TY - JOUR
T1 - Calcium content and speciation in alkaline-cooked corn studied bysynchrotron Ca K-edge X-ray absorption spectroscopy
AU - Caballero-Briones, F.
AU - Espinosa-Faller, F. J.
AU - Rejón, V.
AU - Chalé, F.
AU - Hernández-Rodríguez, E.
AU - Zapata-Navarro, A.
AU - Peña, J. L.
N1 - Funding Information:
During the writing of this manuscript Dr. A. Zapata-Navarro passed away: authors would like to dedicate this work to his memory. FCB and JLP acknowledge Dr. E. Yu, Dr. I. Pickering and Dr. G. Greene at SSRL for the scientific support. W. Cauich is acknowledged for SEM measurements. This work was financed by projects CONACYT 151679 and 169108 .
PY - 2014/7
Y1 - 2014/7
N2 - Using Ca K-edge X-ray absorption spectroscopy the calcium uptake and species in alkaline corn have been studied and compared with corn starch and crystalline cellulose as main compounds in corn endosperm and pericarp. XANES data showed that calcium binds preferably to hemicelluloses in the pericarp. The main calcium species found by EXAFS in cellulose and starch is calcium carbonate although some protein-calcium species could be formed within the starch granules. From X-ray diffraction and microscopy techniques, pericarp dissolution, mainly at the amorphous hemicellulose fraction was inferred. The hemicellulose dissolution during steeping increases the apparent pericarp crystallinity, while the relative calcium content determined by XANES absorption edges reduces. XANES and EXAFS spectroscopies showed to be a valuable tool in order to determine the calcium species and to make a semiquantitative determination of calcium in the different nixtamalized corn fractions.
AB - Using Ca K-edge X-ray absorption spectroscopy the calcium uptake and species in alkaline corn have been studied and compared with corn starch and crystalline cellulose as main compounds in corn endosperm and pericarp. XANES data showed that calcium binds preferably to hemicelluloses in the pericarp. The main calcium species found by EXAFS in cellulose and starch is calcium carbonate although some protein-calcium species could be formed within the starch granules. From X-ray diffraction and microscopy techniques, pericarp dissolution, mainly at the amorphous hemicellulose fraction was inferred. The hemicellulose dissolution during steeping increases the apparent pericarp crystallinity, while the relative calcium content determined by XANES absorption edges reduces. XANES and EXAFS spectroscopies showed to be a valuable tool in order to determine the calcium species and to make a semiquantitative determination of calcium in the different nixtamalized corn fractions.
KW - Alkaline cooked corn
KW - Calcium speciation
KW - Calcium uptake
KW - XAS
UR - http://www.scopus.com/inward/record.url?scp=84901942448&partnerID=8YFLogxK
U2 - 10.1016/j.jcs.2014.02.005
DO - 10.1016/j.jcs.2014.02.005
M3 - Artículo
SN - 0733-5210
VL - 60
SP - 7
EP - 10
JO - Journal of Cereal Science
JF - Journal of Cereal Science
IS - 1
ER -