Rearranged supramolecular structure of resistant starch with polymorphic microcrystals prepared in high-solid enzymatic system
Rearranged supramolecular structure of resistant starch with polymorphic microcrystals prepared in high-solid enzymatic system
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DOI：
10.1016/j.foodhyd.2021.107215
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发表时间：
2022
影响因子：
10.7
通讯作者：
Junyu Tang;Jianwei Zhou;Xinyue Zhou;Dandan Li;Zhengzong Wu;Jinhu Tian;Enbo Xu;Donghong Liu
中科院分区：
文献类型：
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作者：
Junyu Tang;Jianwei Zhou;Xinyue Zhou;Dandan Li;Zhengzong Wu;Jinhu Tian;Enbo Xu;Donghong Liu
抗性淀粉（RS）作为一种新型膳食纤维得到了广泛的应用，但在制备单组分纯相抗性淀粉时，其微观结构和聚合物结构的可控形成仍是一个局限。本研究以直链淀粉与支链淀粉的两种比例（raa1:1和RAA1:2）和4种普鲁兰酶浓度（5、15、25、35 U/g）的玉米淀粉为原料，在高固相动态生物挤出环境下制备RS。基于糖苷键（13C NMR）、链长分布（SEC/FACE）、单螺旋/双螺旋（FTIR）、片层（SAXS）和晶型（XRD）所反映的长、短程序列，阐明了淀粉的重排超分子结构及其与理化性质（DSC和RVA）的关系。形成两种RS形态：1)RAA1:1-P15和RAA1:2-P35具有高RS含量（54.95和54.19%）和短支链淀粉（DP≤24）（70.52%和60.20%）的无序融合样结构。较短（A链）和极短（DP < 6）的支链淀粉有助于在低水分条件下挤压基质中形成具有B1链的亚微晶；2) RAA1:2-P15显示出更薄、更鳞状和层状结构，这是大颗粒的厚层状条带的过渡状态。SDS含量高（33.61%），具有较大的重排洛伦兹（16.97 nm）。综上所述，本研究中直链淀粉和支链淀粉在不同结构单元或微结构域淀粉改性中的纠缠状态将为探索新型RS的制备提供新的思路和参考。
Resistant starch (RS) is widely used as a new type of dietary fiber, but it is still a limitation of controllable formation of microstructure and polymeric architecture for preparing single-component RS (pure-phase). In this study, RS was prepared using maize starch with two ratios of amylose to amylopectin (RAA1:1and RAA1:2) and four pullulanase concentrations (5, 15, 25, 35 U/g) in a high-solid dynamic reaction environment of bio-extrusion. Based on the long- and short-range orders reflected by the glycosidic bonds (13C NMR), chain-length distributions (SEC/FACE), single-/double-helices (FTIR), lamellas (SAXS) and crystalline pattern (XRD), the rearranged supramolecular structure of starch and their relationships with physicochemical properties (DSC and RVA) was illuminated. There were two morphologies of RS were created: 1) disordered fusion-like structure displayed by RAA1:1-P15 and RAA1:2-P35, which had the high contents of RS (54.95 and 54.19%) and short amylopectin (DP ≤ 24) (70.52% and 60.20%). The short (A chains) and extremely short (DP < 6) amylopectin could contribute to form submicro-crystallite with B1 chains in the extruded matrix at a low moisture level; 2) thinner, scalier and layered-like structure displayed by RAA1:2-P15 that was the transition state from thick layered strips of large granules. Its SDS content was high (33.61%) and owned the larger rearrangeddLorentz(16.97 nm). Overall, the entangled regime of amylose and amylopectin in the modifications of starch with different structural units or micro-domains in this study will provide a new idea and reference to explore the preparation of novel RS.