Development of natural browsing repellent to protect garden and forest plantings
Dehmani, Chaima (2025)
Diplomityö
2025
School of Engineering Science, Kemiantekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2025090294069
https://urn.fi/URN:NBN:fi-fe2025090294069
Tiivistelmä
Browsing by moose and roe deer causes significant damage to Finnish forests and garden vegetation. The current synthetic repellents present environmental and economic drawbacks, while existing natural repellents show limitations in persistence and effectiveness. Hence, developing natural alternatives from locally available biomass offers a sustainable approach to reduce animal browsing while valorising agricultural and forestry side streams.
This study aims to characterise cruciferous vegetables, birch and pine bark, and sheep wool grease as potential raw materials for natural repellent formulations. Extraction of bioactive compounds was carried out by ultrasound-assisted extraction for cruciferous biomass, and by Soxhlet extraction for wood barks and sheep wool grease. The obtained extracts were characterised with UV-vis spectroscopy, FTIR, GC–MS, and HPTLC. Total phenolic contents of cruciferous biomass extracts were also measured.
Results indicate that broccoli showed the most promising deterrent potential among crucifers with high potentially sulforaphane- and glucosinolate-related absorbance (196 and 227 nm) and optimised release of sulphur volatiles after freeze pretreatment (at -20 °C) with UAE at 50 °C. Birch bark extracts contained triterpenoids such as betulin (with UV absorbance at 200–230 nm, and infrared peak at 887 cm⁻¹). Triterpenoids of birch bark are characterised by bitterness and persistence properties, whereas pine bark extraction resulted in higher contents of lipophilics (64 mg/g) consisting of resin acids, fatty acids, and esterified lipids which are associated with odour deterrence. The extracted sheep wool grease contained 55–60 wt% free fatty acids/alcohols, 10–20 wt% sterols, and 10–15 wt% wax esters, which makes it more persistent due to its film-forming hydrophobicity compared to commercial Trico repellent, which contained 99 wt% triglycerides.
These findings demonstrate that extracts of cruciferous biomass, bark samples, and wool grease together provide complementary active ingredients for the formulation of animal browsing repellent.
This study aims to characterise cruciferous vegetables, birch and pine bark, and sheep wool grease as potential raw materials for natural repellent formulations. Extraction of bioactive compounds was carried out by ultrasound-assisted extraction for cruciferous biomass, and by Soxhlet extraction for wood barks and sheep wool grease. The obtained extracts were characterised with UV-vis spectroscopy, FTIR, GC–MS, and HPTLC. Total phenolic contents of cruciferous biomass extracts were also measured.
Results indicate that broccoli showed the most promising deterrent potential among crucifers with high potentially sulforaphane- and glucosinolate-related absorbance (196 and 227 nm) and optimised release of sulphur volatiles after freeze pretreatment (at -20 °C) with UAE at 50 °C. Birch bark extracts contained triterpenoids such as betulin (with UV absorbance at 200–230 nm, and infrared peak at 887 cm⁻¹). Triterpenoids of birch bark are characterised by bitterness and persistence properties, whereas pine bark extraction resulted in higher contents of lipophilics (64 mg/g) consisting of resin acids, fatty acids, and esterified lipids which are associated with odour deterrence. The extracted sheep wool grease contained 55–60 wt% free fatty acids/alcohols, 10–20 wt% sterols, and 10–15 wt% wax esters, which makes it more persistent due to its film-forming hydrophobicity compared to commercial Trico repellent, which contained 99 wt% triglycerides.
These findings demonstrate that extracts of cruciferous biomass, bark samples, and wool grease together provide complementary active ingredients for the formulation of animal browsing repellent.