Marta Herlina, Cahyana Yana, Djali Mohamad
Doctoral Program in Agricultural Sciences, Faculty of Agriculture, Universitas Padjadjaran, Bandung, Jawa Barat 46363 Indonesia.
Laboratory of Food Processing Technology, Department of Food Technology, Faculty of Agricultural Industrial Technology, Universitas Padjadjaran, Bandung, Jawa Barat 46363 Indonesia.
J Food Sci Technol. 2021 Jun;58(6):2237-2245. doi: 10.1007/s13197-020-04734-6. Epub 2020 Aug 18.
Factors affecting the extent and rate constant of starch digestion have been determined by applying logarithm of slope (LOS) plot approach to banana starch modified by heat moisture treatment (HMT) at different temperatures (100, 110 and 120 °C) and time (4 and 8 h). LOS plot result showed that native and HMT-starches exhibited two separate digestion rate constants ( in rapid and in slower phase). The digestibility increased with the increase in temperature and time of HMT in which the amount of digestible starch at slower phase ( ) predominantly contributed to the increase in total digestible starch (total ). Small change of the digestible starch in rapid phase ( ) might be attributed to the comparatively intact granule surfaces and the relatively small change in ratio of ordered to disordered α-glucan chains at the granule surface as observed by FTIR-ATR. Meanwhile the increase in might be linked to the decrease in crystallinity as observed by XRD. Compared to the native starch, denser packed-structure characterising an A-type crystalline structure in HMT-starches is a key factor determining the lower in HMT-starches. The densely packed-matrices might slow down the amylase diffusion through the granule to reach digestible α-glucan chains.
通过对在不同温度（100、110和120℃）和时间（4和8小时）下经湿热处理（HMT）的香蕉淀粉应用斜率对数（LOS）图方法，确定了影响淀粉消化程度和速率常数的因素。LOS图结果表明，天然淀粉和HMT淀粉呈现出两个独立的消化速率常数（快速阶段的 和较慢阶段的 ）。消化率随着HMT温度和时间的增加而提高，其中较慢阶段可消化淀粉的量（ ）主要导致总可消化淀粉（总 ）的增加。快速阶段可消化淀粉（ ）的微小变化可能归因于颗粒表面相对完整，以及通过傅里叶变换红外光谱-衰减全反射（FTIR-ATR）观察到的颗粒表面有序与无序α-葡聚糖链比例相对较小的变化。同时，如通过X射线衍射（XRD）观察到的， 的增加可能与结晶度的降低有关。与天然淀粉相比，HMT淀粉中表征A型晶体结构的紧密堆积结构特征是决定HMT淀粉中 较低的关键因素。紧密堆积的基质可能会减缓淀粉酶通过颗粒扩散以到达可消化α-葡聚糖链的速度。
