This method describes the determination of α-amylase in malt.
α-Amylase is primarily involved in the degradation of starch to dextrins, thereby causing liquefaction. Its activity in barley indicates the degree to which germination has occurred, and in malt, it helps predict the time required for iodine test to yield a negative result during mashing. For this reason, α-amylase is considered to be a characteristic indicative of the quality of malt. Microbial enzyme preparations can also be analyzed with reference to their α-amylase activity.
Malt intended for use in beer brewing or elsewhere in the food industry
The substrate for the limit dextrins is prepared by adding excess β-amylase to a standard solution of starch. An extract of malt is added, and the α-amylase present in the malt brings about the degradation of the limit dextrins. With the addition of an iodine solution, the time required for the standard color of the starch-iodine complex to be reached is known as a “dextrinizing unit” [1].