What are the national standards for corn? A detailed interpretation of the main contents

The national standard for corn (GB 1353-2018) was officially implemented on February 1, 2019, and divides corn into 5 grades. Among them, Grade 1 corn has a test weight greater than or equal to 720g/l, an imperfect kernel content less than or equal to 4.0%, a moldy kernel content less than or equal to 2.0%, an impurity content less than or equal to 1.0%, a moisture content less than or equal to 14.0%, and normal color and odor.

Grade 1 corn: test weight ≥720g/l, imperfect kernel content ≤4.0%, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.

Grade 2 corn: test weight >720g/l ≥690g/l, imperfect kernel content ≤6.0%, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.

Grade 3 corn: test weight >690g/l ≥660g/l, imperfect kernel content ≤8.0%, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.

Grade 4 corn: test weight >660g/l ≥630g/l, imperfect kernel content ≤10.0%, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.

Grade 5 corn: test weight >630g/l ≥660g/l, imperfect kernel content ≤15.0%, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.

Below standard: test weight <660g/l, no requirement for imperfect kernel content, moldy kernel content ≤2.0%, impurity content ≤1.0%, moisture content ≤14.0%, normal color and odor.