Effects of industry-inspired storage conditions on the contents of hydrophilic extractives and polyphenols in Silver fir (Abies alba Mill.) bark

Hrovatič, Peter (author), Levanič, Tom (author), Oven, Primož (author), Poljanšek, Ida (author), Vek, Viljem (author)

Silver fir bark (Abies alba Mill.) is an underutilized renewable resource containing valuable extractives and polyphenols of industrial importance. This study compared the influence of two storage methods on the extraction of total hydrophilic extractives content (TEC) and total polyphenols content (TPC) from silver fir bark samples. Bark samples were collected from two storage types: bark left on stem sections and stored under cover (B-D), and mechanically removed industrial bark stored outdoors (B-IS), over a 12-month period with monthly sampling and extraction, followed by measurements of TEC and TPC using gravimetric and spectrophotometric methods. B-D samples showed no statistically significant decrease in TEC or TPC during one year of storage, while B-IS samples exhibited substantial losses, with TEC decreasing by more than half (50.82%) and TPC by 65.68%, most rapidly within the first 3 months when precipitation-driven leaching and degradation processes were obviously most pronounced. These results demonstrate that bark removed before storage is much more susceptible to degradation and leaching of the hydrophilic extractives than bark retained on logs, confirming that mechanical disintegration and exposure to weathering accelerate the loss of valuable extractives and polyphenols. A strong TEC–TPC correlation (r = 0.67–0.81, p < 0.0001) provides a practical methodological approach for rapid biomass quality screening. Overall, the findings offer quantitative guidance for optimizing debarking timing and storage practices to preserve extractive yield and enhance the efficiency of bark-based biorefinery processes.

• Language: English
• Keywords: silver fir bark, Abies alba Mill., extractives, polyphenols, biomass storage, chemical analysis, circular bioeconomy, bioactive compounds, forest-based by-products
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 18 str.
• Numbering: Vol. 17, issue 2, [article no.] 280
• PID: 20.500.12556/RUL-180290
• UDC: 630*8
• ISSN on article: 1999-4907
• DOI: 10.3390/f17020280
• COBISS.SI-ID: 270550787
• Publication date in RUL: 05.03.2026

Record is a part of a journal

• Title: Forests
• Shortened title: Forests
• Publisher: MDPI
• ISSN: 1999-4907
• COBISS.SI-ID: 3872166

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: skorja bele jelke, ekstraktivi, polifenoli, skladiščenje biomase, krožno gospodarstvo, bioaktivne spojine