Sugars having various useful properties have been manufactured by the use of enzymes.
1. Glucose
Glucose is manufactured by liquefaction of starch with α-amylase ( KLEISTASE L1, T10S ) followed by treatment with pullulanase ( Pullulanase "Amano" 3, KLEISTASE PL45 ) and glucoamylase ( Gluczyme AF6 ). Its sweetness is about 60% that of sugar, and it has a reducing property. It is used not only as a sweetener for foods e.g. drinks and cakes but also as an energy source for transfusions, and as a raw material for the chemical industry e.g production of sorbitol, amino acids.
2. Maltose
Maltose is manufactured by liquefaction of starch followed by
treatment with pullulanase ( Pullulanase "Amano", KLEISTASE PL45 ) and β-amylase. Its sweetness is about
40% that of sugar and its molecular weight is the same as that
of sugar, hence maltose is used as a light sweetener in place
of sugar for Japanese cakes. It is also used for transfusion because
maltose can be an energy source not requiring insulin. Another
use for maltose is as an ingredient of Maltitol.
3. Maltotriose
Maltotriose is produced by liquefaction of starch followed by treatment with maltotriose-producing amylase ( AMT 1.2L ) and pullulanase ( Pullulanase "Amano" 3, KLEISTASE PL45 ). Its sweetness is about 30% that of sugar. Maltotriose is characterized by its non-crystalline form and strong water-preservative property, and thus has a starch anti-staling effect. With these properties, it is often used for Japanese cakes that must maintain a certain percentage of moisture.
4. Branched oligosaccharide (Isomalto oligosaccharide)
Branched oligosaccharide is an oligosaccharide containing a series of α-1,6 bonds in its structure. It is produced by liquefaction of starch followed by treatment with β-amylase, pullulanase ( Pullulanase "Amano" 3, KLEISTASE PL45 ), and transglucosidase ( Transglucosidase L "Amano" ). Its sweetness is about 40% that of sugar, and it is easily utilized by intestinal bacteria but not by bacteria in the mouth, so it does not promote dental caries.
5. Cyclodextrin
Cyclodextrin is a nonreducing cyclic dextrin produced from starch by treatment with cyclodextrin glucanotransferase ( Cyclodextrin glucanotransferase "Amano" ). There are several types such as α-cyclodextrin (glucose number: 6, α-CD), β-cyclodextrin (glucose number: 7, β-CD), and γ-cyclodextrin (glucose number: 8, γ-CD). The hollow portion of the molecule is hydrophobic, thus it has the property of enclosing various compounds. With this property cyclodextrin is used for stabilization of various materials, preservation of aroma, masking bitter tastes, and increasing solubility of slightly soluble materials.
6. Isomerized sugar
Isomerized sugar is a mixture of glucose and fructose. There are 2 types of liquid sugar; glucose-fructose liquid sugar whose fructose content is more than 42% (available by treatment of glucose with glucose isomerase) and fructose-glucose liquid sugar whose fructose content is more than 55% (available by addition of high-fructose fraction obtained by separation of the above-mentioned type of liquid sugar with ion-exchange resin). They are inexpensive and their sweetness is almost equivalent to that of sugar; thus they are used as a sweetener to replace sugar in beverages and ice cream, for instance.
7. Fructose
Fructose is manufactured by its separation from isomerized sugar by the use of ion-exchange resin. Fructose used to be manufactured by acidic decomposition of an artichoke, but with the change of manufacturing method, it has become inexpensive and usable in the food industry too. Its sweetness is higher than that of sugar at cold temperature, but decreases at higher temperatures. For its strong browning at heating, fructose is mainly used for ice cream. Fructose is used to sweeten some diet foods and is also used in sports drinks.
