About 85% of proanthocyanidins in the American cranberries are polymers with degree of polymerization above 4. These polymers have lower absorption rates and bioactivities than oligomers of smaller sizes. In the present study, proanthocyanidin polymers were separated from cranberries using a two‐step chromatographic method and depolymerized into a mixture of monomers, dimers, trimers, and tetramers. Adding epicatechin as a chain breaker yielded 1659 mg oligomers per gram of polymers compared to a yield of 221 mg oligomers in the absence of epicatechin under predicted optimal conditions. Predictive modeling using response surface methodology showed that higher yields of oligomers were achieved at higher temperature and moderate acid concentration in the presence of epicatechin. Shorter reaction time and high acid concentration were favored in the absence of epicatechin. This research provided a practical approach to depolymerize proanthocyanidin polymers and had the potential to increase bioavailability and bioactivity of proanthocyanidins in cranberry extracts.

中文翻译：

---

从美国蔓越莓中分离原花色素聚合物，并使用响应面方法对解聚进行预测建模

在美洲蔓越莓中，约85％的原花色素是聚合度高于4的聚合物。这些聚合物的吸收率和生物活性均低于较小尺寸的低聚物。在本研究中，原花青素聚合物使用两步色谱法从小红莓中分离出来，并解聚为单体，二聚体，三聚体和四聚体的混合物。加入表儿茶素作为链断裂剂，每克聚合物可产生1659 mg的低聚物，而在预测的最佳条件下不存在表儿茶素的情况下可产生221 mg的低聚物。使用响应表面方法进行的预测建模表明，在存在表儿茶素的情况下，在较高的温度和中等的酸浓度下，可以获得较高的低聚物收率。在没有表儿茶素的情况下，较短的反应时间和较高的酸浓度是有利的。这项研究提供了一种解原花青素聚合物解聚的实用方法，并有可能提高酸果蔓提取物中原花青素的生物利用度和生物活性。