There are two ways of avoiding or retarding this process. Sorbitol syrup has the property of binding water and can be substituted for part of the sucrose or glucose content. The other method relies on the action of invertase, an enzyme, which gradually converts sucrose into invert sugar (equal parts of glucose and fructose) - a form of sugar which does not readily crystallise and is also hygroscopic and moreover also tends to impart this property to its environment. Invertin 4738 is such a product.
As the action of Invertin is gradual, products to which it has been added can be worked while they are still firm or plastic, becoming soft only gradually as the enzyme action proceeds during storage. The enzymic splitting of sucrose can only work if water - which is chemically converted in the reaction - is present; about 5% by weight of the sucrose to be split being needed.
Invertin 4738 is a sweetish, nearly clear, light yellow, viscous liquid with a slightly yeasty smell. Its active component is the enzyme Beta-Fructosidase (derived from yeast cells) carried in Glycerol, and its enzymicactivity (as measured by the Weidenhagen method) is always constant. In storage, its container must be kept sealed and it should be kept cool (or preferably refrigerated), when its shelf-life will be at least 12 months.
Enzymes, consisting of digestible proteins (i.e. foodstuffs) are not normally considered to be “additives”, and do not therefore require special approval. The carrier Glycerol (E422) is generally approved by Food Laws in unlimited quantities. Invertin 4738 also meets applicable purity requirements, and its microbiological quality is checked in accordance with relevant FAO-WHO recommendations.
The usual Invertin dose is 80-125ml per 100kg of composition. It is extremely important that the enzyme is uniformly distributed - best achieved by first premixing it with a small quantity of composition, which is then gradually and thoroughly worked into a bulk. Since the enzyme (unlike Sorbitol) is destroyed by temperature above 65°C, it can only be added to products requiring boiling after they have cooled. It is similarly de-activated by an excess of alcohol, and can therefore not be used in mixes containing more than 20% (vol) of this.
The rate of inversion can be accelerated by adjusting the pH to 4.5 - 5.5; for example by adding to a neutral (pH7) mix about 2ml of 50% citric acid solution per 10kg of composition - provided, of course, that this is not objectionable on flavour grounds. Where flavour considerations prevent the use of citric acid, the amount of Invertin can be increased instead.
Invertin is particularly beneficial for (and widely used in) marzipan products. To protect these from fermentation, yeasts and moulds when not stored under ideal conditions, the addition of a small amount of Sorbic Acid (1.5g per kg), uniformly distributed through the mix, is strongly recommended.
Sometimes, a viscous, opaque fondant cream (or near-solid fondant) has to be used to fill chocolate hollows so that these can be closed with couverture without difficulty but it is usually desirable that the centre should subsequently become a clear liquid. This can be achieved with the aid of Invertin added to the composition shortly before filling and after the temperature has dropped below 65°C, but preferably before the addition of alcohol, and at a rate of between 150 and 250ml of Invertin per 100kg of composition.
Whilst it is hardly ever necessary to change recipes if Invertin is used, it is advisable to enrobe or coat finished products as soon as possible.
The above information is given in good faith, and in the light of current knowledge, but without obligation or responsibility on our part. Producers are recommended to carry out their own tests and assure conformity with any regulations etc. that may be relevant from time to time.
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