TY - JOUR
T1 - Rheological and thermal properties of masa as related to changes in corn protein during nixtamalization
AU - Guzmán, Adriana Quintanar
AU - Jaramillo Flores, María Eugenia
AU - Feria, Javier Solorza
AU - Méndez Montealvo, María Guadalupe
AU - Wang, Ya Jane
PY - 2011/1
Y1 - 2011/1
N2 - Traditional nixtamalization process produces a masa (dough) with appropriate cohesiveness and adhesiveness. Masa is considered as a network of solubilized starch polymers with dispersed, uncooked and swollen starch granules, cell fragments, proteins and lipids. In this work, the influence of proteins on the masa viscoelastic behavior was studied in corn kernels under different nixtamalization conditions. Scanning electron microscopy, SDS-PAGE, differential scanning calorimetry and rheological analysis were used to characterize the corn samples. The micrographs showed that the nixtamalization modified the shape of the starch granules and protein bodies, but no changes in appearance were observed when protein was removed. SDS-PAGE showed that corn proteins polymerized during cooking. Lime promoted both calcium-protein and protein-calcium-protein interactions mainly by calcium bridges, which were difficult to disrupt and increased the protein thermo-resistance. In the absence of lime, corn proteins polymerized mainly by disulfide bond cross-linking. Thermal analysis (DSC) indicated that the gelatinization temperature increased in lime-treated samples compared to control samples. Rheological studies showed that the corn protein exhibited greater influence on gel strength by enhancing the elastic character of the samples (G'). These results suggested that polymerized corn proteins stabilized the gel structure, which in consequence influenced the viscoelastic behavior of masa.
AB - Traditional nixtamalization process produces a masa (dough) with appropriate cohesiveness and adhesiveness. Masa is considered as a network of solubilized starch polymers with dispersed, uncooked and swollen starch granules, cell fragments, proteins and lipids. In this work, the influence of proteins on the masa viscoelastic behavior was studied in corn kernels under different nixtamalization conditions. Scanning electron microscopy, SDS-PAGE, differential scanning calorimetry and rheological analysis were used to characterize the corn samples. The micrographs showed that the nixtamalization modified the shape of the starch granules and protein bodies, but no changes in appearance were observed when protein was removed. SDS-PAGE showed that corn proteins polymerized during cooking. Lime promoted both calcium-protein and protein-calcium-protein interactions mainly by calcium bridges, which were difficult to disrupt and increased the protein thermo-resistance. In the absence of lime, corn proteins polymerized mainly by disulfide bond cross-linking. Thermal analysis (DSC) indicated that the gelatinization temperature increased in lime-treated samples compared to control samples. Rheological studies showed that the corn protein exhibited greater influence on gel strength by enhancing the elastic character of the samples (G'). These results suggested that polymerized corn proteins stabilized the gel structure, which in consequence influenced the viscoelastic behavior of masa.
KW - Nixtamal
KW - Protein cooking
KW - Protein-calcium interactions
KW - Rheology
UR - http://www.scopus.com/inward/record.url?scp=79551630747&partnerID=8YFLogxK
U2 - 10.1016/j.jcs.2010.11.005
DO - 10.1016/j.jcs.2010.11.005
M3 - Artículo
SN - 0733-5210
VL - 53
SP - 139
EP - 147
JO - Journal of Cereal Science
JF - Journal of Cereal Science
IS - 1
ER -