French to English Other Agriculture cocoa production

La qualité du cacao porte habituellement sur les critères physico-chimiques que sont **le grainage**, le taux de beurre, l’homogénéité des fèves mais aussi, et de plus en plus, la qualité sanitaire relative à la présence de contaminants chimiques dans les produits marchands.

I've found plenty of info on the criteria used to select cocoa beans, such as this:

http://unctad.org/infocomm/anglais/cocoa/quality.htm

"The International Cocoa Standards require cocoa of merchantable quality to be fermented, thoroughly dry, free from smoky beans, free from abnormal or foreign odors and free from any evidence of adulteration. It must be reasonably free from living insects, broken beans, fragments and pieces of shell and foreign matter and reasonably uniform in size.

Throughout the world the standards against which all cocoa is measured are those of Ghana cocoa. Cocoa is graded on the basis of the count of defective beans in the cut test. Defective beans should not exceed the following limits:

Grade I
v Mouldy beans, maximum 3% by count;
v Slaty beans, maximum 3% by count;
v Insect-damaged, germinated or flat beans, total maximum 3% by count.

Grade II
v Mouldy beans, maximum 4% by count;
v Slaty beans, maximum 8% by count;
v Insect-damaged, germinated or flat beans, total maximum 6% by count."

But still none the wiser as to what "grainage" is referring to.

MTIA