软木树皮是林业产业的重要副产品。目前,树皮未得到充分利用，主要用于能源生产，尽管它可以用热水提取以获得用于增值用途的化合物。在挪威云杉（云杉[L.]喀斯特。)树皮，缩合单宁和二苯乙烯苷是构成大部分抗氧化提取物的化合物。为了开发可行的软木树皮提取物生产链，了解原材料质量至关重要。这项研究通过两个季节性重复研究了云杉树皮单宁和二苯乙烯在储存过程中的命运（即，在冬季和夏季)。在实验中,收获成熟的原木并在外面储存。在六个月的储存期间，定期从内部和外部树皮层收集样品进行化学分析。此外,通过FRAP分析树皮提取物的抗氧化活性，ORAC,和H2O2清除试验。根据结果,二苯乙烯在储存过程中迅速降解，而单宁更稳定：仅占原始二苯乙烯量的5-7％，约。在24周储存后发现了原始量的30-50％的缩合单宁。夏季条件导致树皮化学比冬季条件更快地改变。抗氧化活性的变化不如分析的化合物明显，这表明该化合物的衍生物有助于抗氧化活性。检测结果表明,平均而言,CA.27％的原始抗氧化能力在开始储存处理后24周保持，虽然在测定之间发现了很大的差异（剩余的原始容量的2-95％），季节,和树皮层。内树皮比外树皮保留其活动时间更长，附着在木材上的完整树皮预计将比被剥皮的树皮维持更长时间。因此，为了确保长期质量，建议不要在储存前剥皮:外层树皮保护内层树皮，剥皮会加剧退化。
Softwood bark is an important by-product of forest industry. Currently, bark is under-utilized and mainly directed for energy production, although it can be extracted with hot water to obtain compounds for value-added use. In Norway spruce (Picea abies [L.] Karst.) bark, condensed tannins and
stilbene glycosides are among the compounds that comprise majority of the antioxidative extractives. For developing feasible production chain for softwood bark extractives, knowledge on raw material quality is critical. This study examined the fate of spruce bark tannins and stilbenes during storage treatment with two seasonal replications (i.e., during winter and summer). In the experiment, mature logs were harvested and stored outside. During six-month-storage periods, samples were periodically collected for chemical analysis from both inner and outer bark layers. Additionally, bark extractives were analyzed for antioxidative activities by FRAP, ORAC, and H2O2 scavenging assays. According to the results, stilbenes rapidly degraded during storage, whereas tannins were more stable: only 5-7% of the original
stilbene amount and ca. 30-50% of the original amount of condensed tannins were found after 24-week-storage. Summer conditions led to the faster modification of bark chemistry than winter conditions. Changes in antioxidative activity were less pronounced than those of analyzed chemical compounds, indicating that the derivatives of the compounds contribute to the antioxidative activity. The results of the assays showed that, on average, ca. 27% of the original antioxidative capacity remained 24 weeks after the onset of the storage treatment, while a large variation (2-95% of the original capacity remaining) was found between assays, seasons, and bark layers. Inner bark preserved its activities longer than outer bark, and intact bark attached to timber is expected to maintain its activities longer than a debarked one. Thus, to ensure prolonged quality, no debarking before storage is suggested: outer bark protects the inner bark, and debarking enhances the degradation.
PDF(Sci-hub)