中把大蕉淀粉的稳定性及酶解动力学

以差示扫描量热法(DSC)和酶水解法研究中把大蕉(Musa × paradisiaca L.)淀粉对热、酸、碱及淀粉酶的稳定性。结果表明：中把大蕉粉主要成分为淀粉，约占干基质量的78% 左右，是一种理想的天然抗性淀粉来源；其糊化起始温度To 为72.10℃、峰值温度Tp 为77.56℃和结束温度Tc 为80.40℃，糊化焓ΔH 为9.698J/g；最大耐酸浓度为0.001mol/L；最大耐碱浓度为0.01mol/L。以中把大蕉淀粉的酶解曲线为基础，采用Wilkinson 统计法求解米氏常数得出：Vm=0.4426mg/(mL·min)，Km=6.566mg/mL，即中把大蕉淀粉的酶解动力学方程为：V=0.4426 ×[S]/(6.566+[S])。

Stability and Enzymatic Kinetics of Plantain Starch

In order to provide theoretical references for the development and application of plantain natural resistant starch, the stability of plantain starch to heat, acid, alkali and amylase was investigated. Results indicated that principal constituent of plantain powder was starch with total amount of 78%. The plantain starch was one of ideal sources of natural resistant starch. Its initial, peak and final gelatinization temperatures were 72.10, 77.56 ℃ and 80.40 ℃, respectively. Its gelatinization enthalpy was 9.698 J/g. The maximum concentrations of plantain starch to resist acid and alkali were 0.001 mol/L and 0.01 mol/L, respectively. Based on the enzymatic hydrolysis curve of plantain starch, an enzymatic kinetic equation, V = 0.4426 × [S]/(6.566 + [S]), was deduced by the Wilkinson method, with Vm and Km of 0.4426 mg/(mL·min) and 6.566 mg/mL, respectively.