## 1 Introduction  
The Falling Number (FN) test, a widely used method for evaluating \(\alpha\)-amylase activity in flours of various cereals (mainly wheat and barley flours), has been performed for decades according to a more or less unchanged procedure [1]. It has been approved by all relevant international organizations, such as the International Organization for Standardization (ISO), the American Association of Cereal Chemists (AACC), the International Association for Cereal Science and Technology (ICC), the Association of Official Analytical Chemists (AOAC), and the American Society of Brewing Chemists (ASBC) [2; 3; 4; 5; 6]. This method is very simple, and it is based on the viscosity change of a hot flour paste and involves mixing 7 g of flour with 25 mL of water in a test tube, which is then immersed in a boiling water bath and mixed with the stirrer in an up-down direction for 55 s. During this time, rapid gelatinization of starch occurs. After mixing, the stirrer is released to drop to the bottom of the test tube. The total time of mixing and the time taken for the stirrer to \"fall\" to the bottom of the test tube is defined as FN and expressed in seconds. Increased \(\alpha\)-amylase activity leads to faster liquefaction of the paste, and thus, a shorter fall time, i.e., a smaller FN. The values of FN represent an indirect measure of \(\alpha\)-amylase activity and they are inversely proportional [2; 7; 8]. The FN test is recognized worldwide because of its simplicity and the relatively short duration of the procedure. It is now considered the standard method for evaluating grain quality in the context of the market and trade in grain, as well as for evaluating flour and adjusting flour blends for bakery production. The FN test is very successful in detecting increased levels of \(\alpha\)-amylase in mature grains caused by preharvest sprouting (PHS) or late maturity amylase (LMA) [9; 10; 11; 12]. Wheat grains with FN values below 250 s are considered inferior grains and usually fetch a lower price in trade [2; 13]. However, these increased levels of \(\alpha\)-amylase induced by PHS and LMA are still relatively low compared to the levels of \(\alpha\)-amylase in malted grain. The FN test is not suitable for the determination of \(\alpha\)-amylase activity in malt flour because the amyloid activity is too high to be determined with the FN instrument. This is because the liquefaction of the hot starch paste in malt flour samples is very intense and the viscosity decreases so much that the stirrer of the FN instrument immediately falls through the liquid starch paste and the instrument records a value of 61 s. This is the time required for the stirrer to mix the flour-water suspension and freely fall through the completely liquefied paste [14]. According to some previous studies, the FN value of 61 s corresponds to \(\alpha\)-amylase activity of about 5 Ceralpha Units per gram (CU/g), and this is the maximum \(\alpha\)-amylase activity of flour that can be measured by the standard FN method [15]. Considering that the activity in malt flour is much higher and can exceed 300 CU/g, depending on the length of germination period in the malting process and the origin of the malt [15; 16; 17], it is clear that the standard method for determining FN cannot be used for malt flour samples. For this reason, several other methods are used to determine amyloid activity in malt flour. Determination of the total amyloid activity in malt and malt flour is usually carried out by the method of determination of diastatic power. Diastolic power is influenced by all amyloid enzymes present (\(\alpha\)- and \(\beta\)-amylase, limit dextrinase, and \(\alpha\)-glucosidase), but mainly by \(\beta\)-amylase [18; 19].