VII. TESTING ANALYSIS METHODS
The sorghum samples (each about 2500 grams) were sent directly from the local grain elevators to the Cereal Quality Lab (CQL) in the Department of Soil and Crop Sciences, Texas A&M, College Station, Texas. Upon arrival, the samples were dried, if needed, to a suitable moisture content to prevent any subsequent deterioration during the testing period. The samples were then split into two 1100 to 1250-gram subsamples using a Boerner divider. The divider splits the complete sample into two while keeping the attributes of the grain sample evenly distributed between the two subsamples. One subsample was shipped to Amarillo Grain Exchange (AGE) in Amarillo, Texas for grading and mycotoxin testing. AGE is an official grain inspection service provider in Texas as designated by USDA’s Federal Grain Inspection Service (FGIS). The grade testing procedures were in accordance with FGIS’s Grain Inspection Handbook and are described in the following section. The other subsample was analyzed at CQL for chemical composition and other physical factors following either industry norms or well-established procedures in practice for many years.
A. Sorghum Grading Factors
1. Test Weight
Test weight is a measure of the quantity of grain required to fill a specific volume (Winchester bushel). Test weight is a part of the FGIS Official U.S. Standards for Sorghum grading criteria.
The test involves filling a test cup of known volume through a funnel held at a specific height above the test cup to the point where grain begins to pour over the sides of the test cup. A strike-off stick is used to level the grain in the test cup, and the grain remaining in the cup is weighed. The weight is then converted to and reported in the traditional U.S. unit, pounds per bushel (lb/bu).
2. Broken Kernels and Foreign Material (BNFM)/Foreign Material
Broken kernels and foreign material (BNFM) and foreign material are part of the FGIS Official U.S. Standards for Sorghum.
This test determines the amount of broken kernels and foreign material contained in the sample. Broken kernels is defined as all material which passes through a 5/64 th inch triangular-hole sieve and over a 2.5/64 th inch roundhole sieve. Foreign material is defined as all material, except sorghum, that remains on top of the 5/64th inch triangular-hole sieve and all matter other than sorghum which passes over the number 6 riddle. Foreign material is reported as a sum of the mechanically separated foreign material as a percent of the dockage-free sample weight and the handpicked foreign material as a percent of the handpicked sample portion weight. BNFM is reported as the sum of broken kernels as a percent of the dockage-free sample weight and the foreign material.
3. Total Damage/Heat Damage
Total damage is part of the FGIS Official U.S. Standards for Sorghum grading criteria.
A representative working sample of 15 grams of BNFM-free sorghum is visually examined by a properly trained individual for content of damaged kernels. Types of damage include germ-damaged kernels, ground- and/or weather-damaged kernels, diseased kernels, frost-damaged kernels, heat-damaged kernels, insect-bored kernels, mold-damaged kernels (surface and/or internal), mold-like substance, purple-pigment-damaged kernels, and sprout-damaged kernels. Total damage is reported as the weight percentage of the working sample that is total damaged grain.
Heat damage is a subset of total damage and consists of kernels and pieces of sorghum kernels that are materially discolored and damaged by heat. Heat-damaged kernels are determined by a properly trained individual visually inspecting a 15-gram sample of BNFM-free sorghum. Heat damage, if found, is reported separately from total damage.