Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
Institute of Agrophysics Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland.
Food Chem. 2018 Jun 30;252:198-206. doi: 10.1016/j.foodchem.2018.01.110. Epub 2018 Jan 20.
FTIR spectroscopy was used to determine changes in secondary structure, as well as water state, in gluten and model doughs supplemented by four fibre polysaccharides (microcrystalline cellulose, inulin, apple pectin and citrus pectin). The gluten and model doughs were obtained from commercially available wheat gluten and model flour, respectively. The polysaccharides were used in five concentrations: 3%, 6%, 9%, 12% and 18%. Analysis of the FTIR spectra indicated that polysaccharides could be divided into two groups: first - microcrystalline cellulose and inulin, second - apple and citrus pectins that induced opposite structural changes. Changes in secondary structure concern mainly β-sheets and β-turns that form aggregated β-structures, suggesting dehydration of the gluten matrix as a result of competition for water between gluten proteins and polysaccharides. Moreover, the positive band at ca. 1226 cm in the spectra of pectin-modified samples indicates formation of 'ether' type hydrogen bonds between gluten proteins and pectins.
傅里叶变换红外光谱（FTIR）被用于测定经四种纤维多糖（微晶纤维素、菊粉、苹果果胶和柑橘果胶）添加后，面筋和模型面团的二级结构和水分状态的变化。面筋和模型面团分别由市售小麦面筋和模型面粉制成。多糖的使用浓度为 3%、6%、9%、12%和 18%。FTIR 光谱分析表明，多糖可以分为两组：第一组为微晶纤维素和菊粉，第二组为苹果果胶和柑橘果胶，它们引起了相反的结构变化。二级结构的变化主要涉及形成聚集态β结构的β-折叠和β-转角，表明由于面筋蛋白和多糖之间对水的竞争，导致面筋基质脱水。此外，果胶改性样品光谱中约 1226 cm 的正带表明，在面筋蛋白和果胶之间形成了“醚”型氢键。
