Department of Carbohydrate Analyses, Eurofins Food Netherlands, Leeuwarderstraatweg 129, 8441 PK Heerenveen, The Netherlands.
Food Chem. 2013 Oct 1;140(3):574-80. doi: 10.1016/j.foodchem.2012.10.109. Epub 2012 Nov 24.
The dietary fibre (DF) content in wheat grain based food products have been established with both the classical AOAC 985.29 dietary fibre and the new AOAC 2009.01 total dietary fibre protocol. There is a good agreement between the high molecular weight dietary fibre (HMWDF) contents measured with the AOAC 2009.01 method and (DF) content measured with the classical AOAC 985.29 method in wheat grain based food products. With the AOAC 2009.01 method also a significant amount of low molar weight dietary fibre (LMWDF), ranging from 1% to 3% w/w, was measured which is not quantified with the AOAC 985.29 method. With semi-preparative GPC the LMWDF (DP⩾3) fractions in the wheat grain based food products were isolated. The monosaccharide composition of the dissolved LMWDF constituents was determined. Glucose was by far the most abundant monosaccharide present with arabinose, galactose, xylose and mannose as minor constituents. It appeared that the LMWDF contains still not fully converted digestible starch/malto-oligosaccharide fragments with DP⩾3, which are erroneously quantified as LMWDF. By introducing an extra AMG hydrolysis step in the AOAC 2009.01 protocol after evaporation of the ethanol and dissolving the residue in deionised water, these malto-oligosaccharides are fully hydrolysed resulting in that way in a correct and lower LMWDF content.
以小麦谷物为基础的食品中的膳食纤维（DF）含量已通过经典的 AOAC 985.29 膳食纤维和新的 AOAC 2009.01 总膳食纤维方案进行了确定。在以 AOAC 2009.01 方法测量的高分子量膳食纤维（HMWDF）含量与以经典 AOAC 985.29 方法测量的（DF）含量之间存在良好的一致性。使用 AOAC 2009.01 方法，还测量到相当数量的低摩尔质量膳食纤维（LMWDF），其范围为 1%至 3%w/w，这是 AOAC 985.29 方法无法量化的。通过半制备 GPC 分离了小麦谷物为基础的食品中的 LMWDF（DP⩾3）级分。测定了溶解的 LMWDF 成分的单糖组成。葡萄糖是最丰富的单糖，阿拉伯糖、半乳糖、木糖和甘露糖是次要成分。似乎 LMWDF 含有尚未完全转化的可消化淀粉/麦芽糖低聚糖片段，其 DP ⩾3，这些片段被错误地定量为 LMWDF。通过在 AOAC 2009.01 方案中在蒸发乙醇和将残渣溶解在去离子水中后引入额外的 AMG 水解步骤，这些麦芽糖完全水解，从而以正确且较低的 LMWDF 含量获得结果。
