What Is The Falling Number Test?

    Since the rain in August, HRSW quality has suffered and the "falling numbers test" is being performed to determine crop quality.  This test is being used in HRSW due to the large amount of acres affected by rains across North Dakota
    The falling number test helps to determine the extent of sprout damage that occurred in a given sample.  The test is rather simple.  The falling number is a measure of the time required for a plunger to fall through a slurry made from a specified amount of flour and a specified volume of water.  This slurry is maintained at a temperature favorable for enzyme (alpha-amylase) activity.  The time in seconds that is required for the plunger to fall through the slurry is the unit of measurement.  The lower the falling number, the greater alpha-amylase activity, and the greater the sprout damage.  Sprouting, the germination process, can affect the inside composition of a kernel even though the exterior of the kernel appears sound. Alpha-amylase levels may be considerably elevated and will be detected by a falling number test.  Generally speaking, falling numbers above 300 indicate no sprout damage; falling numbers between 200 and 300 indicate some sprouting; and falling numbers below 200 indicate severe sprout damage.
    Sprouting causes a degradation of the starch and protein in the wheat endosperm and results in flour or semolina that produces inferior quality products.  Sprout damaged flour in HRSW results in dough stickiness or bread loaves with gummy insides, large voids due to reduced gluten strength and less water absorption during dough preparation, resulting in decreased bread yield.  Sprouting in durum results in increased cooking loss, softer cooked spaghetti, increased speck count and decreased spaghetti shelf stability.  
    The European countries and Japan are very concerned about falling numbers due to the their baking methods.  In European countries, many of the domestic wheats already have high alpha-amylase activity and the addition of sprouted wheat merely serves to compound the problem.  In Japan, barley malt, which is a source of the enzyme alpha-amylase, is not added to the flour during milling as is done in the United States,  therefore, they are much more conscious of the level of sprouting in the wheat that they purchase.
    The falling number test has been around since the early 1970's but has been largely associated with durum and pasta processing.  With the unfavorable weather conditions that affected our wheat crop, quality factors once again have caused major discounts at times of poor prices.  How the milling industry will handle the large amount of this grain is yet to be determined.

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