Abstract
Bark is considered as waste generated by wood processing industries. Bark is being used for horticulture applications and energy production, but due to its complex structure, bark can become biorenewable source. It is rich in high add-value compounds, as bioactive compounds, which are used in medicine, nutrition or personal care products. The most used extraction method for this bio-compounds is the conventional (liquid extraction), but in recent years others are being investigated. In this work conventional extraction (CE), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) were optimized to obtain the highest extraction yield (%). In the optimal point of the design, total phenolic content (TPC) and total flavonoids content (TFC) of the extract of each method were determined. Their antioxidant capacity was also measured using 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assay (ABTS) and ferric reducing antioxidant power (FRAP) assay. The best extraction yield (%) as well as the highest antioxidant capacities were obtained with microwaves. The results showed the potential of the bark of Larix Decidua as source of bioactive compounds. Using microwaves for extraction could save energy and reduce the processing time.
