School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand; The New Zealand Institute for Plant & Food Research Limited, Private Bag 4704, Christchurch Mail Centre, Christchurch 8140, New Zealand.
Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand; The New Zealand Institute for Plant & Food Research Limited, Private Bag 4704, Christchurch Mail Centre, Christchurch 8140, New Zealand.
Food Res Int. 2021 Feb;140:109988. doi: 10.1016/j.foodres.2020.109988. Epub 2020 Dec 24.
Previous work has shown that baking induces structural changes within the gluten macropolymer (GMP) that reduce gluten protein digestibility. The precise nature of these structural changes within dough/bread, and how they alter the in vitro release profile of immunogenic gluten peptides that activate celiac disease is unknown. This work examined the effect of dough baking temperature and duration on the GMP's structure and the release profile of immunogenic gluten peptides. Dough was baked at either 150 °C or 230 °C for 25, 35 or 45 min. The structure of the GMP within the resulting loaves was defined and compared using confocal microscopy, quantitative protein network analysis, gliadin protein extractability (HPLC) and determination of the free thiol content. Both bread and dough were digested in vitro (INFOGEST) and the release profile of six immunogenic gluten peptides (including the immunodominant 33mer) defined using quantitative mass spectrometry. Higher baking temperatures and longer durations increased the degree of intermolecular disulfide bonds between the sulfur-rich gliadins and GMP backbone. The thermal load did not alter the GMP macrostructure, but significant differences between bread and dough were observed. Baking altered the concentration and release profile of the immunogenic gluten peptides throughout in vitro digestion causing the digestion of immunogenic gluten peptides differed between raw and heat-treated bread.
先前的研究表明，烘焙会导致面筋高分子聚合物（GMP）的结构发生变化，从而降低面筋蛋白的消化率。然而，我们对于面团/面包内部这些结构变化的具体性质以及它们如何改变免疫原性谷朊肽在体外的释放模式，从而引发乳糜泻，还知之甚少。本研究旨在探讨面团烘焙温度和时间对 GMP 结构以及免疫原性谷朊肽释放模式的影响。面团分别在 150°C 或 230°C 下烘焙 25、35 或 45 分钟。利用共聚焦显微镜、定量蛋白质网络分析、醇溶谷蛋白提取率（HPLC）和游离巯基含量来定义和比较所得面包内部 GMP 的结构。采用 INFOGEST 体外消化法对面包和面团进行消化，并利用定量质谱法来确定六种免疫原性谷朊肽（包括免疫优势 33mer）的释放模式。较高的烘焙温度和较长的烘焙时间会增加富含硫的醇溶谷蛋白与 GMP 主链之间的分子间二硫键程度。热负荷并未改变 GMP 的宏观结构，但在面包和面团之间观察到了显著差异。烘焙会改变免疫原性谷朊肽在整个体外消化过程中的浓度和释放模式，导致生面包和热处理面包的免疫原性谷朊肽消化方式不同。
