氢氧化钙对玉米粉糊化的影响

Effect of lime on gelatinization of heat-treatment corn flour

通过对添加氢氧化钙的玉米粉热处理后其膨胀力、持水性及糊化程度的分析表明,在氢氧化钙浓度范围0%~1%(w/v)内,低浓度的Ca(OH)_2可提高淀粉颗粒的膨胀力和持水性,氢氧化钙浓度大约在0.4%(w/v)时淀粉的膨胀力、持水性和糊化峰值黏度表现为最大,之后随着浓度的增加而减小。通过差示扫描量热仪和高温偏光显微镜显示,玉米粉糊化温度随着Ca(OH)_2浓度的增加先降低后升高。p H较高时能使淀粉羟基电离,并与Ca^(2+)或[CaOH^+]的结合位点结合使Ca(OH)_2与淀粉产生交互作用。

Analysis of swelling power, water retention capacity, and degree of gelatinization of corn flour cooked in water with lime indicated over a concentration rang of 0%~1%（w/v）, that at low concentrations, lime increases swelling and water retention of starch granules. Swelling, water retention, and gelatinization exhibited maxima at or near 0.4%（w/v） lime, and then decreased as lime concentration increased. Differential scanning calorimetry and Hot-stage polarized light revealed first increasing gelatinization temperatures after decreasing with increasing lime concentration. The high p H of the system causes starch hydroxyl groups to ionize, creating binding sites for Ca2＋or [Ca OH＋] and producing Ca-starch crosslinks.