Food adulteration is the process in which the quality of food is lowered either by the addition of inferior quality material or by extraction of valuable ingredient. ... A food item is said to be adulterated if: A substance which is added is injurious for human consumption.Food adulteration is the process in which the quality of food is lowered either by the addition of inferior quality material or by extraction of valuable ingredient. ... A food item is said to be adulterated if: A substance which is added is injurious for human consumption.