Center for the Valorization of Amazonian Bioactive Compounds (CVACBA), Federal University of Pará (UFPA), Belém 66075-750, PA, Brazil.
Institute of Coastal Studies, Federal University of Pará (UFPA), Bragança 68600-000, PA, Brazil.
Molecules. 2022 Dec 21;28(1):66. doi: 10.3390/molecules28010066.
The chemical mechanism of the acid cleavage of proanthocyanidins (PAs) has been known for decades but has yet to be optimized. Therefore, we optimized this process in Byrsonima crassifolia, Euterpe oleracea and Inga edulis extracts using the response surface methodology and assessed the effect of hydrochloric acid concentration (0.3−3.7 N), time (39−291 min), and temperature (56−98 °C) on the following response variables: PAs reduction, astringency reduction, antioxidant capacity/total polyphenols (TEAC/TP) ratio, and cyanidin content. The response variables were maximized when cleavage was performed with 3 N HCl at 88 °C for 165 min. Under these conditions, the mean PAs value and astringency in the three extracts decreased by 91% and 75%, respectively, the TEAC/TP ratio remained unchanged after treatment (p > 0.05), and the increase in cyanidin confirmed the occurrence of cleavage. Thus, the results suggest that acid cleavage efficiently minimizes undesirable technological PAs characteristics, expanding the industrial applications.
原花青素（PAs）的酸裂解的化学机制已经为人所知数十年，但尚未得到优化。因此，我们使用响应面法优化了 Byrsonima crassifolia、Euterpe oleracea 和 Inga edulis 提取物中的这一过程，并评估了盐酸浓度（0.3-3.7 N）、时间（39-291 分钟）和温度（56-98°C）对以下反应变量的影响：PAs 减少、涩味减少、抗氧化能力/总多酚（TEAC/TP）比和矢车菊素含量。当在 88°C 下用 3 N HCl 处理 165 分钟时，反应变量达到最大值。在此条件下，三种提取物中的平均 PAs 值和涩味分别降低了 91%和 75%，处理后 TEAC/TP 比保持不变（p>0.05），矢车菊素的增加证实了裂解的发生。因此，结果表明酸裂解能有效地最小化不良的技术 PAs 特性，扩大工业应用。
