Long- and short-range structural changes of recrystallised cassava starch subjected to in vitro digestion
Long- and short-range structural changes of recrystallised cassava starch subjected to in vitro digestion
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DOI：
10.1016/j.foodhyd.2010.07.023
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发表时间：
2011-05-01
影响因子：
10.7
通讯作者：
Rohm, H.
中科院分区：
文献类型：
--
作者：
Mutungi, C.;Onyango, C.;Rohm, H.
研究了由木薯淀粉制备的III型抗性淀粉的构象和结构顺序。糊化淀粉用普鲁兰酶脱支，然后通过退火、温度循环或热湿处理进行重结晶。随后，使用猪胰α-淀粉酶和淀粉葡糖苷酶对重结晶产物进行体外消化。采用高效阴离子交换色谱、广角X射线衍射、傅里叶变换红外光谱、（13）C CP/MAS核磁共振和差示扫描量热法分别对未消化和消化产物的聚合物链分布、结晶度、分子有序性、结构构象和热稳定性进行了分析。消化后平均聚合度从20增加到22葡萄糖单位。未消化的和消化的淀粉都包含A、B和V结晶类型的混合物。X-射线衍射分析表明，退火、温度循环和湿热处理后淀粉的堆积率分别为40.9%、50.7%和56.2%。在消化产物中，这些值分别增加到47.9%、54.4%和58.2%。用（13）C CP/MAS核磁共振测定了未消化退火、温度循环和湿热处理淀粉中的有序组分分别为69.3%、71.4%和79.2%。而在酶解产物中，尽管非结晶构象的含量显著（p < 0.01）较高，但无序相不明显。的消化残留物的熔融的淀粉含量增加了2.50的退火，2.53的温度循环和2.06的热湿处理的淀粉的因素，这表明分子重排的方式与酶的敏感性的初始材料。(C)2010爱思唯尔有限公司版权所有。
The conformational and structural order of resistant starch type III made from cassava starch was studied. The gelatinized starch was debranched using pullulanase and then recrystallised by annealing, temperature-cycling or heat-moisture treatment. Subsequently, the recrystallised products were subjected to in vitro digestion using porcine pancreatic alpha-amylase and amyloglucosidase. The undigested and digested products were analyzed for polymer chain distribution, crystallinity, molecular order, structural conformations and thermal stability using high performance anion exchange chromatography, wide angle X-ray diffraction, Fourier transform infrared spectroscopy, (13)C CP/MAS nuclear magnetic resonance and differential scanning calorimetry, respectively. Average degree of polymerisation increased from 20 to 22 glucose units upon digestion. Both the undigested and digested starches comprised mixtures of A, B and V crystalline types. Percentage of crystallinities by X-ray diffraction were 40.9%, 50.7% and 56.2% in annealed, temperature-cycled and heat-moisture treated starches, respectively. These values increased to 47.9%, 54.4% and 58.2%, respectively, in the digested products. The ordered fractions in the undigested annealed, temperature-cycled and heat-moisture treated starches were 69.3%, 71.4% and 79.2%, respectively, as determined by (13)C CP/MAS nuclear magnetic resonance. However, the disordered phase was indistinct in the digested products although the contents of non-crystalline conformations were significantly (p < 0.01) higher. The melting enthalpies of the digested residues increased by factors of 2.50 in annealed, 2.53 in temperature-cycled and 2.06 in heat-moisture treated starches, suggesting molecular rearrangement in a manner related to the enzyme susceptibility of the initial materials. (C) 2010 Elsevier Ltd. All rights reserved.