酸解对不同链/支比含量玉米淀粉特性的影响

以4种不同链/支比含量的玉米淀粉为原料,酸解处理不同时间,以酸解玉米淀粉的形貌特性、冻融稳定性、膨胀度、溶解度、晶体性质为指标衡量不同酸解时间对玉米淀粉结构性质的影响。结果表明:4种玉米淀粉酸水解程度的顺序为:蜡质玉米普通玉米淀粉G50G80。酸解后,同品种的4种玉米淀粉的析水率随着酸解天数的增加而增加;溶解度增加,膨胀度降低。酸解并未改变淀粉的晶型,随着酸解时间的延长,蜡质玉米淀粉和普通玉米的相对结晶度先增大后保持不变,G50和G80的相对结晶度随着酸解时间的增加而增大。表明酸解对低直链淀粉(蜡质玉米淀粉和普通玉米淀粉)的结构、性能影响最大。

Effect of Acid Hydrolysis on the Characteristics of Corn Starch with different Amylose content

Technological functional properties of native and acid-thinned corn starch with different amylose content were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed and evaluated before and after the hydrolysis reaction in terms of morphologies, freeze-thaw stability, swelling power, solubility and X-ray crystallinity of the acid-thinned. The results show that the hydrolysis degree order was waxy corn starch > normal corn starch > G50 >G80. Acid thinning decreased the freeze-thaw stability and the swelling power but increased the solubility. X-ray diffraction results revealed that acid thinning did not change the starch crystal pattern. Gradual increase in crystallinity occurred during the first six days, followed by remain the same in the waxy and normal corn starch. However, the relative crystallinity of G50 and G80 increaed with the increasing hydrolyse time. High amylopectin starch (waxy and normal corn starch) was more susceptible to degradation during hydrolysis process than high amylose corn starch (G50 and G80) as revealed by the morphologies, pasting properties and crystallinity values.