Invertase, or beta-fructofuranosidase, is an enzyme derived from yeast. It has the ability to break sucrose down into the simple sugars glucose and fructose. The resulting product, also known as inverted sugar syrup, is most often used in baking. It is commonly found in mass-produced candies because it is sweeter than some other forms of sugar and can increase the shelf life of sugary confections.
Honeybees can produce invertase, but for commercial use, creating large amounts of the enzyme is cheaper when made from yeast in large amounts. When invertase is added to sucrose, or common table sugar, the enzyme stimulates a process called hydrolysis. Hydrolysis splits the bond between glucose and fructose as it adds hydrogen and hydroxide, separating the two types of sugar.
Bakers and candy companies sometimes call inverted sugar syrup "invert syrup" or trimoline. They employ the product when baking because it has a stronger taste than normal sucrose, and the syrup will not crystallize as quickly as table sugar. In addition, inverted sugar tends to keep confections moist better than normal sugar can. The enzyme can, however, be considered a somewhat expensive ingredient; it requires a rigorous purification process. Thus, the cheaper enzyme glucose isomerase, which has the same effect on sucrose, is also commonly used in place of invertase.
Invertase may also be found in candies containing a liquefied sugar center, such as chocolate-covered cherries. Marshmallows and creams also tend to use the enzyme for texture or consistency as well as longevity. Even some cigarette companies use trace amounts of invertase or inverted sugar syrup in the lining of a cigarette to give it an attractive taste.
The enzyme is usually sold in three different strengths—single, double and triple. Some forms come as a liquid, while other types exist as a powder that can either be added directly to a mixture or combined with water first. The product is usually clear or takes on a pale yellow color and may smell slightly of fermentation. Though the enzyme is inclined to higher levels of activity at low temperatures, it is best when used at about 140 degrees Fahrenheit (60 degrees Celsius), because sucrose will split faster at higher temperatures.
Most manufacturers of the enzyme caution that, while the enzyme is not flammable, it is a chemical, and the use of gloves is recommended. Contact with eyes should be avoided. Those with certain allergies might experience a reaction to eating or even handling invertase.