0000000000381574
AUTHOR
Maija Hujala
Behaviour of Extractives in Norway Spruce (Picea abies) Bark during Pile Storage
The current practices regarding the procurement chain of forest industry sidestreams, such as conifer bark, do not always lead to optimal conditions for preserving individual chemical compounds. This study investigates the standard way of storing bark in large piles in an open area. We mainly focus on the degradation of the most essential hydrophilic and hydrophobic extractives and carbohydrates. First, two large 450 m3 piles of bark from Norway spruce (Picea abies) were formed, one of which was covered with snow. The degradation of the bark extractives was monitored for 24 weeks. Samples were taken from the middle, side and top of the pile. Each sample was extracted at 120 °C with both n-h…
The effect of thermal drying on the contents of condensed tannins and stilbenes in Norway spruce (Picea abies [L.] Karst.) sawmill bark
Norway spruce (Picea abies (L.) Karst.) bark contains marked amounts of polyphenolic compounds. Condensed tannins (CTs) and stilbenes show commercial potential as antioxidants, antimicrobials, preservatives in food and cosmetic applications, technochemical products, and pharmaceuticals. Storing of bark before the conversion process leads to substantial losses of extractives compounds. In the present study, the potential of thermal drying for maintaining extractives content was assessed based on an experiment in which bark samples were dried in convection kilns at 40, 50, 60, and 70 °C temperatures. The development of CTs and stilbene contents and CT degradation were followed for 28–34 h. CT…