Enhancing biomass-derived oleoresin yield and quality through chemical stimulants and tapping methods in Pinus roxburghii Sargent

Oleoresin derived from pine trees is a renewable forest biomass product with diverse industrial and energy applications. In India, Pinus roxburghii Sargent (Chir Pine) is the main commercial source for oleoresin tapping and offers significant potential for sustainable biomass utilization. This study was conducted in Western Himalayan forests to assess the effects of chemical stimulants and tapping methods on both yield and quality of pine oleoresin. Forty-two trees were engaged in two different tapping methods, i.e., the borehole and rill method, and six different chemical stimulants as treatments. Results indicated the maximum oleoresin yield was obtained from treatment T₇ (20 % H₂SO₄ + 20 % HNO₃), with the rill method yielding the highest seasonal output (3694.08g/tree/season). However, oleoresin yield per borehole and turpentine content, an important biofuel precursor, were higher with the borehole method, which also proved less detrimental to tree health compared to the rill method, indicating its suitability for sustainable biomass extraction. The rill method, conversely, produced resin with higher rosin content and density. Quality analysis revealed that the chemical composition of oleoresin, critical for bioenergy and bioproduct manufacturing, varied according to both stimulant and tapping method used. Additionally, the borehole method and chemical stimulants accelerated wound healing, preserving tree vitality for biomass accumulation. Overall, these findings highlighted the potential of optimizing tapping methods and chemical stimulants for improving the quality of oleoresin as a biomass-based renewable resource, supporting its role in the bioenergy and bioproduct sectors.