A comparative study of flavonoid contents and antioxidant activities of supercritical CO2 extracted pine barks grown in different regions of Turkey and Germany

摘要

Utilization of renewable resources is gaining more emphasis and large quantities of solid wastes are produced by the forestry industry. However, there is a significant lack of transformation of such wastes into potentially novel products. The barks of various Pinus species from different regions of Turkey (P. pinea, P. sylvestris, P. nigra) and Germany (P. parviflora, P. ponderosa, P. sylvestris, P. nigra) were extracted by supercritical CO2 extraction. Different sources of variability including location and species were evaluated for their active constituents, (-)-catechin, (-)-epiatechin, (-)-catechin gallate, and taxifolin, applying HPLC, radical scavenging activities (RSA), and total phenol analysis. The total amounts of flavan-3-ols (9.916 mg/g) were the highest in P. pinea extract harvested from Aydin, having the hottest climate and longest duration of sun (P < 0.01). In addition, P. pinea had the highest RSA (81.0 %) and total phenol value (83.0 mg GAE/g).