TY - JOUR
T1 - A comparison of native and oxidized normal and waxy corn starches
T2 - Physicochemical, thermal, morphological and pasting properties
AU - Sandhu, Kawaljit Singh
AU - Kaur, Maninder
AU - Singh, Narpinder
AU - Lim, Seung Taik
PY - 2008/7
Y1 - 2008/7
N2 - The effect of sodium hypochlorite on the physicochemical and functional properties of normal and waxy corn starches was investigated in this study. It was found that both carboxyl and carbonyl contents of oxidized starches from normal corn were higher than those of waxy corn. The introduction of carboxyl and carbonyl groups resulted in lower amylose content and swelling power. Both amylose and amylopectin were oxidized and degraded during oxidation but amylose was more susceptible to oxidation. Studies conducted on paste clarity revealed that the percentage transmittance increased after oxidation. The morphology of the starches was not altered after oxidation. Thermal properties measured by differential scanning calorimeter, showed that oxidation reduced transition temperatures (onset temperature, To; peak temperature, Tp; and conclusion temperature, Tc), gelatinization and retrogradation enthalpies of both normal and waxy corn starches. The retrogradation tendency was reduced after oxidation both in normal and waxy corn starches. Oxidation produced waxy starch with significantly higher peak (PV), trough (TV), breakdown (BV), final (FV), and setback viscosity (SV) as demonstrated by using a rapid visco analyzer. Oxidation reduced the pasting temperature of both normal and waxy corn starches. Also, the principal component analysis (PCA) study was conducted to find the overall variations among the oxidized starches studied. Together, the first two components represent 88.7 g/100 g of the total variability.
AB - The effect of sodium hypochlorite on the physicochemical and functional properties of normal and waxy corn starches was investigated in this study. It was found that both carboxyl and carbonyl contents of oxidized starches from normal corn were higher than those of waxy corn. The introduction of carboxyl and carbonyl groups resulted in lower amylose content and swelling power. Both amylose and amylopectin were oxidized and degraded during oxidation but amylose was more susceptible to oxidation. Studies conducted on paste clarity revealed that the percentage transmittance increased after oxidation. The morphology of the starches was not altered after oxidation. Thermal properties measured by differential scanning calorimeter, showed that oxidation reduced transition temperatures (onset temperature, To; peak temperature, Tp; and conclusion temperature, Tc), gelatinization and retrogradation enthalpies of both normal and waxy corn starches. The retrogradation tendency was reduced after oxidation both in normal and waxy corn starches. Oxidation produced waxy starch with significantly higher peak (PV), trough (TV), breakdown (BV), final (FV), and setback viscosity (SV) as demonstrated by using a rapid visco analyzer. Oxidation reduced the pasting temperature of both normal and waxy corn starches. Also, the principal component analysis (PCA) study was conducted to find the overall variations among the oxidized starches studied. Together, the first two components represent 88.7 g/100 g of the total variability.
KW - Corn starch
KW - Oxidized
KW - Pasting
KW - Physicochemical
KW - Thermal
UR - http://www.scopus.com/inward/record.url?scp=40649110898&partnerID=8YFLogxK
U2 - 10.1016/j.lwt.2007.07.012
DO - 10.1016/j.lwt.2007.07.012
M3 - Article
AN - SCOPUS:40649110898
SN - 0023-6438
VL - 41
SP - 1000
EP - 1010
JO - LWT
JF - LWT
IS - 6
ER -