An offense is not deemed to be committed under this chapter, in the following cases:
(1) Where the order calls for an article of food or drug inferior to the standard required under this chapter and the difference is made known at the time;
(2) Where the article of food or drug is mixed with any matter or ingredient not injurious to health and not intended fraudulently to increase its bulk, weight or measure or conceal its inferior quality, if at the time such article is delivered to the purchaser it is made known to the purchaser that the article of food or drug is so mixed.