In both types of tortilla production, pneumatic transfer via both pressure and vacuum is used as a method of delivery of the raw ingredients to the cookers and mixers. Volumetric screw feeders are used to accurately dose the lime to the nixtamalization process. Since tortillas are rapidly becoming a mainstream staple they are often fortified. In this case screw feeders are used for the dosing of vitamins (iron, zinc, thiamin, riboflavin, niacin and folic acid) to the corn and wheat flour tortilla premixes. In this application example we will examine the details of the corn tortilla process. However, it should be noted that the same principles of conveying and feeding are applied in the wheat flour tortilla process.