BS 3rd Year 2015 (Morning Program)
Department of Food Science & Technology
University of Karachi
Also referred to as the Hagberg’s Number.
Measures the level of alpha-amylase activity that has
occurred within a grain sample.
It is an enzyme that degrades starch within the seed
greatly reducing flour quality.
1960 Sven Hagberg developed a rapid, original method for
determining alpha-amylase activity in sprout damaged grain.
1961 Sven Hagberg named the method “Falling number” with a
1962 Harald Perten founded Perten Instruments and commercialized
falling number apparatus.
1968 International Association of Cereal Science and Technology
approved the method as ICC Standard No. 107/1
1972 The method was implemented as an official AACC method 56-
1982 The International Organization for Standardization approved the
method as ISO 3093.
The Falling Number
How is FN calculated?
Falling Number= (5sec stand) + (55 sec stirring )+ (time taken to fall in sec)
Example: 5 + 55 + 240 = 300FN
When tubes are in water bath, starch begins to gelatinize and the
slurry becomes viscous.
The alpha-amylase enzyme starts to breakdown starch and the
viscosity thus decreases.
The amount of starch break down dependent on alpha-amylase
activity which means the higher the activity of amylase the lower is the
The more sprouted the grain, the higher the alpha-amylase activity.
The higher the alpha-amylase activity, the lower the viscosity of slurry.
The lower the viscosity of slurry the faster the stirrer will fall.
More sprouted grain results in low FN, as FN is the time it takes the
stirrer to fall to the bottom.
Chemistry behind FN
Why measure the alpha-amylase activity??
Rainy, adverse weather conditions during harvest can
cause sprouting. When sprouting occurs the alpha-
amylase enzyme develops. Alpha-amylase activity has
direct impact on bread, pasta quality and adversely
affects the malting process.
As little as 5% sprouted grain mixed with 95% sound
grain can render the entire mixture unacceptable.
Falling Number in Pasta and Noodle
Producing noodles from flour with a low falling
number is difficult with dough handling and cutting
problems and product sticking to machinery. It also
result in an off-color end consumer product which will
be sticky after it is boiled. Using flour with the correct
FN will result in saving through improved processing
as well as a higher quality end product.
A certain amount of alpha-amylase is necessary for proper baking to
occur. The alpha-amylase breaks down starch to provide sugar to help
fuel the fermentation process. The presence of enzyme depend upon the
quality of bread produced.
FN=250; When the alpha-amylase activity is right, a high volume
bread with firm and soft texture is achieved.
FN=62; If the activity is too high, a sticky bread crumb and low
volume may result.
FN=400; If the activity is too low, a dry bread crumb with diminished
volume may result.
The FN value has an inverse relationship with the alpha-amylase activity
meaning the higher the amylase activity the lower the FN value.
Temperature of water bath should be 100C
The FN instrument analyses viscosity by measuring the resistance of a
flour-and-water paste to a falling stirrer.
FN result are recorded as an index of enzyme of enzyme activity in a
wheat or flour sample and the result are expressed in time as seconds.
A high FN (above 300 sec) indicates minimal enzyme activity and
sound quality wheat or flour.
A low FN (below 250 sec) indicates substantial enzyme activity and
sprout damaged wheat or flour.
When grinding a wheat sample to perform a FN test, it should be at-
least 300gm to assure a representative sample.
Values below 300 sec are indicative of poor quality for milling and
Need to know!
Machine develop by a North American Company;
Related to Instrument
Late maturity a-amylase: Low falling number in wheat
in the absence of pre-harvest sprouting.
(Australia, 30 Jan 2007)
Late maturity and pre-harvest a-amylase.
Effect on a-amylase activity in wheat grain.
Effect of temperature on wheat grain.
Effect on end-product.