Quebracho (QUE) and chestnut (CHE) are natural sources of tannins, but there are no connection between QUE, CHE and human health. The study investigated the antioxidant response and metabolization of tannin extracts trough in vitro digestion-fermentation. The FRAP assay pointed a higher reducing capacity of CHE than QUE (6.90 vs. 5.07 mmol Trolox/g), in contrast to a stronger scavenging activity of QUE (8.16 mmol Trolox/g vs 6.70 mmol Trolox/g). The results obtained showed a decrease of the antioxidant capacity of tannins after microbial fermentation, but a high prebiotic activity through release of short-chain fatty acids of both CHE (11.14 mmol/g) and QUE (4.79 mmol/g) was observed. The UPLC-MS investigations on digested and fermented tannins gave an identification and semi-quantification of 18 compounds, including hydrolysable and condensed tannins and their metabolites. The results represent a valid basis for further studies on the potential use of these wood extracts in human diet.

Quebracho（QUE）和栗子（CHE）是单宁的天然来源，但QUE，CHE和人体健康之间没有联系。该研究调查了单宁提取物在体外的抗氧化反应和代谢消化发酵。FRAP分析表明CHE的还原能力高于QUE（6.90对5.07 mmol Trolox / g），而QUE的清除能力更高（8.16 mmol Trolox / g对6.70 mmol Trolox / g）。所获得的结果表明，微生物发酵后单宁的抗氧化能力降低，但是通过释放CHE（11.14 mmol / g）和QUE（4.79 mmol / g）的短链脂肪酸而观察到了很高的益生元活性。通过UPLC-MS对消化和发酵的单宁进行的研究鉴定和半定量了18种化合物，包括可水解和浓缩的单宁及其代谢产物。该结果为进一步研究这些木材提取物在人类饮食中的潜在用途提供了有效的基础。