BookSCO_85011320245

abstract

• © 2015 AACC International, Inc. Published by Elsevier Inc. All rights reserved. Maize is the most-produced cereal worldwide, with a current annual production exceeding 1 billion metric tons. The nixtamalization process is one of the main direct food uses of this cereal grain. Selected white, yellow, and blue dent open-pollinated varieties or hybrid corns are processed into tortillas and alkaline-cooked snacks. The major advantages of growing hybrids are improved yields and more uniform kernel type and maturity. Genetics, environment, and postharvest practices of grain handling and storage affect the quality composition and physical properties of the kernel. The main criteria used to select corn for the manufacturing of tortillas and related snacks are related to their physical properties because these affect chemical composition, functionality, processing parameters, and end use. Table tortillas are preferably manufactured from dent white maize, although yellow kernels are also used or blended with white kernels before lime-cooking. Most industrial tortilla processors contract food-grade and non-genetically modified corns. The preferred corns should have a test weight of 76-78 kg/hL and a density of 1.3 g/cm3 and be medium to large sized (290-340 g/1,000 kernels). They should possess a round crown, a smooth dent, an intermediate endosperm texture, an easily removable pericarp, a clean bright white or yellow color, and a kernel with tolerance to damage during handling. In addition, kernels should be free of heat, insect, or mold damage. A high proportion of hard (vitreous) to soft (chalky) endosperm is required, but flinty is not desirable because flinty corns require higher cooking regimes, which demand more energy. These grain features are relevant because they are closely related to dry matter loss or tortilla yield, processability, and end-product quality.