Date of Publication

8-16-2025

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Advisor

Joel E. Garcia

Defense Panel Member

Francis M. dela Rosa
Joan Candice V. Ondevilla

Abstract (English)

Agarwood, a highly valued fragrant resin used in perfumery and medicine, has a slow unpredictable natural formation, limiting sustainable production. This study explored the chemical inoculation of ZnO-PEG NPs, KCl, and FeCl3 in the stimulation of artificial agarwood production in Aquilaria malaccensis trees in Tanza, Philippines. ZnO-PEG NPs were synthesized via the co-precipitation method and characterized by their optical, functional, morphological, and structural properties. UV-Visible spectra showed a characteristic absorption peak at 370 nm. FTIR spectra presented the functional groups of the PEG 4000 coating and the synthesized ZnO-PEG NPs. XRD revealed well-defined peaks of ZnO’s hexagonal wurtzite structure, and a crystallite size of 20.44 nm. FESEM analysis revealed the irregular, quasi-spherical morphology with an average particle size of 284 ± 114 nm. HR-TEM analysis exhibited spherical nanoparticles with an average core size of 29.74 nm. SEM-EDS showed 39.88% zinc, 48.70% oxygen, and 11.42% carbon, confirming the presence of a zinc oxide core and PEG coating. TEM-EDX primarily detected the PEG layer with 90.2% carbon and 3.2% oxygen, validating the effective surface modification of the nanoparticles. Sensory evaluations of the bark samples across a 115-day span confirmed that those inoculated with KCl and FeCl3 exhibited the most intense discoloration for their external and core appearances, while the samples inoculated with ZnO-PEG NPs are still in their initial stages of resin formation. HPLC analysis revealed that the bark samples inoculated with FeCl3 and KCl showed a more complex metabolic profile compared to their healthy counterparts. GC-MS analysis confirmed sesquiterpene and chromone formation in all chemically inoculated barks by D-115. These indicate that targeted chemical inoculation can induce key agarwood metabolites within a controlled timeframe, supporting more sustainable and predictable resin production.

Keywords: Aquilaria malaccensis; agarwood; ZnO-PEG nanoparticles; chemical inoculation; ferric chloride; potassium chloride

Abstract Format

html

Abstract (Filipino)

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Abstract Format

html

Language

English

Format

Electronic

Keywords

Aquilaria malaccensis; Ferric chloride; Potassium chloride

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Embargo Period

8-19-2026

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Available for download on Wednesday, August 19, 2026

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