Food adulteration may consist in:
1—Extraction of nutritive substances.
2—Addition of substances lowering the quality of the food.
3—Substituting inferior grades of food.
4—Fraudulent labeling of food.
5—Changing the appearance of food by coloring or other methods which will conceal the inferior quality.
6—Adding injurious substances for the purpose of preserving the food.
The Pure Food Act of 1906 makes the following classification in a statement of the methods which are considered in the adulteration of foods:
1—“If any substance has been mixed and packed with it so as to reduce or lower or injuriously affect its quality or strength.
2—“If any substance has been substituted, wholly or in part, for the article.