Physicochemical and thermal properties of starches separated from corn produced from crosses of two germ pools

摘要

The changes in physicochemical and thermal properties of starches separated from corn, produced by crossing corn lines of MS and Tux pool, were studied. These heterotic pools were synthesized in a very systematic way by introgressing germplasm on the basis of genetic diversity, pedigree diversity and heterosis. Amylose content, swelling power, solubility and water-binding capacity (WBC) of starches separated from MS x Tux and Tux x MS pool corns were measured. Average amylose content, swelling power, solubility and WBC of MS x Tux pool corn starches were 20.1%, 21.71 g/g, 18.62% and 83.30%, respectively, against 19.6%, 23.23 g/g, 19.27% and 84.13% for those separated from the Tux x MS pool. Thermal properties of starches were measured with differential scanning calorimeter (DSC). Tux x MS pool corn starches showed higher swelling powers, solubilities, onset temperatures of gelatinization (T_0), peak temperature of gelatinization (T_p), conclusion temperature of gelatinization (T_c), enthalpies of gelatinization (ΔH_(gel)), peak height indices (PHI) and synereses than MS x Tux pool corn starches, while the reverse was observed for amylose contents. The relationships between different properties of starches were also determined using Pearson correlation coefficients. Amylose content was negatively correlated with swelling power and WBC (p < 0.05). T_0, T_p, T_c were positively correlated with each other as well as ΔH_(gel) and PHI (p < 0.01). ΔH_(gel) was positively correlated with syneresis (p < 0.01). The crosses, MS x Tux pool, resulted in corn having lower swelling powers, solubilities, transition temperatures but more stable pastes than the corn produced by crossing Tux x MS pool. The effect of selection of parents from the crosses among lines across pools was investigated.