Fate of Antioxidative Compounds within Bark during Storage: A Case of Norway Spruce Logs
| Autor: | Janne Kaseva, Tuula Jyske, Patrik Eklund, Juha Nurmi, Hanna Brännström, Eelis Halmemies, Lucas Lagerquist, Jan-Erik Raitanen, Tytti Sarjala, Jarkko Hellström |
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| Přispěvatelé: | Department of Chemistry |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
bark Time Factors antioxidant Antioxidant medicine.medical_treatment 116 Chemical sciences Pharmaceutical Science WOOD 01 natural sciences Antioxidants Analytical Chemistry Drug Discovery condensed tannin chemistry.chemical_classification PLASMA biology PICEA-ABIES BARK Horticulture STILBENES Proanthocyanidin Chemistry (miscellaneous) visual_art Plant Bark visual_art.visual_art_medium Molecular Medicine ORAC Bark Seasons EXTRACTION Softwood forestry side-stream timber Raw material complex mixtures Article Gas Chromatography-Mass Spectrometry CAPACITY lcsh:QD241-441 lcsh:Organic chemistry medicine Proanthocyanidins Picea Physical and Theoretical Chemistry TANNINS Plant Extracts 010405 organic chemistry Organic Chemistry Glycoside Picea abies 15. Life on land biology.organism_classification 0104 chemical sciences stilbene YIELD chemistry 13. Climate action FRAP Condensed tannin 010606 plant biology & botany |
| Zdroj: | Molecules, Vol 25, Iss 4228, p 4228 (2020) Molecules Volume 25 Issue 18 |
| ISSN: | 1420-3049 |
| DOI: | 10.3390/molecules25184228 |
| Popis: | 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&ndash 7% of the original stilbene amount and ca. 30&ndash 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&ndash 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. |
| Databáze: | OpenAIRE |
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