International Chemistry Testing, Milford, MA, USA.
Methods and Application of Food Composition Laboratory, USDA, ARS, Beltsville Human Nutrition Research Center, Beltsville, MD, USA.
Phytochem Anal. 2020 Nov;31(6):874-883. doi: 10.1002/pca.2952. Epub 2020 May 29.
American cranberries (Vaccinium macrocarpon) contain primarily A-type proanthocyanidins (PACs), which have been shown to prevent urinary tract infection. Currently, the accurate quantification of cranberry PACs is still lacking.
A normal-phase high-performance liquid chromatography (NP-HPLC) method using relative response factors was developed and validated to quantify cranberry PAC oligomers and polymers.
PAC oligomers with degree of polymerisation (DP) 3-9 and total polymers were isolated from the cranberry juice concentrate. Characterisation of the isolated PAC oligomers was performed by ultra-performance liquid chromatography-high resolution mass spectrometry. The relative response factors of oligomers from DP 2-9 and total polymers were determined against procyanidin A2. Method validation was conducted to assess limit of detection, limit of quantification, the linearity and working range, precision and accuracy. In addition, quantifications of PACs by NP-HPLC using relative response factors and two other commonly used methods were conducted in three cranberry food products.
Cranberries PACs oligomers contained both A-type and B-type linkage, with epicatechin and epigallocatechin as basic units. Method validation results suggested this method is reliable and reproducible. Quantifications of PACs by NP-HPLC using relative response factors yielded higher values than that by the other two methods.
A NP-HPLC method using the relative response factors was developed and validated. This method provides a more accurate approach in determining cranberry PACs. It can be used to quantify individual oligomers from DP 2-9, total polymers and total PACs in cranberries and cranberry products.
美洲蔓越莓（Vaccinium macrocarpon）主要含有 A 型原花青素（PACs），已被证实可预防尿路感染。目前，对蔓越莓 PAC 的准确定量仍存在不足。
建立并验证一种正相高效液相色谱（NP-HPLC）法，采用相对响应因子定量测定蔓越莓 PAC 低聚体和聚合物。
从蔓越莓浓缩汁中分离出聚合度（DP）为 3-9 的 PAC 低聚体和总聚合物。采用超高效液相色谱-高分辨质谱法对分离得到的 PAC 低聚体进行表征。采用相对响应因子测定 DP 为 2-9 的低聚体和总聚合物的相对响应因子。通过检测检测限、定量限、线性和工作范围、精密度和准确度对方法进行验证。此外，采用 NP-HPLC 法测定三种蔓越莓食品中的 PACs，同时使用相对响应因子和另外两种常用方法进行定量分析。
蔓越莓 PACs 低聚体含有 A 型和 B 型连接，以表儿茶素和表没食子儿茶素没食子酸酯为基本单元。方法验证结果表明该方法可靠且重现性好。采用相对响应因子的 NP-HPLC 法测定的 PACs 含量高于另外两种方法。
建立并验证了一种采用相对响应因子的 NP-HPLC 法。该方法为测定蔓越莓 PACs 提供了更准确的方法。可用于定量分析蔓越莓及其制品中的 DP 为 2-9 的低聚体、总聚合物和总 PACs。
