Very serious damage means any defect, other than color, which very seriously affects the appearance, or the edible or shipping quality of the individual portion of kernel or of the lot as a whole. Any one of the following defects or any combination of defects the seriousness of which exceeds the maximum allowed for any one defect shall be considered as very serious damage:

(a) Shriveling when more than 50 percent of the portion of kernel is severely shriveled;

(b) Mold when plainly visible on more than one-fourth of the surface of the portion of kernel in the aggregate;

(c) Discoloration of the meat when more than one-half the volume of the portion of kernel is severely discolored;

(d) Insect injury;

(e) Rancidity or decay; and,

(f) Shell, or any foreign material.