Patel Hamung, Day Richard, Butterworth Peter J, Ellis Peter R
King's College London, School of Medicine, Diabetes and Nutritional Sciences Division, Biopolymers Group, Franklin-Wilkins Building, 150, Stamford Street, London SE1 9NH, UK.
King's College London, School of Medicine, Diabetes and Nutritional Sciences Division, Biopolymers Group, Franklin-Wilkins Building, 150, Stamford Street, London SE1 9NH, UK.
Carbohydr Polym. 2014 Nov 26;113:182-8. doi: 10.1016/j.carbpol.2014.06.089. Epub 2014 Jul 10.
The rate and extent of digestibility of starch were analysed using the logarithm of the slope (LOS) method. Digestibility curves with α-amylase were obtained for starches in their native, gelatinised and 24h retrograded form. A LOS plot of the digestibility curves was then constructed, which allowed the rate constant (k) and the concentration of the product at the end of the reaction (C∞) to be calculated. It also allowed the identification of rapid and slow phases in starch digestion. Upon gelatinisation, both k and C∞ increased with dramatic changes notably in C∞; however after starch samples had been stored for 24h at room temperature, k was not affected but C∞ decreased. This suggests that retrograded starch is virtually inert to amylase action. Both k and C∞ were strongly related to the increase in degree of order of the α-glucan chains, monitored by FTIR-ATR spectroscopy, in retrograded starch.
采用斜率对数（LOS）法分析淀粉的消化率和消化程度。获得了天然、糊化和24小时回生形式淀粉与α-淀粉酶的消化曲线。然后构建了消化曲线的LOS图，据此可以计算反应速率常数（k）和反应结束时产物的浓度（C∞）。它还可以识别淀粉消化中的快速和慢速阶段。糊化后，k和C∞均增加，C∞变化显著；然而，淀粉样品在室温下储存24小时后，k不受影响，但C∞降低。这表明回生淀粉实际上对淀粉酶作用呈惰性。通过傅里叶变换红外衰减全反射光谱（FTIR-ATR）监测，k和C∞均与回生淀粉中α-葡聚糖链有序度的增加密切相关。
