1980. ”Through 140 mesh.

Beet Sugar

Beet sugar is obtained by first shredding the beets. The beet juice is obtained by extracting the beet strips with hot water in a tank. This beet juice is sub- jected to a series of processes of purification, filter- ing, and concentrating to produce the white crystals called beet sugar.

Baker’s Special

Baker’s Special sugar was especially developed for retail bakers; is it has a uniform fine grain (80-140 mesh) that helps to produce uniform cell structures in cakes, thereby giving a maximum volume prod- uct. Bakers also use Baker’s Special for sugaring cookies and doughnuts (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Brown Sugar

Brown sugar is used extensively in bakery products. In the United States, brown sugar is made from fine grain sucrose by coating the crystals with cane mo- lasses as it is spun in a centrifuge. Cane refiners select various types of syrups in the refinery to give them the proper fivor, color, and clarity, and they boil the mixture in a vacuum pan to the desired grain size. This “massecuite” is then centrifuged to sepa- rate the brown sugar crystals and the liquor. In reality,

it is fine-grained sugar covered with a thin layer of dark syrup. Various grades are available, from medi- um or golden brown (#lo color grade) to dark brown (#14 color grade). Brown sugar is used often for its flavor; those sugars with the highest ash and organic nonsugar content are generally the ones with the strong brown sugar fivor. Brown sugar fivor is de- pendent on the origin of the raw sugars from which it is made. Hawaiian raw sugar, because the cane is grown in a mineral-rich volcanic soil, has a distinct- ly intense fivor. Raw sugars from the U.S. southern states and from certain Central and South American countries are derived from cane grown in rich allu- vial soil and have their own distinct mild fivor (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

In some other sugar producing countries, brown sugar consists of sugar crystals obtained from inter- mediate steps in the refining processes.

Powdered Sugar

Practically, powdered sugar is Extra Fine, or 6X to 8X (size grade). The purpose of this fineness is to give a creamy frosting or icing on cakes or some pastries. Because of the fine granular size of this powdered sugar, cornstarch is added to avoid cak- ing. A somewhat coarser powdered sugar, generally designated as 4X, is sometimes available. It has 65- 70% of its granular crystals passing through the U.S.

140 Part 11: Major Baking Ingredients

No. 325 sieve. Because it is larger in granular size, addition of cornstarch is not needed to overcome the caking problem (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Fondant and Icing Sugars

Fondant and icing sugars are ultrafine powdered sugars with a grain size of 20p and smaller. It is generally referred to as 1OX or 12X. With this grain size, the sugar is below the point of detection by the teeth and provides creaminess in cake icing. It is an art to produce fondant from scratch. In many parts of the United States, fondant sugar in the dehydrated cooked wet fondant or dry ground fondant forms is available. The dehydrated fondants include invert sugars in the correct proportion to yield the fine grain necessary in a superior fondant. Dry fondant sugars contain pulverized sugar classified to the proper fineness so the grains are not detectable by the teeth. These products must be reconstituted with liquid, but do not require cooking, and thus offer convenience to bakers and other food processors (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Baker’s Drivert

C&H Baker’s Drivert is a patented pure cane sugar product. It is a fondant sugar with a particle size averaging between 5 and 7 p. These microscopic sugar particles are formed into tiny clusters that are bonded together with invert sugar. Baker’s Drivert can be reconstituted with room temperature water into fondant with a very white appearance in a mat- ter of minutes, offering convenience to bakers. It contains approximately 8% invert sugar, most of which stays in solution in the form of syrup even when the sugar is dry. It can also be used with other ingredients to make special icings for pastries and cakes (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Turbinado Sugar

Turbinado sugar is raw sugar crystals separated in a centrifuge and washed with steam. Some molasses is removed in the washing process. Mineral matter, other solid matter, and invert sugar are also present in turbinado sugar crystals. It is generally off-white,

and usually 99%+ pure sugar. Its total sugar content is closer to that of refined sugar than that of raw sug- ar. Because turbinado sugar has a molasses fkvor, its taste may affect recipe results (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

Invert Sugar

Invert sugar is a combination of fructose and glu- cose produced by converting sucrose molecules into fructose and glucose in equal amounts. Invert sugar is recognized universally for its ability to absorb moisture from the air and to resist drying out, proba- bly due to the presence of fructose. This hygroscopic property offers a convenient way to control the mois- ture absorption properties in products like baked goods. Invert sugar is less readily crystallized than other sugars. This property offers the benefit of in- creasing solids content without the problem of crys- tallization.

Invert sugar is about 25% sweeter than cane sugar, and 50% sweeter than corn syrup, offering the bene- fit of the same sweetness with fewer calories. Invert sugar is available in the dry form as well as the liq- uid form. In the liquid form, it is less likely to sup- port fermentation than are syrups made from other sugars. It is also less viscous. Its solubility is greater than those of sucrose and dextrose (Junk and Pan- coast 1973, Pancoast and Junk 1980, Pyler 1988).

With its reducing power, invert sugar contributes to crust color. Caramelization with a rich appetizing color can be achieved at a lower temperature with- out overbaking. When used in cookie formulations, invert sugar prevents uneven moisture distribution and premature crystallization during the cooling period, avoiding checking and breaking problems in cookie manufacturing. The presence of invert sugar in cake formulations can provide moisture, texture, and reductants, with uniform grain. In icing technol- ogy, application of 5 1 0 % invert sugar in the formu- lation prevents the icing from premature drying and controls sucrose crystallization (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

STARCH SUGARS AND SYRUPS

Starch is a polymeric carbohydrate made up of mainly glucopyranose units aligned in linear (amy- lose) and branched (amylopectin) formations. It is the normal form of stored carbohydrate in plants and

7 Sweeteners 141

exists naturally in abundance. The principal sources of starch are corn (maize), cassava (manioc), wheat, potato, and so on. Because glucose provides a sweet taste, researchers developed the technology for using acid and/or enzyme(s) to release the glucose units from the starch granules, resulting in sweet syrups. Because of the abundance of corn produced in the United States, corn is used as the raw material from which to extract starch (cornstarch) and produce various “corn” syrups. The corn kernels go though the inspection, cleaning, steeping, germ separation, grinding, and screening separation steps in order to obtain the cornstarch. In other counties, people use various other starches (potato, wheat, cassava, etc.) to produce equivalent syrups, but they prefer to use the term starch sugars.

With the development of immobilized enzyme technology, selected xylose isomerase has been ap- plied in the conversion of glucose to fructose in these syrups. Fructose is about 2.5 times sweeter than glucose. This provides advantages in the food industry, as much less syrup is needed to provide the same sweetness. Figure 7.1 shows the relationship of maltodextrin, various syrups, and sugars derived

Starch

V

Dextri nization

1 pF Maltodextrin

Saccharification c y Maltose syrup

+ High conversion syrup

b Dextrose syrup - b Dextrose

lsornerjzation

-t High fructose syrup

- f Enriched fructose syrup

v Fructose crystals

Figure 7.1. Relationship of maltodextrin and types of syrups derived from starch. The syrups can also be dehydrated into their dry forms.

from starch. It should be noted that these syrups are also dehydrated into the dry form for easier trans- portation, storage, and use.

It is common to use the term dextrose equivalence (DE) to describe the total reducing sugars (calculat- ed as dextrose and expressed as a percentage of the total dry substance) in maltodextrins, dextrins, malt- ose and its syrups, and corn (glucose) syrups and their solids. DE has no meaning for fructose syrups and solids. They are classified by the percentage of fructose in the products.

Maltodextrins

Maltodextrins are polymers with a chain length of 5- 10 glucopyranose units that can be produced by controlled dextrinization with the enzyme a-amy- lase. These liquids (sometimes called syrups) are tasteless or slightly sweet; they are used not as sweeteners, but to add body. These bulking or filling agents have a dextrose equivalence (DE) of less than 20 (Katz 1986).

High Maltose Syrups

High maltose syrups are produced by a two-stage enzymatic (a- and p-amylases) hydrolysis to obtain a high maltose content (40-60%) in the final prod- uct. It can be concentrated to a very high solid con- tent without crystal formation. Maltose is 32% as sweet as sucrose (100%) and thus does not have much sweetening power in food products. However, it can serve as an excellent agent for controlling crystallization and hygroscopic properties of food products (Hoynak and Bollenback 1966).

High Conversion Syrups (Corn Syrups)

High conversion syrups (called corn syrups in the United States) are normally made by hydrolysis with acid, acid-enzymes, or mutiple enzymes. Acid hydrolyzes the starch molecules randomly, produc- ing dextrose, some maltose, some maltotetraose, and so on. Application of P-amylase to the starch slurry produces optimal quantities of maltose. On the other hand, a-amlyase produces only minor amounts of low molecular weights sugars, but major amounts of soluble higher saccharides. Amyloglucosidase (glu- coamylase) hydrolyzes the starch chains unit by unit, producing large amounts of dextrose in the

142 Part 11: Major Baking Ingredients

hydrolysis. Acid (usually hydrochloric acid) may be added to achieve the proper pH for the optimum enzymatic reaction, and subsequently neutralized by sodium hydroxide in the process. Thus dextrose syrups contain very small amounts of sodium chlo- ride, if it is not removed. Refinement with carbon and ion exchange resins further purifies the syrups. Appropriate single or combined processes employ- ing acid hydrolysis alone, acid hydrolysis combine with enzyme catalysis, or combinations of different enzyme catalysis can produce almost any mixture of starch conversion syrup with the chemical and phys- ical properties required for specific uses (Hobbs 1986, Horn 1981, Anonymous 2002).

Dextrose Syrups

Dextrose syrups contain glucose (dextrose), malt- ose, and higher saccharides. They are products of incomplete hydrolysis of starch. The hydrolysis is much more extensive than that required for maltose syrup, but a fairly high maltose content is main- tained to prevent glucose crystallization at high glu- cose concentrations (Duxbury 1993, Schenck 1986).

There are many high conversion syrups, ranging from dry to viscous. Table 7.3 lists some of the prop- erties of high conversion syrups. These syrups are commonly used as sweeteners in baking and other food industries. The common designation with dex- trose equivalence (DE) provides the user with the degree of reducing sugars present in a particular syrup. Corn sweeteners are generally classified into four types. Type I corn sweeteners in the DE 0-38 range possess a mild sweetening power. Their prin- cipal use is to provide textural (i.e., body and mouthfeel) and humectant effects (because of their low hygroscopicity). Type I1 corn sweeteners in- clude syrups in the 38-58 range; these syrups are the traditional syrups, but they also include specialty syrups called high maltose syrups. All the syrups in this category possess moderate sweetness. They are also used with other sweeteners such as sucrose or high fructose corn syrups to provide the proper sweetness. Some of their principal uses are to con- trol crystallization and to provide viscosity effects such as body and mouthfeel. Type I11 corn sweeten- ers covers the 58-73 DE range. These corn sweet- eners are used mainly for sweetness, fermentability, and browning reactions, and to a lesser extent for moisture control. Type IV corn sweeteners include

those syrups in the 73-99.5 DE range. They are also used for sweetness, fermentability, and browning reactions. Because of their osmotic effect, Type IV sweeteners have a preservative effect for low and intermediate moisture foods. It is also used as the substrate for conversion to high fructose corn syrups (Duxbury 1993, Schenck 1986).

However, reducing sugars differ in their corre- sponding sweetness. Conversion syrups with the same DE designation may not have the same sweet- ness. Glucose is twice as sweet as maltose, but still only 70% as sweet as sucrose. Because glucose and maltose are not as sweet as sucrose, they will give some sweetness to food products and, more impor- tantly, will provide high osmotic pressure, controlled hygroscopic properties, easy caramelization, and good fermentability (Duxbury 1993, Schenck 1986).

Dextrose Monohydrate

Dextrose monohydrate is manufactured by complete depolymerization of the starch substrate using acid and/or enzymes, and recovery of the product by crystallization. The crystals are recovered by wash- ing and centrifugation. The dried crystals have about 8.5% moisture. The mother liquor can be recycled to make a second crop of dextrose monohydrate (Dux- bury 1993, Schenck 1986).

Dextrose Anhydrous

Dextrose anhydrous is usually prepared by redis- solving the dextrose monohydrate and refining the resulting solution. This solution is concentrated to a very high solid content followed by the addition of seed a-D-glucose to induce crystallization. The an- hydrous dextrose crystals are separated by centrifu- gation, washed, and dried (Duxbury 1993, Schenck 1986).

The moist dextrose crystals can be dissolved to form a dextrose syrup with about 71% dry sub- stance. Dextrose (glucose) syrup can also be ob- tained by hydrolyzing starch to as high a degree as is technically possible. Dextrose has lower solubility than sucrose and is available more commonly in syrup form for the food industry, even though pure glucose crystals are available for food preparation and other purposes. This syrup is commonly used as a substrate to make high fructose syrup. It is also good as raw material for fermentation processes.

Tabl

e 7.

3. S

elec

ted

Pro

pert

ies

of S

ome

Com

mon

Sug

ars

and

Sta

rch

Sw

eete

ners

Maj

or S

ugar

Com

pone

nt(s

)

Suga

rISt

arch

Sw

eetn

ess

Bro

wni

ng

Swee

tene

r G

luco

se, %

Fr

ucto

se, %

Su

cros

e, %

M

alto

se, %

L

acto

se, %

R

atin

g Fe

rmen

tabi

lity

Cap

acity

Sucr

ose

100

100

Yes

N

o G

luco

se

100

70-8

0 Y

es

Yes

Fr

ucto

se

100

140

Yes

Y

es

Mal

tose

30

-50

Lim

ited

No

Mal

tode

xtri

n 1

Impe

rcep

tible

L

imite

d N

o H

igh

mal

tose

3

15-2

0 L

imite

d N

o

Cor

n sy

rup

19

50

Yes

Y

es

Dex

tros

e sy

rup

100

30-5

0 Y

es

Yes

H

FCS*

42

52

42

3 10

0 Y

es

Yes

H

FCS*

55

41

55

2 10

0-11

0 Y

es

Yes

L

acto

se

100

20

Lim

ited

No

Hon

ey

31.0

38

.5

1.5

7.2

97

Yes

Y

es

Map

le s

yrup

0-

11

fruc

tose

+

88-9

9 64

Y

es

Yes

Mol

asse

s 15

-21

15-2

1 31

-37

74

Yes

Y

es

Sor

ghum

syru

p 17

-18

17-1

8 34

-36

69

Yes

Y

es

syru

p

(DE

42)

gluc

ose

Sour

ce: A

dapt

ed f

rom

Hob

bs 1

986,

Hoy

nak

and

Bol

lenb

ack

1966

, LaB

ell

1992

, Mei

nhol

d 19

90.

"HFC

S =

Hig

h fr

ucto

se c

orn

syru

p.

100 4 55

14

144 Part 11: Major Baking Ingredients

High Fructose Syrup (42% Fructose)

High fructose syrup is made by isomerization of the glucose in high conversion syrup to fructose, using immobilized enzyme (selected xylose isomerase) technology. Fructose is 1.7 times as sweet as su- crose. The product normally has about 42% fructose content and 71% dry substance, with a sweetness almost equal to that of sucrose on a solid basis. It can be used to replace sucrose in baking and various other food applications. This syrup is also called iso- merose, isoglucose, or fructose-glucose syrup (Long 1986, Marx et a1 1990). When this syrup is made from corn, it is called high fructose corn syrup (HFCS) in the United States.

Enriched Fructose Syrup (55% Fructose)

Enriched fructose syrup is produced from high fruc- tose syrup by chromatographic separation of glu- cose and fructose. The fructose content in these syrups can be controlled to be 5590%. Higher fruc- tose content means less syrup is used for the same sweetness. The most common enriched fructose syrup has 55% fructose and is used widely by soft drink bottlers. Application in the baking industry is more limited. The glucose obtained from the chro- matographic separation can be marketed separately or recirculated to the isomerization process (Long 1986, Marx et al. 1990).

Fructose Crystals

Pure fructose is produced from enriched fructose syrup, by seeding, crystallizing, and separating the pure fructose crystals from the mother liquor. Dried fructose crystals have about 0.2% moisture (Andres 1986, Dziezak 1987).

OTHER SYRUPS, SUGAR, AND JUICE CONCENTRATES

Molasses

Molasses usually is a byproduct of sugar refining, but it can be a primary product (open kettle mo- lasses) of sugar production. It is a heavybodied and viscous liquid.

Open kettle molasses is a primary product ob- tained by concentration of the sugar cane juice di- rectly without removing any of the sugar and the use of artificial clarifying or preserving agents to the

point where crystallization sets in. The concentrated juice that is drained off constitutes the open kettle molasses. When properly aged, it acquires a rumlike flavor due to limited fermentation caused by certain strains of Torula yeast. It may be darker than other molasses, as no bleaching occurs during the manu- facturing process (Pyler 1988).

Unsulfited molasses imported from the West Indies is the finest type of molasses. It is the whole cane juice that has been clarified and evaporated to a heavier consistency. Unsulfited molasses has a light, clear color with delicate fivor and is sweeter than other molasses grades because it contains all the sugars of the original cane.

In the manufacture of sucrose from sugarcane, clarification with lime and treatment with sulfur di- oxide of the sugarcane juice remove considerable amounts of impurities from the syrup used for su- crose crystallization. When sucrose crystals are formed, the mother liquor is centrifuged off to recover the raw sugar crystals. The recovered moth- er liquid is the first molasses. Subsequent refining of the raw sugar crystals produces second, third, and blackstrap molasseses of different quality (Pyler 1988).

First molasses is somewhat darker in color and not as delicate in fivor as the unsulfited molasses. Second molasses is even darker in color and stronger in fivor than first molasses. Third molasses is very dark with a strong, often bitter, fivor. Black- strap is the final residue from which no additional sugar can be economically extracted. It is very dark and bitter tasting, and it is the lowest grade of mo- lasses produced. It is usually not used for human consumption. First molasses contains 35% sucrose and 37% invert sugar, whereas final (blackstrap) mo- lasses contains 32% sucrose and 23% invert sugar.

The fivor of molasses depends on its origin. The quality of molasses is governed by the maturity of the sugarcane, the amount of sugar extracted, and the method of extraction.

Because molasses is a viscous liquid, it is difficult to handle. To overcome this problem, manufacturers developed a dry, free-%wing product with a mois- ture of 3% that contains about 60-75% molasses solids; the balance of the product is partially hy- drolyzed starch or wheat %bur. The product is avail- able in both granular and fike forms with the dark brown color of molasses.

Molasses is used mainly for its fivor and sweet- ness, but it also imparts a pleasant color to crust and

7 Sweeteners 145

crumb in bakery products. Another unusual property of molasses is its acidity, which makes it valuable as a leavening agent. Molasses gives good results with cookies, as its natural acids interact with baking soda, releasing carbon dioxide, which raises cookie doughs. This reaction also affects the spread and spring of cookies, making the uniformity of molas- ses important. The presence of sucrose and invert sugars in molasses also makes it a good source of energy for yeast activity in fermented baked goods. When molasses is used for baking, the following cri- teria should be considered: color produced in the baked products, fivor, sugar content, solids content, ash, and product uniformity.

Refiner’s Syrup

A product that is closely related to molasses is refin- er’s syrup, a balanced processed syrup extracted from raw sugar. Its fivor is different from that of unsulfited and regular molasses, but serves similar functions. It is a standardized product used to uni- formly regulate dough fermentation of dark breads and dark bakery products and enhance their fivor. It can counteract the bitter taste of bran and germ and mask the gray-brown color of bran and germ in products made from whole wheat, cracked wheat, and other darker kurs. Refiners’ syrup is available in light, medium, and dark colors, providing a wide range of desirable crumb color for the products in which it is used (Hoynak and Bollenback 1966).

Honey

Honey is the nectar excreted by bees after they have collected the nectar from the kwer pollens. The excreted honey is stored in beehive comb cells and covered with wax cells for long-term storage. Honey is extracted from these cells by removal of the wax and centrifugation. Wax particles, foreign matters, and air bubbles are strained or filtered from this raw honey. Honey is usually mildly heat treated (pas- teurized) at 60-71°C (140-160°F) to destroy the os- mophilic yeast, delay crystallization, and lower the honey’s viscosity for subsequent processing (Pyler 1988). Controlled crystallization of the heat-treated honey produces “spun,” “creamed,” or “crystallized” honey. Dry or powdered honey is produced by drum drying (LaGrange and Sanders 1988).

There are more than 150 different kinds of honey, based on kral sources. Some of the prominent ones

include white clover, sweet clover, alfafa, rape, aca- cia, orange and other citrus, sage, buckwheat, and basswood. The four types most commonly used by bakers are orange blossom, clover blossom, sage blossom, and buckwheat honey. The color of these honeys ranges from water white to dark amber. Color is not an indication of quality; it is a result of the honey’s kral source and place of origin. Strength of fivor and color can be correlated, al- though there are exceptions to this rule. Clover or orange blossom honeys are light in color and fivor. Buckwheat honey is dark and has a strong, distinct flavor. Light-colored honey is more suitable for light-colored products such as bread and delicate cakes, while dark honeys are more suitable for hearty products like dark bran bread. Most food processors in the United States use a gold/amber honey blend with a sweet, typical fivor. Honey processors use the Pfund scale, which was developed for honey to determine the optical density readings that correlate to honey color and specifications (LaBell 1988).

Honey is a mixture of many substances, and its composition depends on the types of kwers from which the nectar is collected as well as the region and climatic conditions where the kwers grew; thus, different honeys impart various fivors to the products in which they are used. To offer consistent quality, honey packers produce honey by blending honey from various sources, analyzing its compo- sition, and continuously controlling its functional characteristics.

The average amount of total sugars in honey is 82.4%, with 25.2-44.4% fructose, 24.6-36.9% glu- cose, 1.70-1 1.8% maltose, and 0.50-2.90% sucrose. Water content in honey is 12.2-22.9%. Because of its moisture content, honey comes with fewer calo- ries, 304 kca1/100 g than sugar, which has 400 kca1/100 g.

Honey contains small amounts of niacin and ascorbic acid as well as different minerals at various levels. It has a pH of 3.9, making it very stable mi- crobiologically. Gluconic acid in honey contributes to its tartness (LaGrange and Sanders 1988).

Because honey has a high fructose content, it is sweeter than refined sugars and can be substituted for sugars in many baked and other products. Honey has a tendency to hold and contribute moisture to bread products, delaying dryness and crumbliness, and thus enhance the bread texture. To enhance moisture retention, it is a common practice to re- place 10-15% of a bakery product’s total sugar with

146 Part 11: Major Baking Ingredients

a balanced amount of honey. In Orange Blossom Honey Brownies, up to half the total sugar content can be replaced if the ratios of nonfat milk solids are changed and a suitable chemical leavening agent is added (Meinhold 1990).

Honey can be formulated into a sealing glaze with high fructose corn syrup and thus act as moisture- loss barrier in baked products such as pastries. Fruc- tose is not only a good sweetener, but also a good humectant and fivor agent. Honey in muffin formu- lations provides moisture and tenderness to the final product. Replacement with honey of over 50% of the total sugars in a specially developed high-bran formula muffin has been reported (Meinhold 1990).

Since fructose and glucose are the main sugars in honey, they can be fermented easily by the yeast in breadmaking formulations. Honey can be applied to the production of dinner rolls at the 8% level with- out changing the formulation except for water and the dinner roll production steps (Meinhold 1990).

With mostly reducing sugars in its sugar profile, honey browns easily during baking, adding a natural dark color to baked products such as bread, crackers, and other products. Honey maintains a distinct fi- vor that varies depending on its origin. Its presence in the formula presents a unique characteristic pre- ferred by consumers. Honey can be used in graham cracker formulations at the range of 2 1.5% plus 17% granulated sugars (LaGrange and Sanders 1988).

The viscous nature of honey makes it difficult to handle and scale accurately in the bakery. This prob- lem is resolved by offering the baker a "churned" honey form, plasticized honey with invert sugar and a honey-starch complex at a ratio of 75% honey to 23.5% starchpyler 1988).

Sorghum Syrup

Sorghum syrup (sweet sorghum syrup or sweet sor- ghum) is made from Sorghum bicolor (L.) Moench, whose stalks are sweet and juicy. The stalk of this sweet sorghum plant can reach 14 feet tall, and when harvested at the right stage of maturity (about 15.5-16.5" Brix, with 10-14% sucrose), it can yield a juice that can be processed into syrup.

The harvested stalks without leaves are first crushed to extract the juice. If the leaves are not removed, the stalks should be allowed to dry before squeezing the juice from the stalk. The crushed stalk (called bagasse) should be handled properly as feed for livestock.

The juice is filtered and settled to remove the impurities. Sweet sorghum juice contains about 4% starch, and it must be hydrolyzed before evaporation to avoid a pudding-like texture for the final product. Amylase enzymes are usually used to overcome this problem. Invertase is sometimes used to convert some of the sucrose into fructose and glucose to avoid crystallization. The juice is evaporated either in batch or continuous k w evaporators. The juice is then preheated to 160-180°F (71-82°C). It is then settled for 1-2 hours to reduce the amount of skim- ming left in the juice and to reduce the cook-off time. When the concentrated juice reaches 226- 230°F (108-110°C) or a density of 78-80" Brix, the syrup is removed from the evaporator to a cooling pan. When the temperature of this syrup cools down to 140-160°F (6O-7l0C), it is strained and placed in a large container. Another option is to pump the cooked syrup through a cooling pipeline system, strain it, and fill it into containers for canning. When the filling temperature is above 150°F (65.5"C), the syrup should not spoil during storage (Diver and Sampson 2003, LaBell 1992).

Sorghum syrup is evaluated on thickness, clarity, color, and taste. Overcooking darkens the syrup, and a better color will be retained if the syrup is cooled somewhat before it is canned. When the syrup reaches 126°F (52"C), it should have about 70% sugar and a density of 11.5 poundslgallon, at which point the evaporation should be stopped, and the syrup can be poured readily. Malt diastases are sometimes added to hydrolyze the remaining starch into glucose to avoid thickening and jelling. The col- or of the syrup ranges from dark amber to dark red- dish brown. Color develops during the concentration process. The unique sorghum fivor is more intense in the darker grades of syrup. Flavor comes from the natural compounds extracted from the sorghum plant and also develops during concentration. The pH of the syrup is 5.0-5.5, with an ash content of 2.5-4.5%, so the syrup serves as a buffer in food systems (Diver and Sampson 2003, LaBell 1992).

Sorghum syrup has been used as a sweetener for over a century in the United States and is produced in at least 2 4 states. It is not as popular as the other syrups and is considered as a delicacy. Baked goods like breads, cakes, pies, muffins, and cookies can be sweetened with sorghum syrup. It has a stronger taste than cane syrup. Sorghum syrup can be used to substitute cup for cup in any recipe that calls for molasses, honey, corn syrup, or maple syrup.

7 Sweeteners 147

The correct label for sorghum syrup in the United States is “sorghum syrup” or “pure sorghum.” “Sor- ghum molasses” is blend of sorghum and sugarcane syrup. The “Sweet Sorghum” logo from National Sweet Sorghum Producers and Processors Associ- ation guarantees that the product bearing the logo is pure sorghum.

Maple Syrup

The sap collected from the maple tree is a clear and colorless liquid with a faint sweet taste. This sap is concentrated to a light brown syrup. Differences in the biochemical composition of sap determine the grade of syrup produced. While each syrup is unique, the quality of all maple syrup grades must meet state and provincial inspection standards. Many factors affect changes in sap biochemistry, both in the plant itself and in the storage tank before evaporation. These partly determine the shade of coloration with- in and between syrup color grades, as well as their flavor.

Maple sap contains about 1.44% sugar, and 96% of this sugar is sucrose. The sap also contains small percentage of amino acids, organic acids, phenolic compounds, plant hormones, minerals, salts, and other components that are essential for the plant to maintain growth.

The considerable amount of labor involved in the collection of maple sap in the United States and Canada, and the small amount collected from each tree, make maple syrup a costly item. Therefore, its use in the bakery industry is very limited.

Lactose and Whey Solids

Lactose is milk sugar in its a-hydrated form. It is a crystalline product available in granular (through 100 mesh), fine ground (through 200 mesh), or pul- verized (through 325 mesh) form. It is a by-product of the cheese industry. It is produced through a crys- tallization process from sweet or limed whey. Com- mercial lactose monohydrate usually has at least 98% lactose (Anonymous 1977, Ash 1976, Nick- erson 1978).

Lactose is made up of one molecule of glucose and one molecule of galactose joined together by a p-1,4 glycosidic bond. It is a reducing sugar. Yeast usually does not utilize lactose. However, if lactic acid bacteria are present, as in source sourdough, the lactose can be hydrolyzed into glucose and galac-

tose, and the yeast can utilize the glucose. Another option is to add lactase to the formulation to help hydrolyze the lactose.

The main limitation in using lactose in bakery products is the problem of lactose intolerance for consumers. However, with the commercial avail- ability of lactase at the retail level, lactose intoler- ance is no longer a real issue in developed countries, although it may be still a problem in areas where lactase is not readily available.

In baking, lactose is often used at the level of 3- 4% of the total weight of ingredients to replace sucrose, for a variety of functional benefits. Com- pared with other sugars, lactose offers the following benefits : fivor enhancement, emulsifying action, browning, low sweetness, tenderizing effect, volume improvement, and improved quality and shelf life (Anonymous 1977, Ash 1976, Nickerson 1978).

Lactose excels in absorbing fivors, aromas, and color as compared with other sugars, and it has been used as a carrier for these compounds. Due to this absorption-carrier ability, lactose retards the loss of flavor, color, and aroma during baking and proc- essing (Anonymous 1977, Ash 1976, Nickerson 1978).

Lactose improves the emulsifying efficiency of shortening, resulting in a more uniform cell struc- ture and desirable texture. At the same time, it can promote good distribution of ingredients with mini- mum mixing. Lactose extends the shortening in bak- ery products, enabling reduction of fat in certain recipes (Anonymous 1977, Ash 1976, Nickerson 1978).

Lactose is a reducing sugar and interacts with amines in the formulation to form typical nonenzy- matic Maillard reaction products. Since lactose is not fermented by yeast or modified to a great extent during processing, it is available for the desired browning reactions. Lactose begins caramelization at 150-160°F (65.5-71°C), and turns brown at 175°F (79.4”C). It produces a highly fivorful and golden-brown crust. The addition of lactose to the formulation helps maintenance of the desired golden- brown color throughout the baked product’s shelf life (Anonymous 1977, Ash 1976, Nickerson 1978).

At the common usage level in baked products, lac- tose is about 30-35% sweet as sucrose. The partial replacement of sucrose with lactose results in similar or improved texture, color, and aroma, but with low- er sweetness and calories. This is beneficial to con- sumers controlling calorie intake and preferring less

148 Part 11: Major Baking Ingredients

sweet products (Anonymous 1977, Ash 1976, Nick- erson 1978).

Lactose has the ability to bind water and subse- quently maintains moisture in the final product with- out making it soggy. The end product is a more ten- der, moister, better eating product. This tenderizing effect of lactose in bakery products allows a reduc- tion of shortening and sugar in the formulation, yet enhances the texture, fivor, and keeping qualities of the product (Anonymous 1977, Ash 1976, Nicker- son 1978).

Under optimum conditions, lactose can increase bread and cake volumes quite significantly. This increase in volume may be due to the tendering effect of lactose, with its ability to strengthen the cell walls in bread and cake. The caramelization and Maillard reactions are known to generate carbon dioxide and thus also contribute to volume increase (Anonymous 1977, Ash 1976, Nickerson 1978).

Also due to the tenderizing effect of lactose, prod- ucts made with added lactose and reduced sucrose and shortening (both are beneficial effects of lactose discussed earlier) have a longer shelf life. Shelf life is claimed to be extended at least 50-60%, signifi- cantly increasing the keeping quality of bread and cakes (Anonymous 1977, Ash 1976, Nickerson 1978).

Whey solids are also by-products of cheese man- ufacturing. In the past, lactose-containing whey was discarded and discharged into sewage lines. After the enactment of the Environmental Protection Act in the United States, this practice became costly, and the cheese industry started to recover the whey and process it into whey solids, and they further devel- oped the membrane filtration technology to separate the lactose from the whey proteins. The whey solids and lactose are now commonly used in the baking industry as sweeteners and for other purposes.

Raisin Juice Concentrate

Raisin juice concentrate is a natural product with amber to dark brown color. It is prepared by leach- ing the raisins with water in several stages, to pro- duce raisin juice, followed by vacuum concentration to 70” Brix. The concentrate does not require any preservative for prolonged storage as the sugar con- centration and other components in the concentrate can inhibit mold spoilage. It contains mainly re- ducing sugars (about 85-95%), resulting in faster

browning in baked goods. The tartaric acid present naturally in grapes contributes to leavening action, yielding enlarged loaf volume. The pectin from the grapes also provides a humectant effect, producing softer and moister finished baked products. Raisin concentrate is a natural brown colorant, giving a slight brown color to the dough and the finished product. A commonly recommended usage level is 9-12% of the kur, with reduced usage of other sweeteners such as sucrose or HFCS to compensate the sweetness in the formulation.

Table 7.3 lists some of the major components in sugars and syrups and some of their respective prop- erties (sweetness rating, fermentability, and brown- ing capacity).

HIGH INTENSITY SWEETENERS, SWEETENER EXTENDERS, AND BULKING AGENTS Many high intensity sweeteners are available for the food industry. The use of high intensity sweeteners in bakery products was first initiated to satisfy dia- betics who must control their sugar intake. When saccharin and cyclamate were the major high inten- sity sweeteners available, manufacturers for low calorie bakery products did not have many choices. In the past 25 years, the availability of aspartame, acesulfame potassium, sucralose, neotame, alitame, D-tagatose, thalose, and others in many countries have assisted in the development of low-calorie bak- ery products. There are also less common high in- tensity sweeteners, such as steviosides, glycyrrhizin, dihydrochalones, and L-sugars, that are used in some countries or are being investigated. It should be noted that use of high intensity sweeteners in food products is regulated in every country. High intensity sweeteners that are approved for use in one country may not be permitted in another country. The follow- ing sections describe some of the basic properties of the more common high intensity sweeteners, some of the problems that occur when high intensity sweeteners are used, and possible solutions (Olinger and Velasco 1996).

SACCHARIN (SWEET” LowTM, SUGAR TWIN^^)

Saccharin, an organic petroleum compound discov- ered by accident, has been used as an artificial sweetener for over a century. It is one of the earliest

7 Sweeteners 149

artificial sweeteners. The common forms of saccha- rin used in the food industry are the white crystalline powders of sodium or calcium salts. The acid form is seldom used in the food industry because of its solubility. It is 300-400 times (200-700 times in some literature) as sweet as sucrose, and slow to onset. It delivers a persistent bitter, metallic after- taste at high concentrations. It does not contribute calories and is not metabolized in the human body. Saccharin was suspected to be carcinogenic, but this claim was not supported by hard scientific evidence. Currently, saccharin is available in the United States and many other countries without any warning label. However, it is not available in Canada. It can be used in baked goods for its sweetness, but will not con- tribute to other functional properties, as the quantity used is very low. Nowadays, its use is not as com- mon as is the use of the newer high intensity sweet- eners (e.g., aspartame and Acesulfame KTM) (Anon- ymous 1979, Best and Nelson 1993, Giesse 1993).

ASPARTAME (NUTRASWEET~~, EQUAL TM)

Aspartame is made of two amino acids-L-aspartic acid and L-phenylalanine-that have no sweet taste by themselves. Chemically, aspartame is L-aspartyl- L-phenylalanine methyl ester. It is a GRAS (gen- erally recognized as safe) sweetener made from protein components and is therefore classified as nu- tritive. It is 160-220 times as sweet as sucrose. It is usually sold in packets and tablets for tabletop use.

Aspartame has the clean, sweet taste of sugar without the metallic, bitter aftertaste often associat- ed with saccharin and cyclamate. This amino acid sweetener can be used in combination with other sugars or high intensity sweeteners to produce syn- ergistic effects in low- or reduced-calorie products. Aspartame also enhances and extends fivors such as citrus fivors. However, it can also enhance bitter- ness when used with bitter cocoa, but this problem can be overcome by using cocoa with a different alkalinity. Aspartame is stable in the dry form. In solutions, its stability is a function of three factors, time, temperature, and pH. As the time at a given temperature increases, the percentage of aspartame remaining unchanged decreases. Similarly, as the temperature increases for given process time, the amount of aspartame remaining unchanged also de- creases. Decomposition follows simple first-order kinetics. Aspartame is more stable at a pH value be-

tween 3 and 4 than at higher pH values (Homler 1984).

Aspartame is hydrolyzed into the two amino acid components that are metabolized in the normal hu- man body, and it generates 4 kcal/g. Its decomposi- tion product, phenylalanine has been a concern for phenylketonuric (PKU) heterozygotes. It was con- cluded that the level of phenylalanine is well below the safety limit under normal usage and can be toler- ated with little clinical significance. However, the statement, “Phenylketonurics: Contains phenylala- nine,” is required on the labels of all products con- taining aspartame in the United States to safeguard children with PKU and to make sure their parents are aware of the phenylalanine in aspartame.

Methanol, one of the decomposition products of aspartame, was also a concern when aspartame- containing beverages were exposed to high tempera- tures. It was concluded that the amount of methanol produced is also well below the safety limit and does not pose a health hazard. Other clinical studies were also conducted. These scientific studies concluded that consumption of aspartame by normal humans is safe and is not associated with serious adverse health effects. Individuals who need to control their phenylalanine intake should handle aspartame like other source of phenylalanine (Council on Scientific Affairs, AMA 1985).

Because aspartame can decompose when exposed to higher temperatures under certain conditions, its original form is not suitable for baking. Instead, the manufacturer for aspartame has developed an encap- sulated form that can withstand the heat during bak- ing and prevents loss of sweetness intensity in baked goods and baking mixes. Essentially, aspartame is granulated and encapsulated with proprietary food grade materials to protect it throughout the tempera- tures of the baking process. These materials are said to act as a time-temperature release system that releases aspartame at the end of the baking process, thus protecting aspartame until the product stops baking. Because aspartame is released at the end of the baking process, it is at that point in a reduced moisture system and is safe from moist heat and breakdown. Products using encapsulated aspartame have shelf life of about 1 week at room temperature, the same as products using sugar. The shelf life will be longer if the products are sold frozen. The amount of material used to encapsulate aspartame is very small and therefore has no impact on the final

150 Part 11: Major Baking Ingredients

product, either in terms of quality or calories (Pszczola 1988).

Encapsulated aspartame is very suitable for top- pings, frostings, and fillings in baked goods, at the range of 30-50%. When aspartame is used in place of sugars in cakes, for example, it does not con- tribute to volume, structure, and tenderness as sugar does in cakes made with sugar. Adding bulking agents will provide the volume usually provided by sugar. At the same time, these bulking agents have to provide other benefits the sugar provides, but with- out the calories. Premixes containing aspartame and bulking agents together with the other ingredients are made available to consumers and food pro- cessors for their convenience (Pszczola 1988).

ACESULFAME POTASSIUM (ACESULFAME-K~~, ACESULFAM TM)

Acesulfame-K'", a derivative of acetoacid, and a methyl derivative of oxathiazinones, is another GRAS sweetener. It is a colorless crystalline powder. This sweetener is water soluble and stable at normal temperature and moderate pH. It is approximately 200 times sweeter than sucrose based on a 3% aque- ous solution. Its sweetness is similar to aspartame, but more stable, without calories, and possibly cheaper.

Acesulfame-K'" has a clean, quickly perceptible, sweet taste that does not linger. Its taste is also stable over time in solids and liquids, and after exposure to heat. These qualities are in contrast to aspartame, which is not stable when stored in liquid and/or exposed to heat, and with saccharin and cyclamate, which have a bitter aftertaste to many consumers. Acesulfame-K'" can be combined with other sweet- eners to obtain a blend that tastes like sugar, but with greater sweetening intensity than the individual parts of the blend, allowing less sweetener to be used. Over 20 countries, including the United States, approve the use of Acesulfame-K'" in various prod- ucts. Acesulfame-K'" is not metabolized and does not have any pharmacological effects (Peck 1994).

Acesulfame-K'" is very suitable for bakery appli- cations. It does not decompose at the baking temper- atures until 225°F (107°C). It is stable during ex- tended storage. It also does not decompose under sunlight and can be stored like other dry bakery ingredients. Acesulfame-K'" is stable in both the acid and the alkaline conditions typically found in bakery products. It dissolves easily in water and can be added at any stage of the mixing process, either

with solid or liquid ingredients. It can be used with various nutritive sweeteners. Usage level of Acesulfame-K'" in baked goods varies among for- mulations, ranging from 700 to 1200 ppm, or higher for frostings and icings. The amount of bulking agent(s) used in the formulation is a deciding factor in the usage level of Acesulfame-K@ (Peck 1994).

SUCRALOSE (SPLENDA~~)

Sucralose, a white, crystalline, nonhygroscopic sol- id produced by selective chlorination of the sucrose molecule, is another GRAS sweetener available to the bakers. It is the only high intensity sweetener made from sucrose. It is 600 times sweeter than sucrose. It is very stable in the solid form and in solution. Under normal baking conditions, it will not decompose. It has stability and high water solubility. It has a sweetness profile like that of sucrose, with- out the bitter aftertaste. Sucralose is a very versatile high intensity sweetener, combining excellent sta- bility in liquid and heat-processed food products, and sweetness intensity greater than that of many currently approved high intensity sweeteners. It does not interact with the ingredients in bakery for- mulations. It is not metabolized in the human body, and therefore does not contribute any calories to the diet. It is also noncariogenic-does not promote tooth decay. Manufacturer's suggested usage of su- cralose in bakery products (McNeil Specialty Prod- ucts Co.) ranges from 175-225 pprn in apple pie fill- ings to 200-250 pprn in cheesecake, 200-300 pprn in crackers and brownies, 300-500 pprn in cookies, and 500-600 pprn in cakes. Its application in bakery goods was approved in Canada in 1991.

NEOTAME

Neotame was approved by U.S. Federal Drug Ad- ministration in 2002 as a nonnutritive sugar substi- tute. It is a derivative of the dipeptide phenylalanine and aspartic acid. Its chemical name is [(3,3- dimethylbutyl) -L-alpha-aspartyl] -L-phneylalanine- 1-methyl ester (Code of Federal Registration 2002). It has a sweetness rating of 7000-13,000, It is a free- flowing, water-soluble, white crystalline powder that is heat stable and can be used in baking and other food applications. It has a clean sweet taste without a bitter, metallic aftertaste. It can be used as a sweet- ener and fivor enhancer in foods and beverages (Council on Calorie Control 2004).

7 Sweeteners 15 1

CYCLAMATE

Like saccharin, cyclamate was discovered by acci- dent, in 1937. Its chemical name is cyclohexane sul- fonic acid. It was probably the second artificial sweetener used extensively worldwide. It is 30-60 times as sweet as sucrose, tastes much like sucrose, and is heat stable. Its sweetness has a slow onset and persists for a long time. It is metabolized in the body to cyclohexylamine. Like saccharin, it has a bitter aftertaste, but when used in combination with sac- charin (10 parts cyclamate to 1 part saccharine), the bitter aftertaste associated with each compound is significantly suppressed, and can only be detected at high concentrations. It is available in its acid form and as sodium or calcium salts (Anonymous 1979).

In 1970, based on an experiment involving the feeding of saccharin and cyclamate together to rats, a research team in Canada claimed that cyclamate may be carcinogenic. The FDA thus banned the use of cyclamate in the United States. However, this claim has never been proven by subsequent experi- ments. Instead, subsequent experiments showed that cyclamate is not carcinogenic. In fact, an impurity in saccharin (0-toluenesulfonamide) was suspected to be the cause of the problem, causing the FDA to issue a warning on the possible carcinogenicity of saccharin until 1991. Recently, the manufacturer for cyclamate has submitted a petition to the FDA with additional data to support the safety of cyclamate. This petition is still pending and the use of cycla- mate in the United States has not been reapproved. However, cyclamate is available in Canada as a tabletop sweetener and is used in Canada and many other countries in low-calorie food products. Like saccharin, the usage is small and will not contribute to the structure of any baked products.

ALITAME

Alitame is made by chemical synthesis and contains the amino acids L-aspartic acid, D-alanine, and a novel amide substitution. It is a white crystalline, odorless, nonhygroscopic powder. It is very soluble in water. Alitame has very high intensity sweetness, about 2000 times as sweet as sucrose in 10% solu- tions. It has a clean sweetness with no off notes or unpleasant aftertaste. It is partially metabolized and contributes to a theoretical maximum of 1.4 kcal/g. With its very high sweetness intensity, its caloric contribution is negligible. It has gone through the

traditional safety studies as set forth for food addi- tive petitions. Alitame exhibits good stability under a wide range of baking conditions, typically better than 80% is retained in the baked product. The usage is between 0.008 and 0.012% in cake and brownie formulations. Its use as a sweetener is pending FDA approval (Duff and Sigman-Grant 2000, Freeman 1989). However, it is approved for use in foods and beverages in Australia, New Zea- land, Mexico, the People’s Republic of China, and Mexico.

D-TAGATOSE

D-tagatose is a reducing monosaccharide that occurs naturally in some cheeses, yogurt, cocoa, dates, and heat-treated milk products. It is derived from whey and is considered a natural product in Hong Kong and Australia. It is a six-carbon sugar whose molec- ular structure is very similar to that of fructose, but with one carbon bond inverted. The altered structure renders it unavailable to the human body, and thus it does not contribute any calories.

D-tagatose is a white powder with very similar sensory and physical properties to those of sugar. It has no cooling effect, aftertaste, or potential for off taste. Its taste and fivor are very comparable to those of sucrose, more so even than fructose or glu- cose. It is about 92% as sweet as sugar and can be substituted almost one for one for sugar. The beauty of D-tagatose is that it has essentially the same phys- ical properties as sucrose, so little or no reformula- tion is needed in applications that currently contain sucrose; this is unlike many sugar alternatives. D- tagatose is more expensive than sucrose, but it would be competitive with other ingredients with similar applications; in some cases, this would in- clude a bulking agent as a sweetener, containing additional calories (Kevins 1996).

THALOSE

Thalose has no sweetness of its own but makes sucrose sweeter. It is a sweetener extender that is used mainly in invert syrup. It can replace at least 10% of the sugar used. It has no caloric value and works instantly without special preparation. It has no effect on fivor and aroma and has no unpleasant aftertaste. It is a GRAS ingredient with value in bak- ery and other products (Giesse 1993).

152 Part 11: Major Baking Ingredients

POLYDEXTROSE (LITESSE~~ IN HOLLAND)

Polydextrose is a designed product. The materials used in its production are an 89: 10: 1 mixture of dex- trose, sorbitol, and citric acid. It provides the bulk, texture, mouthfeel, and functional attributes of sugar and other caloric sweeteners. It is partially metabo- lized in the body and contributes only 1 kcal/g. It is an FDA-approved multipurpose additive that may be used in accordance with good manufacturing prac- tice as a bulking agent, formulation aid, humectant, and texturizer, and it should appear on the product label. It can be used in baked goods. When con- sumed in large amounts, it has laxative effect in some consumers. Regulations require a single ser- ving of food containing more than 15 g of polydex- trose to be labeled, “Sensitive individuals may expe- rience a laxative effect from excessive consumption of this product” (Giesse 1993).

LACTITOL (LACTY TM IN HOLLAND)

Lactitol is a disaccharide sugar alcohol made from lactose by catalytic hydrogenation. Chemically, it is 4-0-(~-galyactosyl)-D-glucitol. It is a nonhygro- scopic, crystalline material with a sweetness 40% that for sucrose. It has a clean, sweet, sugar-like taste without an aftertaste. It behaves like sucrose in food processing, which makes the ingredient an ideal sweetening agent for the formulation of products without sugar, where it provides both sweetness and bulking properties. However, it is a nonreducing sugar alcohol that does not take part in Maillard browning reactions or enzymatic degradation. It is very stable under acid and alkaline conditions and at high temperatures. It has a reduced caloric value of 2 kcal/g, and it is noncariogenic and suitable for dia- betics. In most applications, it can be used in con- junction with high intensity sweeteners such as aspartame, Acesulfame-K, or saccharine (Blankers 1995).

USE OF SWEETENERS IN BAKED GOODS For fermented bakery products, the use of sugar and/or syrups is common practice, except for a few cases. For crackers, cookies, and cakes, the use of sweeteners, either traditional sugars/syrups or high intensity sweeteners, depends on their formulations.

Maltodextrin, glucose syrup, dextrose, high fruc- tose corn syrup and fructose crystals, and other sweeteners are used in the manufacture of baked goods such as biscuits, breads and rolls, cakes, cookies, crackers, doughnuts, frosting, icings and glazes, pies, and pretzels independently or in com- binations of two or more. The only exception is breads and rolls that do not use fructose crystals (Anonymous 2002). The amount of sugars and syr- ups used in baked goods varies widely among groups of products, and also within groups. It may range from 0 to 40%. Table 7.4 lists the percentages of sweeteners used in each group of baked goods. Today, high intensity sweeteners are also used fair- ly commonly in baked goods. The promotion of low carbohydrate (low carb) foods encourages the use of high intensity sweeteners in baked goods. It should be noted that the amount of sweetener(s) used in each product differs based on the manufac- turer’s formulation, usually in the range of 0.1-2%, depending on the kinds of sweeteners used. In addi- tion, the use of high intensity sweeteners in bakery products is regulated by the corresponding agency of each country.

It should be noted that the most common storage problem of granulated sugar is caking caused by the repeated absorption and loss of moisture by sugar crystals. When granulated sugar is exposed to high relative humidity for a long period of time, moisture absorbed by the sugar crystals dissolves the sugar crystals, forming a thin layer of syrup. When the sugar is exposed to lower relative humidity, the moisture evaporates and recrystallizes the sugar crystals, cementing the crystals together. As this proceeds, a large lump is formed. The severity of the caking depends on how much moisture is ab- sorbed.

Baker’s Special is very susceptible to caking. Powered sugar, and fondant or icing sugars are even more sensitive, so cornstarch is added to powered sugar to minimize the problem. Powdered sugar contains about 3% cornstarch, and fondant and icing sugars contain about 4.5% cornstarch. Storing these sugars in moisture-barrier-ply, multiwall paper bags (commonly used in the United States) or similar containers helps slow down the penetra- tion of moisture. Plastic bags, used in other coun- ties, are also a promising solution to the problem (Junk and Pancoast 1973, Pancoast and Junk 1980, Pyler 1988).

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Table 7.4. Usage Range of Sweeteners in Bakery Products

Parts Sugar and Bakery Product Syrup (based on Bakery Product Amount, % Category 100 parts kur) Category of total weight

Bread, Home style 3 Bagels 0-8 Bread, Mixed grain 4-8 Breads and rolls 0-8 Bread, No-time 5.6 Brownies 20-40 Bread, Premium 7.1 Cakes 25-30 Bread, Raisin 8 Cookies 20-40 Bread, Rye 0-4 Muffins 25-30 Bread, Wheat 8-15 Sweet dough products 10-15 Bread, White hearth 2 Bread, White pan 6-8.5 Icings 55-90 Cookies 4-70 Crackers 3-35

Doughnut mix 38.5 Doughnuts, yeast-raised 8-12

Pie crust 3-8 Pretzels 0

Danish sweet goods 20

Hamburger (soft) bun 12

Puff pastry 0 Source:Adapted fromFaridi 1991, Kulp 1991, Nelson 2000.

Tables 7.5,7.6, and 7.7 are, respectively, recentsur- veys conducted in Honolulu on the usage of sweet- eners in breads; buns, bagels, and doughnuts; and crackers. It is clear that the use of one or more sweeteners in breads is fairly common (Table 7.5). High fructose corn syrup is used very commonly in breads, and molasses is used more often in wheat and multigrain breads. There are also a few bread products that do not use sweeteners at all. In the buns, bagels, and doughnuts group, the usage of sweeteners is not as diversified as in the bread cate- gory (Table 7.6). In the cracker category, sucrose is used in every product surveyed (Table 7.7). High fructose corn syrup is also used in five out of the nine subcategories of crackers. There are also prod- ucts that do not use sweeteners at all, such as water and rye crackers. About one-third of the savory crackers surveyed do not use sweeteners at all, but about half of the products surveyed use high fruc- tose corn syrup and/or sucrose. It is interesting to note that raisin juice, which contains fructose and dextrose, is now used in some products instead of traditional sugars and syrups. It is a newcomer in the sweeteners category.

FUNCTIONALITY OF SWEETENERS IN BAKED GOODS Baked goods consist of two main categories: yeast- raised goods and those that do not use yeast as the leavening agent. In yeast-raised goods such as bread, yeast utilizes the sugar (sucrose, glucose, or fructose) to produce the alcohol and carbon dioxide that help raise the products. However, yeast does not consume all the sugar. What remains contributes to the fivor, volume, aroma, and crust color of the product, while also helping retain moisture to extend shelf life. In non-yeast-raised goods, sugar is used mainly for its contribution to taste and fivor, and also to volume. In addition, sugar provides a tender- izing effect in these products.

In cookies, sugar contributes to the sweetness, spreading, and crispiness of the product. In addition, it provides a pleasing overall appearance, including a smooth grain and the appealing golden brown color of homemade cookies. Cakes with higher sug- ar content tend to be more tender and moist. Table 7.8 summarizes the major functions of sweeteners based on various categories of products. It is clear that each sweetener has its own functions in each

Tabl

e 7.

5. U

se F

requ

ency

of S

wee

tene

rs in

Bre

ads

(n)

in a

Hon

olul

u S

uper

mar

ket i

n Ju

ne 2

004

Mul

ti-

Hon

ey

Low

W

hite

W

heat

So

urdo

ugh

Lig

ht

Dar

k gr

ain

& O

at

Cal

orie

Fr

ench

S

wee

t B

read

D

inne

r Sw

eete

ners

B

read

B

read

B

read

R

ye

Rye

B

read

B

read

B

read

B

read

B

read

S

tick

s R

olls

Hig

h fr

ucto

se

13/1

5”

717

111

111

111

113

112

116

Sucr

ose

or

6/15

31

7 11

3 11

2 11

2 31

3 co

rn s

yrup

liqu

id

sucr

ose

Dex

tros

e 1/

15”

Cor

n sy

rup

213

Ref

iner

s sy

rup

2/15

M

aple

syr

up

1/15

” H

oney

4/

15

217

213

212

116”

M

olas

ses

417”

21

3 11

6”

Rai

sin

juic

e 21

7 21

3”

316”

A

cesu

lfam

e K

1/

15

316

Mal

titol

21

6

Bro

wn

suga

r 11

7 21

3 11

2 11

6 11

1 11

1

soli

ds

Whe

y so

lids

/ 21

3 11

1 11

1 la

ctos

e

Not

e: N

umbe

r in

dica

tes u

sage

ratio

(fr

eque

ncyi

n) in

sam

ples

surv

eyed

in

each

cat

egor

y.

”Inc

lude

s usa

ge o

f <

1 o

r 2%

.

Non

e 1/

15

112

111

7 Sweeteners 155

Table 7.6. Use Frequency of Sweeteners in Yeast-Fermented Products Other Than Regular Breads (n, Buns, Bagels, and Doughnuts) in a Honolulu Supermarket in June 2004

Hot Dog Hamburger Sandwich Plain Sweeteners Buns Buns Bun Bagels Doughnuts

High fructose corn syrup 717 414 Sucrose or liquid sucrose 111” 213” Dextrose 111” 111” Corn syrup solids 213 Molasses 113 Raisin juice 117 Maltodextrin 111”

Note: Number indicates usage ratio (frequencyin) in samples surveyed. ”Includes usage < 1 or 2%.

product. Some sweeteners can have similar func- tions in different groups of products. However, the requirements for sweeteners in each category of baked products vary according to the characteristics of the products and the manufacturing processes.

FUNCTIONAL CONSIDERATIONS OF SWEETENER SYSTEMS When applying sweetener(s) in baked goods, some considerations must be made based on the appear- ance, mouthfeel and texture, fivor, marketing and regulatory issues, storage and handling, process and preparation, and reactivity of the sweeteners them- selves and of the final products. Table 7.9 lists the categories of functional consideration for sweetener systems in baked goods and the items to be consid- ered for each category.

PROBLEMS AND POSSIBLE SOLUTIONS IN REDUCED SUGAR AND SUGARLESS BAKING It should be noted that when high intensity sweeten- ers are used, they don’t contribute to the product volume(s). Compensations must be made to achieve similarity to regular products. Bulking agents are often used to accomplish this purpose. Nonen- zymatic browning (Maillard reaction) is also not accomplished when high intensity sweeteners are used, and this must be compensated for by the use of appropriate ingredients. Table 7.10 lists some of the problems involved in reduced sugar and sugarless

baking, considerations in the balance of the formula- tion, and possible solutions in the development of new formulations.

CONCLUSION As mentioned earlier, sweeteners are an important ingredient in bakery products. There are many kinds of sugars and syrups and high intensity sweeteners available. Their usage depends on the kind of prod- uct to be manufactured. However, sugars and syrups provide characteristics typical of the product. When the sugar usage is reduced or replaced completely, similar products can be produced with the aid of bulking agents. Functional considerations on the use of sweeteners are described, and possible problems that may occur when sweeteners are reduced or replaced completely are identified. With the trend toward producing lower calorie products, use of high intensity sweeteners will increase in the future, but their use will not replace the traditional sugars and syrups completely.

ACKNOWLEDGMENTS The author thanks Dr. Joannie Dobbs, Department of Human Nutrition, Food and Animal Sciences, University of Hawaii-Manoa, Honolulu, HI, and Dr. Juscelino Tovar, Instituto de Ciencias y Technologia de Alimentos, Univerisdad Central de Venezuela, Paseo Los Ilustres, Urb. Valle Abajo, Caracas 1020- A, Venezuela, for their comments on the manu- script.

Tabl

e 7.

7. U

se F

requ

ency

of S

wee

tene

rs in

Cra

cker

s (n

) in

Hon

olul

u S

uper

mar

ket i

n Ju

ne 2

004

Salt

ine

Sod

a G

raha

m

Wat

er

Whe

at

Rye

W

heat

Sa

loon

C

lub

Savo

ry

Swee

tene

rs

Cra

cker

C

rack

er

Cra

cker

C

rack

er

Cra

cker

C

rack

er

Thi

ns

Pilo

t C

rack

er

Cra

cker

C

rack

er

Hig

h fr

ucto

se c

orn

411 1

41

5 71

8 11

1 11

12 1

Sucr

ose

or li

quid

21

1 1

315

416

718

212

111

1112

1

syru

p

sucr

ose

Dex

tros

e 31

1 1"

412

1 B

row

n su

gar

315

Cor

n sy

rup

soli

ds

411 1

31

8 11

1 11

2 1

Inve

rt s

ugar

or

115

218

212

Hon

ey

415

118

Whe

y po

wde

r or

11

1 1

316

112

512 1

syru

p

Mol

asse

s 21

5 11

6 31

8

lact

ose

Not

e: N

umbe

r ind

icat

es u

sage

ratio

(fr

eque

ncyi

n) in

sam

ples

surv

eyed

. "I

nclu

des

usag

e of

< 1

or

2%.

Non

e 41

1 1

212

212

218

512 1

Table 7.8. Functionality of Sugar and Syrup Sweeteners in Baked Goods

Table 7.9. Functional Considerations of Sweetener Systems in Baked Goods

Baked Goods Category Functions

Bread

Cakes

Cookies

Crackers

Supply fermentable solids Form color compounds in the crust

due to Maillard reaction Generate fivor and aroma Improve crumb texture and softness Extend shelf life by the

hygroscopicity

Provide sweetness Affect cake structure formation Improve crumb texture and crumb

tenderness Extend freshness by aiding moisture

retention and decreasing water activity of the product

Promote a good crust color

Generate fivor Affect cookie spread Control crispiness Control surface characteristics

Reduce the amount of water used in the dough

Supply fermentable solids if fermentation process is involved

Contribute fivor to the final product Contribute color to the final product

due to Maillard reaction in the baking process

Source:Adapted fromKulp et al. 1991.

Category Items to be Considered

Appearance

Mouthfeel and texture

Flavor

Marketing and regulator issues

Storage and handling

Process and preparation

Reactivity

Gloss Crystallinity

Frostings Crystallinity Tackiness Tenderness

Aroma

Legal appeal Ingredient label position Regulatory restrictions Health implications Calorie content Digestive effects Serum glucose value Cariogenicity

Crystallization (syrups and

Hygroscopicity (dry mixes) Bulking properties (dry mixes) Flowability (dry mixing) Pumpability (wet mixing) Dusting potential (dry mixes)

Solubility Consumer clean-up

Heat stability Fermentability Preservative qualities

liquid sweeteners)

Source:Adapted from Best 1992.

Table 7.10. Problems and Possible Solutions in Reduced Sugar or Sugarless Baking

Categow Items

Problems Loss of viscosity and body due to low solids. Poor aeration and cell structure. Poor heat transfer and ability to bake at temperatures necessary for browning. Loss of shelf life due to osmotic and water activity effects. Poor fivor release. Unfavorable shifts in glass-transition temperatures of proteins and starches.

Formulation Nutrition labeling guidelines. balance Physicochemical functions.

Quantifiable multicomponent interactions. Optimization of existing formulations with reduced sugar content-

usually a reduction of 1 5 2 0 % can be achieved without difficulty. Reduction of 80% sugar or more is very challenging-usually use of bulking agent(s)

is needed to product acceptable products.

New formulation development

Source: Adapted from Shukla 1995.

157

158 Part 11: Major Baking Ingredients

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