University of Wisconsin-Madison, Dept. of Food Science, 1605 Linden Drive, Madison, WI 53706, USA.
Food Chem. 2012 Dec 1;135(3):1485-93. doi: 10.1016/j.foodchem.2012.05.102. Epub 2012 Jun 7.
A method to deconvolute overlapping isotope patterns in positive mode matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was developed to determine ratios of A- to B-type interflavan bonds in proanthocyanidins that were isolated from cranberry (Vaccinium macrocarpon, Ait.) press cake (c-PAC). Precision and accuracy was validated for binary mixtures of procyanidins A2 and B2. Deconvolution of c-PAC spectra indicated that oligomers with one or more A-type interflavan bonds occur in a higher proportion than oligomers with all B-type interflavan bonds. c-PAC with at least one A-type bond accounted for more than 91% of the oligomers between trimers and undecamers. The c-PAC isotope patterns are highly repeatable, suggesting that the method can be applied to authentication, standardization and efficacy of cranberry products in relationship to urinary tract health. This is the first time MALDI-TOF MS has been used for estimating ratios of A- to B-type bonds in PAC.
一种用于解析正模式基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）中重叠同位素模式的方法被开发出来，以确定从蔓越莓（Vaccinium macrocarpon，Ait.）压榨饼（c-PAC）中分离出的原花青素中 A 型与 B 型间黄烷键的比例。该方法对原花青素 A2 和 B2 的二元混合物进行了精密度和准确性验证。c-PAC 谱的解析表明，具有一个或多个 A 型间黄烷键的低聚物比具有所有 B 型间黄烷键的低聚物更为常见。至少有一个 A 型键的 c-PAC 低聚物占三聚体和十一聚体之间低聚物的比例超过 91%。c-PAC 的同位素模式高度可重复，表明该方法可应用于蔓越莓产品在泌尿系统健康方面的鉴定、标准化和功效。这是首次使用 MALDI-TOF MS 来估计 PAC 中 A 型与 B 型键的比例。
