(a) Samples of product may be taken from any lot of product which is submitted for inspection or grading and packaging with official identification, or sample may be taken after packaging for the purpose of determining in accordance with provisions of this part if such product possesses satisfactory keeping quality.

(b) Samples of product may be taken for keeping quality tests in accordance with provisions of this part from any lot of product submitted for inspection or grading. Issuance of the inspection or grading certificate may be withheld pending completion of the tests.