{{Unreferenced, date=November 2011 The Falling Number (FN), also referred to as the Hagberg number or Hagberg–Perten number, is the internationally standardized (ICC 107/1, ISO 3093-2004, AACC 56-81B) and most popular method for determining sprout damage. With the Falling Number test, so-called weather or sprout damaged

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeolog ...

rye Rye (''Secale cereale'') is a grass grown extensively as a grain, a cover crop and a forage crop. It is a member of the wheat tribe ( Triticeae) and is closely related to both wheat (''Triticum'') and barley (genus ''Hordeum''). Rye grain is ...

, which adversely affects bread-making quality, could be detected at the grain

silo A silo (from the Greek σιρός – ''siros'', "pit for holding grain") is a structure for storing bulk materials. Silos are used in agriculture to store fermented feed known as silage, not to be confused with a grain bin, which is used ...

intake within a few minutes. Sprouting or pre-harvest

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

is caused by damp or rainy weather conditions during the final stage of maturation of the crop. The germination causes an accelerated production of the starch-degrading

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

alpha-amylase α-Amylase is an enzyme (EC 3.2.1.1; systematic name 4-α-D-glucan glucanohydrolase) that hydrolyses α bonds of large, α-linked polysaccharides, such as starch and glycogen, yielding shorter chains thereof, dextrins, and maltose: :Endohyd ...

. Severely sprouted grain kernels can contain several thousand times the amount of enzyme of sound un-sprouted kernels. Because of this, very low levels of severely sprouted kernels mixed into sound wheat can cause the entire lot to exhibit significant amylase activity. Since its introduction in the early 1960s, the FN test has become a world standard in the grain and flour milling industries for measuring alpha-amylase activity in wheat,

durum wheat Durum wheat (), also called pasta wheat or macaroni wheat (''Triticum durum'' or ''Triticum turgidum'' subsp. ''durum''), is a tetraploid species of wheat. It is the second most cultivated species of wheat after common wheat, although it represen ...

triticale Triticale (; × ''Triticosecale'') is a hybrid of wheat (''Triticum'') and rye (''Secale'') first bred in laboratories during the late 19th century in Scotland and Germany. Commercially available triticale is almost always a second-generation hy ...

, rye and

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley ...

, as well as milled products made from these grains.

History

The Falling Number method was developed at the end of the 1950s by Sven Hagberg and his co-worker Harald Perten, both at the Cereal Laboratory of the Swedish Institute for the Crafts and Industries.

Method description

The Falling Number method is uncomplicated, but requires an apparatus which follows the international standards. Such an apparatus consists of a water bath, a test tube, a stirring rod, and a stirring device. The test was performed manually when first employed, test instrumentation today is mostly automated. To analyze a grain sample it first needs to be ground to a powder; a flour sample can be analyzed as is. The sample is put into the test tube;

distilled water Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, dis ...

is added, and the tube is then shaken vigorously to achieve a homogeneous mix. The tube is then placed in the boiling water bath, and the operator begins to stir the sample. Simultaneously the starch begins to gelatinize and the

slurry A slurry is a mixture of denser solids suspended in liquid, usually water. The most common use of slurry is as a means of transporting solids or separating minerals, the liquid being a carrier that is pumped on a device such as a centrifugal p ...

becomes more

viscous The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

. The mixing ensures the gelatinization is homogeneous in the slurry, crucial for consistent test results. An additional effect of the high temperature is that the

enzyme contained in the grain begins to break the starch down into

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...

and

maltose } Maltose ( or ), also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the tw ...

, thereby reducing the viscosity of the slurry. The amount of starch break-down is directly proportionate to the alpha-amylase activity, meaning that the higher the activity of the alpha-amylase, the lower the viscosity will be. After 60 seconds of mixing, the stirrer is dropped from the top of the test tube, and the operator measures the time it takes for the stirrer to reach the bottom. That time, measured in seconds, is the Falling Number. When the stirrer is dropped, its speed and thus the time it takes for it to reach the bottom, will be determined by the viscosity of the slurry. In other words, the more sprouted the grain was, the higher the alpha-amylase activity will be. The higher the alpha-amylase activity the lower the viscosity of the slurry. The lower the viscosity of the slurry the faster the stirrer will fall to the bottom. That is why more sprouted grain results in a lower Falling Number as Falling Number is the time it takes the stirrer to fall to the bottom. The FN value has an inverse relationship with the alpha-amylase activity, meaning the higher the alpha-amylase activity the lower the FN value, and vice versa. Cereals Food technology Agricultural economics