Produced in many world’s countries at over 1 million tonne/year rate by extraction of certain woods and barks with boiling water, tannin is a class of high molecular weight biophenols increasingly used in a number of industries. This study offers a new bioeconomy insight into an old natural product that, we argument in this study, will play a crucial role in the development of the bioeconomy of forest regions. After providing an updated picture of key economic and production aspects, we show how flourishing research on tannin’s biological activity and technological applications has revealed many new properties which are likely to drive significant growth in demand in the near and mid-term future. The study concludes with selected recommendations for bioeconomy scholars and for policy-makers based in forest areas.

The exploitation of bio-based foams implies an increase in the use of renewable biological resources to reduce the rapid consumption of petroleum-derived resources. Both tannins and furfuryl alcohol are derived from forestry resources and are therefore considered as attractive precursors for the preparation of tannin-furanic foams. In addition, toughening modification of tannin-furanic foams using polyvinyl alcohol (PVOH) resulted in a more flexible network-like structure, which imparts excellent flexibility to the foams with acquirement of relative properties that are even close to those of polyurethane foams, which are the most used polymers for fabrication of insoles for athletes. In addition, the addition of PVOH did not affect the thermal insulation of the foams, resilience and elongation at break, while reducing the brittleness of the samples and improving the mechanical properties. Also the observation of the morphology of the foam indicated that the compatibility between PVOH and tannin-furanic resin is good, and the cured foam does not show fragmentation or collapse, while the bubble pore structure is uniform. The developed flexible foam derived from biomass resources endowed the foam good thermal insulation properties and high mechanical properties, and the samples exhibited suitable physical parameters to be used as flexible insoles for athletes.

Maize silage is produced to alleviate forage shortage on dairy animals, particularly during the dry season. Microorganisms play a significant role in silage fermentation and thus determine the silage quality. Therefore, modulation of microorganisms in silage may help prohibit undesired bacteria and improve silage quality. Hence, this study evaluated the effects of tannin extract as an additive on fermentative quality, aerobic stability and microbial composition of maize silage. Therefore, a mini-silo experiment of maize with five treatments was conducted for 75 days. The results showed that additives modulate silage microorganisms. In addition, tannin extract reduced certain silage bacteria while promoting others. However, this is without affecting the silage’s fermentative quality and aerobic stability. All silage fermented well with a pH below 4.2. Tannin extract improved dry matter recovery of silage while reducing silage weight loss. Furthermore, tannin extract suppressed the establishment of undesired bacteria, such as genera Dysgonomonas, Gluconacetobacter and Clostridium, while promoting desirable bacteria, such as genera Lactobacillus and Weissella, which attributed to silage quality. Therefore, it is concluded that tannins can be strategically used as silage additives to modulate microbial composition of silage and improve silage quality by promoting the dominance of desirable bacteria in silage.