Abstract This study aimed to understand the role of structural disintegration on starch hydrolysis during in vitro digestion. In particular, the impact of in vitro oral processing method (i.e. cutting, cut-and-pestle, blending and grinding) and bread structure (i.e. baked bread, steamed bread and baguette) were investigated. Structural disintegration and starch hydrolysis of bread bolus through oral, gastric and intestinal digestion were characterised. The average starch hydrolysis was 9.5%, 49% and 68% at the end of oral, gastric and intestinal digestion, respectively. The average particle size was decreased from 20 mm2 in the bolus to 109 μm and 73 μm in the chyme and digesta, respectively. Small particle size promoted saliva impregnation and enhanced particle cohesion. Steamed bread was less resistant to structure disintegration, especially during the early stage of gastric digestion. The impact of oral processing was diminished over the digestion process, while the impact of bread type became more predominant. Bread structure played an important role in both gastric and intestinal digestion. The denser bread structure of steamed bread led to a less degree of starch hydrolysis (63%) at a slower rate as compared to the baked bread and baguette (68 and 73%). Results of this study revealed the importance of bread structure and its transformation during in vitro oral processing on the physical and chemical digestion of bread at oral, gastric and intestinal phases.

中文翻译：

---

从食团到食糜：结构分解如何影响面包经口胃肠消化过程中的淀粉水解

摘要 本研究旨在了解结构崩解对体外消化过程中淀粉水解的作用。特别是，研究了体外口腔加工方法（即切割、切杵、混合和研磨）和面包结构（即烤面包、馒头和法式长棍面包）的影响。通过口腔、胃和肠道消化对面包丸的结构分解和淀粉水解进行了表征。口服、胃和肠消化结束时平均淀粉水解率分别为 9.5%、49% 和 68%。平均粒径从大丸剂中的 20 mm2 分别减小到食糜和食糜中的 109 μm 和 73 μm。小粒径促进唾液浸渍并增强颗粒内聚力。馒头对结构分解的抵抗力较差，尤其是在胃消化的早期阶段。口服加工的影响在消化过程中减弱，而面包类型的影响变得更加突出。面包结构在胃和肠消化中都起着重要作用。与烤面包和法式长棍面包（68% 和 73%）相比，馒头的更致密的面包结构导致淀粉水解程度更低（63%）且速度更慢。这项研究的结果揭示了面包结构及其在体外口腔加工过程中的转变对面包在口腔、胃和肠道阶段的物理和化学消化的重要性。面包结构在胃和肠消化中都起着重要作用。与烤面包和法式长棍面包（68% 和 73%）相比，馒头的更致密的面包结构导致淀粉水解程度更低（63%）且速度更慢。这项研究的结果揭示了面包结构及其在体外口腔加工过程中的转变对面包在口腔、胃和肠道阶段的物理和化学消化的重要性。面包结构在胃和肠消化中都起着重要作用。与烤面包和法式长棍面包（68% 和 73%）相比，馒头的更致密的面包结构导致淀粉水解程度更低（63%）且速度更慢。这项研究的结果揭示了面包结构及其在体外口腔加工过程中的转变对面包在口腔、胃和肠道阶段的物理和化学消化的重要性。