Corn Grading Procedures and Standards Flashcards

Vocabulary flashcards covering grain definitions, numerical grade requirements, special grades, basis of determination, heating, and odor classifications from Chapter 4 of the Grain Inspection Handbook II.

Corn

Grain that consists of $50$ percent or more of whole kernels of shelled dent corn and/or shelled flint corn (Zea mays L.) and not more than $10.0$ percent of other grains for which standards have been established under the United States Grain Standards Act.

Whole Kernels

Kernels with three-fourths ($\frac{3}{4}$) or more of the kernel present.

Not Standardized Grain (NSG)

A sample designation given when grain does not meet the definition of corn and is not another grain for which standards have been established under the United States Grain Standards Act.

Classes of Corn

The three official market divisions of corn, consisting of Yellow corn, White corn, and Mixed corn.

U.S. Sample Grade Corn

Corn that does not meet requirements for numerical grades U.S. No. 1 through U.S. No. 5; contains stones with aggregate weight exceeding $0.1$ percent; contains $2$ or more pieces of glass, $3$ or more crotalaria seeds (Crotalaria spp.), $2$ or more castor beans (Ricinus communis L.), $4$ or more particles of unknown foreign or toxic substances, $8$ or more cockleburs (Xanthium spp.), or animal filth exceeding $0.20$ percent in $1000\text{ grams}$; has a musty, sour, or COFO odor; or is heating/distinctly low quality.

Flint Corn

A special grade of corn that consists of $95$ percent or more of Flint corn.

Flint and Dent Corn

A special grade of corn consisting of a mixture of Flint and Dent corn containing more than $5.0$ percent but less than $95$ percent of Flint corn.

Infested Corn

A special grade of corn that is infested with live weevils or other live insects injurious to stored grain.

Waxy Corn

A special grade of corn that consists of $95$ percent or more Waxy corn.

Optional Grade Designation

A grade designation commonly referred to as 'or better' (e.g., U.S. No. 2 or better) provided upon applicant request, which cannot be applied to a U.S. No. 1 designation.

Distinctly Low Quality

A quality determination made on the basis of the lot as a whole at the time of sampling when a condition exists that may or may not appear in the representative sample and/or the sample as a whole.

Commercially Objectionable Foreign Odors (COFO)

Odors foreign to grain that render it unfit for normal commercial usage, such as animal hides, decaying animal, fertilizer, fumigant, insecticide, oil products, skunk, smoke, strong weed, vegetable matter, or acrid insect odors.

Heating (HTG)

A condition in which corn develops a high temperature from excessive respiration, determined at the time of sampling or on the basis of the sample as a whole, requiring a grade of U.S. Sample Grade.

4-Hour Aeration Requirement

The procedure allowing a work portion or file sample containing lingering fumigant, insecticide, or fungicide odor to aerate in an open container for $4\text{ hours}$ or less to determine if the odor dissipates.

Factors Determined Before the Removal of BCFM

Determinations performed prior to removing broken corn and foreign material, including Distinctly Low Quality, Heating, Infested, Kind of Grain, Moisture, and Odor.

Factors Determined After the Removal of BCFM

Determinations performed after removing broken corn and foreign material, including Class, Damaged Kernels, Flint corn, Flint and Dent corn, Heat-Damaged Kernels, Odor, and Waxy corn.

U.S. No. 1 Grade Requirements for Corn

Standards requiring a minimum test weight of $56.0\text{ pounds}$ per bushel, maximum $0.1$ percent heat-damaged kernels, maximum $3.0$ percent total damaged kernels, and maximum $2.0$ percent broken corn and foreign material.

Mixed Corn Certification Requirement

The practice of recording the name and percent of each class in the mixture in the 'Results' section of the certificate to the nearest tenth percent ($0.1$ percent).