Legislation and types of syrup
According to the current legislation, glucose syrup is a purified and concentrated aqueous solution of food carbohydrates, obtained from starch, starch and / or inulin, which must have the following characteristics:
a) dry matter not less than 70% by weight
b) dextrose equivalent not less than 20% by weight on the dry substance, expressed in D-glucose
c) sulphated ash not exceeding 1% by weight on the dry substance.
The dextrose equivalent (better known as dextrose equivalence) is an estimate of the percentage of reducing sugars present in glucose syrup.
The definition of glucose syrup is quite broad, so this name is attributable to products with slightly different characteristics. As anticipated, these syrups are obtained from various types of starch (generally from corn) through an enzymatic conversion process; starch, in fact, is a polysaccharide consisting of many glucose units linked together in a linear and branched manner. At the industrial level, enzymes capable of dissolving these bonds are added, giving rise to much shorter glucose chains (maltose, dextrins) and single sugar units. Among these enzymes we remember alpha amylase, which allows to obtain syrups with a content of about 10-20% of free glucose, and gluco-amylase, which increases this percentage over 90%. Alpha-amylase is produced industrially using a bacterial species ( Bacillus sp.), While gluco-amylase uses a fungal species: Aspergillus.
As shown in the table, based on dextrose equivalence, glucose syrup can assume characteristics suitable for particular food uses.
Uses in the food industry
Glucose syrup comes in the form of a dense, colorless syrup with a sweet taste. Despite being less sweet than sugar (in soft drinks it is preferred to take advantage of the greater sweetening power and greater solubility of fructose syrup), it presents a whole series of technological advantages. Glucose syrup is in fact able to prevent lactose crystallization, lower the freezing point and give body to the finished product. As such, it is indicated in numerous applications in the ice cream field, to control the degree of sweetness and the freezing point, and in the confectionery / pastry (croissants, biscuits, panettone, doves etc.), where the creaminess of the product is increased while maintaining a low degree of sweetness or lowering its sweetening power (for example due to the presence of important quantities of too much sugary fruit). Glucose syrup is also appreciated for its preservative properties.
Nutritional Properties
From a nutritional point of view, glucose syrup is a typical example of a food rich in "empty calories", a term used to indicate its high energy power as opposed to the absence of vitamins, proteins, fats and fiber, with a very low content of mineral salts. Depending on the dextrose equivalence, glucose syrup may exhibit a more or less high glycemic index (GI) (if DE is high, even IG is high, and vice versa). It is no coincidence, therefore, that the extensive use of glucose - fructose syrups in the food sector is considered an important person responsible for the spread of obesity.
Even when obtained from wheat starch, glucose syrup does not create major problems for celiac, because it is purified by the protein component, therefore substantially gluten-free.
