Bioactive Compounds from Norway Spruce Bark: Comparison Among Sustainable Extraction Techniques for Potential Food Applications

Abstract

Picea abies (L.) Karst, (Norway spruce) bark, generally considered as wood industry waste, could potentially be used as a valuable source of antioxidants for food applications. In this study, supercritical fluid extraction (SFE), pressurized liquid extraction (PLE), and ultrasound-assisted extraction (UAE) were carried out in order to recover bioactive compounds from bark of Norway spruce. Obtained results show that PLE with ethanol as solvent was the most effective method for extracting total flavonoid compounds (21.14 ± 1.42 mg quercetin g−1 sample) and consequently exerted the highest antioxidant activity measured by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (257.11 ± 13.31 mg Trolox g−1 sample). On the other hand, UAE extract contained the maximum phenolic concentration (54.97 ± 2.00 mg gallic acid g−1 sample) and the most interesting antioxidant activity measured by the ferric-reducing antioxidant power (580.25 ± 25.18 µmol FeSO4 g−1 sample). Additionally, PLE and UAE have demonstrated great efficiency in the extraction of trans-resveratrol, quantified by HPLC (0.19 and 0.29 mg trans-RSV g−1 sample, respectively).

Investigation of Total Phenolic Content and Antioxidant Activities of Spruce Bark Extracts Isolated by Deep Eutectic Solvents

“…Value-added substances and compounds are isolated from biomass by extraction techniques using predominantly water and common organic solvents, and, to a minor extent, eco-friendly green solvents represented by deep eutectic solvents [13]. To reach high extraction yield of target compounds, various extraction techniques have been developed, the most frequently used being supercritical fluid extraction, pressurized liquid extraction, and ultrasound-assisted extraction [7].…”

“…The effectiveness of the extraction is quantified through total extract yield, total phenolic content (TPC), total flavonoid content, and total antioxidant capacity [52]. Particular attention is devoted to trans-resveratrol (trans-RSV), which is considered a powerful compound capable to improve health and prevent chronic diseases in humans, protecting against some neurodegenerative diseases, obesity and diabetes, high blood pressure, as well as cancer and osteoporosis [7]. In Table 1 This paper is devoted to three mutually overlapping research topics: softwood bark as the object of processing; polyphenols as the extracted antioxidants; and deep eutectic solvents as extractants.…”

“…Thus, Norway spruce (Picea abies [Karst.]) bark can be regarded as a largely available source of condensed polyphenols in Europe [5][6][7][8][9][10]. Meanwhile, the rationale behind the choice of polyphenols lies in their mentioned properties and usability.…”

Phytochemical Profile and Biological Effects of Spruce (Picea abies) Bark Subjected to Ultrasound Assisted and Microwave-Assisted Extractions

“…A previous study also highlighted the AC of ethanolic spruce bark extracts obtained by UAE, tested with the ABTS reagent [ 54 ]; however, no studies measuring the AC of spruce bark extracts obtained by MAE with the ABTS assay, were found. For both assays (DPPH and ABTS), the results of this study and those of the baseline studies, could not be directly compared because of the different methodologies used and the different ways to express the final results.…”

Natural Antioxidants: Innovative Extraction and Application in Foods

“…Chapter 10 is titled “Bioactive Compounds from Norway Spruce Bark: Comparison among Sustainable Extraction Techniques for Potential Food Applications” [ 10 ]. This is a great chapter comparing different techniques to extract antioxidants from Norway spruce bark ( Picea abies (L.) Karst), a wood industry waste.…”