Department of Animal Sciences, University of Wisconsin-Madison, Reed Research Group, 1675 Observatory Drive, Madison, WI 53706, USA.
Complete Phytochemical Solutions, LLC, 275 Rodney Road, Cambridge, WI 53523, USA.
J AOAC Int. 2021 Mar 5;104(1):223-231. doi: 10.1093/jaoacint/qsaa106.
Cranberry proanthocyanidins (c-PAC) are oligomeric structures of flavan-3-ol units, which possess A-type interflavan bonds. c-PAC differs from other botanical sources because other PAC mostly have B-type interflavan bonds. Cranberry products used to alleviate and prevent urinary tract infections may suffer from adulteration, where c-PAC are replaced with less expensive botanical sources of PAC that contain B-type interflavan bonds.
Identifying the presence of A-type interflavan bonds in cranberry fruit and dietary supplements.
Thirty-five samples reported to contain A-type PAC (cranberry fruit and cranberry products) and 36 samples reported to contain B-type PAC (other botanical sources) were identified and differentiated using MALDI-TOF MS, deconvolution of overlapping isotope patterns, and principal component analysis (PCA).
Our results show that both MALDI-TOF MS and deconvolution of overlapping isotope patterns were able to identify the presence of A-type interflavan bonds with a probability greater than 90% and a confidence of 95%. Deconvolution of MALDI-TOF MS spectra also determined the ratio of A-type to B-type interflavan bonds at each degree of polymerization in cranberry fruit and cranberry products, which is a distinguishing feature of c-PAC in comparison to other botanical sources of PAC. PCA shows clear differences based on the nature of the interflavan bonds.
MALDI-TOF MS, deconvolution of overlapping isotope patterns of MALDI-TOF MS spectra, and PCA allow the identification, estimation, and differentiation of A-type interflavan bonds in cranberry-based foods and dietary supplements among other botanical sources containing mostly B-type interflavan bonds.
蔓越莓原花青素（c-PAC）是黄烷-3-醇单元的寡聚结构，具有 A 型间黄烷键。c-PAC 与其他植物来源不同，因为其他 PAC 大多具有 B 型间黄烷键。用于缓解和预防尿路感染的蔓越莓产品可能会受到掺假，其中 c-PAC 被更便宜的具有 B 型间黄烷键的植物来源 PAC 所取代。
鉴定蔓越莓果实和膳食补充剂中 A 型间黄烷键的存在。
鉴定并区分了 35 种报告含有 A 型 PAC（蔓越莓果实和蔓越莓产品）的样品和 36 种报告含有 B 型 PAC（其他植物来源）的样品，使用 MALDI-TOF MS、重叠同位素模式的解卷积和主成分分析（PCA）。
我们的结果表明，MALDI-TOF MS 和重叠同位素模式的解卷积都能够以大于 90%的概率和 95%的置信度识别 A 型间黄烷键的存在。MALDI-TOF MS 光谱的解卷积还确定了每个聚合度下蔓越莓果实和蔓越莓产品中 A 型与 B 型间黄烷键的比例，这是 c-PAC 与其他 PAC 植物来源的区别特征。PCA 基于间黄烷键的性质显示出明显的差异。
MALDI-TOF MS、MALDI-TOF MS 光谱重叠同位素模式的解卷积以及 PCA 允许鉴定、估计和区分基于蔓越莓的食品和膳食补充剂中的 A 型间黄烷键，以及其他主要含有 B 型间黄烷键的植物来源。
