20 Glucose/Dextrose
The sugar known as glucose has two origins:
- In a natural form in most fruits
- In a processed form from corn (corn syrup)
In baking, we usually refer to industrially made glucose. It is made from corn and the resulting product, a thick syrup, is then adjusted to a uniform viscosity or consistency. The particular form of the syrup is defined by what is known as the dextrose equivalent, or DE for short. Corn syrup is the most familiar form of glucose.
In plant baking, high-fructose corn syrup (HFCS) is the major sweetening agent in bread and buns. It consists of roughly half fructose and half dextrose. Dextrose (chemically identical to glucose) is available in crystalline form and has certain advantages over sucrose:
- It is easily fermentable.
- It contributes to browning in bread and bun making.
- In crystalline form, it is often used in doughnut sugars as it is more inclined to stay dry and non-greasy.
- It is hygroscopic and valued as a moisture-retaining ingredient.
- It retards crystallization in syrups, candies, and fondant.
Corn syrup is made from the starch of maize (corn) and contains varying amounts of glucose and maltose, depending on the processing methods. Corn syrup is used in foods to soften texture, add volume, prevent crystallization of sugar, and enhance flavour.
Table 3, above, showed that glucose/dextrose has a sweetening level of approximately three-quarters that of sugar. Table 4 shows the amount of corn syrup or HFCS needed to replace sugar in a formula.
| Type of Sugar | Solids | Replacement Factor |
| Granulated sugar | 100% | 1.0 |
| Regular corn syrup | 80% | 1.25 |
| High-fructose corn syrup | 71% | 1.41 |
Table 4 Replacement factor for Corn Syrup and High-Fructose Corn Syrup
Glucose, HFCS, and corn syrup are not appropriate substitutions for sucrose in all bakery products. Certain types of cakes, such as white layer cakes, will brown too much if glucose or HFCS is used in place of sugar.