Malt flour is obtained from grain (barley, wheat, rye or spelt). Here, the grain is brought to germination under defined conditions (moistness, temperature and time). During the germination process, enzymes, mainly amylases, proteases and cellulases, are formed and the insoluble reserve substances of the grain changed into soluble compounds. After several days, the germination process is halted and the green malt obtained is dried. The ready malt contains a great number of natural colour and flavouring substances and, depending on the process, is enzyme active or enzyme inactive.
By the use of malt flours and malt extracts, baked goods properties, such as crust colour, crumb colour, aroma and taste as well as volume of the baked goods and freshkeeping, can be improved.
The reducing sugars contained in the malt extract are an important partner of the Maillard reaction (non-enzymatic colouring reaction) in baked goods. By the effect of heat, the sugar substances react with amino acids while forming the characteristic Maillard products, which significantly influence the aroma, taste, crust colouring and crispness in a positive way.
In the case of malt flours and malt extracts, a difference is made between enzyme active and enzyme inactive malt products. Decisive is a specific temperature control during the kiln-drying process (malt flour) or during vacuum steaming (malt extract). The different effects are described briefly in the following.
Malt extract is an additional refinement of malt. The malt kernels are ground, mashed and processed for several hours at 50 – 70° C. During this time, insoluble malt ingredients are decomposed enzymatically into soluble sugar substances such as maltose (malt sugar). Subsequently, this is filtered and, with the help of vacuum steaming and a specific temperature, the desired content of solids set. Malt extract stands out due to a high percentage of reducing sugars, among other things.
The details in table 4.1 are in relation to light-coloured malt flours and light-coloured malt extracts and are to be viewed as orientation values.