Factors Affecting the Alkaline Cooking Performance of Selected Corn and Sorghum Hybrids

Abstract

Cereal Chern. 87(6):524-531Dent com (Zea mays L.) and sorghum (Sorghum hieolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for alkaline cooking performance. The influence of kernel characteristics including hardness, density, starch properties (thermal. pasting, and crystallinity). starch content. protein content. and prolamin content on alkaline cooking performance was also determined. Com nix tarnal moisture content was lower for hard, dense kernels with high protein contents; sorghum nix tarnal moisture content was lower for kernels with low moisture contents and low starch relative A major food use of corn (Zea Mays L.) and sorghum (Sorghum bicolor L. Moench) grain (kernel) is commercial production of tortillas, snack chips, and related foods through the alkaline cooking process known as nixtamalization (Serna-Saldivar et al 1988;Suhendro et al 1998;Taylor et al 2006). During nixtamalization, grain is cooked in a lime solution, allowed to steep for 12-16 hr. washed to remove loose pericarp, and stone-ground to produce masa (corn or sorghum dough) (Sahai et al 1999). Masa is then formed and cooked into desired end products.Nixtamalization efficiencies are of primary concern to processors and depend on three factors: 1) optimizing degree of cook; 2) optimizing pericarp removal; and 3) minimizing dry matter loss (DML) (Shandera et al 1997). During nixtamalization, thermal transfer due to hydration results in partial gelatinization of starch, limited granule swelling, and disruption of starch crystalline structure (Mondragon et aI2004). Degree of cook is determined by the rate at which kernels absorb moisture and it affects masa texture and final product quality (Sahai et al 1999). Slower moisture absorption, which is associated with harder kernels, assures product consistency (Shandera et al 1997). Pericarp removal is the primary purpose of the washing step. Pericarp in masa foods can have an adverse affect on texture, color. and processing properties (Serna-Saldivar et al 1991). However, complete removal of pericarp is not always desirable due to decreased product yield. Grain solids loss during cooking. steeping, and washing increases waste water disposal costs and decreases end product yield (Sahai et al 2000). While these factors are primarily influenced by processing conditions, grain characteristics such as hardness, kernel composition, and starch properties are also critical (Sahai et aI2001a).Corn and sorghum contain areas of both vitreous and opaquesoft endosperm. The vitreous endosperm is made up of polygonalshaped starch granules tightly packed in a continuous protein matrix with dispersed protein bodies (Hoseney 1994). The opaque endosperm is made up of spherical starch granules loosely packed in a discontinuous protein matrix with no protein bodies (Hoseney 1994). While vitreousness is not synonymous with hardness, increased amounts of matrix protein and protein bodies have been associated with hardness (Chandrashekar and Maz...

Effect of Sprouting on Amino Acids, Protein Solubility and Availability in Green and White Faba Bean (<em>Vicia faba</em> L.)

“…Protein content were 8.72, 10.54% in raw green and white faba bean, respectively. These results are in agreement with Johnson et al (2010) who found that crude protein content in whole faba bean grain is ranged from 7 to 15% or 10.30 to 14.90%.…”

Environment and Hybrid Influences on Rapid‐Visco‐Analysis Flour Properties of Food‐Grade Grain Sorghum

“…In a companion study, the environment was found to have the largest effect on variation in grain yield, kernel mass, kernel density, and kernel composition; the hybrid to have an intermediate effect; and the environment‐by‐hybrid interaction to have minor importance, accounting for less than 2% of the total variation (Griess et al, 2010). This research indicated that dryland production environments with a nonlimiting N supply produced dense sorghum kernels with high protein and low starch concentrations, as also reported by Johnson et al (2010), Taylor et al (1997), and Kaye et al (2007), whereas irrigated production environments produced softer grain. Asgrow Orbit and ICRISAT Macia produced the densest kernels with high protein and low starch concentrations, whereas Kelly Green Seeds KG6902; NC+ Hybrids 7W92; and Fontanelle W‐1000 produced soft kernels with low protein and high starch concentrations (Griess et al, 2010).…”

“…These results indicated that starch granules in the flour from this environment hydrated more slowly (due to the thick protein matrix surrounding the starch granules) and took longer to gelatinize, that the flour slurry was less stable during shear‐force thinning, and that the aligned starch molecules did not reassociate well with each other. Grain produced in this environment would therefore be well suited for food products made by dry milling (Johnson, 2005) and alkaline cooking (Almeida‐Dominguez et al, 1997; Johnson et al, 2010).…”

Relationships Between Simple Grain Quality Parameters for the Estimation of Sorghum and Maize Hardness in Commercial Hybrid Cultivars

“…Quality factors of maize had a narrow range for TW but wider for KS, TKW, TADD, and also for NIT Milling Index (Table IV) (2007) and Johnson et al (2010). TADD hardness was remarkably similar for maize (33.8% ± 6.6%) and sorghum (35.1% ± 7.0%).…”