Forest Research Centre

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First Chemical Profile Analysis of Acacia Pods

Publication . Pedro, Soraia; Fernandes, Tiago A.; Luís, Ângelo; Antunes, A M M; Gonçalves, J. C.; Gominho, Jorge; Gallardo, Eugenia; Anjos, Ofélia

This study intended to evaluate the potential industrial applications of various Acacia species (Acacia melanoxylon, Acacia longifolia, Acacia cyclops, Acacia retinodes, Acacia pycnantha, Acacia mearnsii, and Acacia dealbata) by examining their chemical composition, antioxidant, and antimicrobial properties. Using high-resolution mass spectrometry, a comprehensive analysis successfully identified targeted compounds, including flavonoids (flavonols/flavones) and phenolic acids, such as 4-hydroxybenzoic acid, p-coumaric acid, and ellagic acid. Additionally, p-coumaric acid was specifically identified and quantified within the hydroxycinnamic aldehydes. This comprehensive characterization provides valuable insights into the chemical profiles of the studied species. Among the studied species, A. pycnantha exhibited a higher concentration of total phenolic compounds, including catechin, myricetin, quercetin, and coniferaldehyde. Furthermore, A. pycnantha displayed notable antibacterial activity against K. pneumoniae, E. coli, S. Typhimurium, and B. cereus. The identified compounds in Acacia pods and their shown antibacterial activities exhibit promising potential for future applications. Moreover, vibrational spectroscopy was a reliable method for distinguishing between species. These significant findings enhance our understanding of Acacia species and their potential for various industrial applications.

2023Journal article

Open access

Insights into Acacia spp.: A Comprehensive Phytochemical Analysis for its Potential Industrial Applications

Publication . Pedro, Soraia Inês; Anjos, Ofélia Maria Serralha dos; Alba, Maria Eugénia Gallardo; Gominho, Jorge Manuel Barros D'Almeida

This study explored the bioactive and nutritional potential of various Australian Acacia species, recognized as problematic invasive plants in several regions worldwide. The research aimed to develop analytical methods to identify and quantify bioactive compounds in different biomass fractions of these plants. Initially, flowers of Acacia dealbata, Acacia mearnsii, and Acacia retinodes were harvested and analyzed, focusing on their chemical composition, antioxidant potential, and enzyme inhibition activities. The analysis included the identification of phenolic compounds using High-performance liquid chromatography coupled to a diode array detector (HPLC/DAD), as well as Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR) and Fourier Transform Raman Spectroscopy (FT-RAMAN). The results indicated that extracts obtained during the early flowering stage exhibited higher bioactivity, likely due to the presence of chalcones, suggesting potential therapeutic applications, including treatments for dementia, diabetes, and microbial infections. Subsequently, the study evaluated the phenolic profile, antioxidant, and antimicrobial properties of seed pods from several Acacia species, including A. melanoxylon, A. longifolia, and A. cyclops. Liquid chromatography coupled with high-resolution mass spectrometry (LC-ESI-HRMS/MS) successfully identified key flavonoids, with A. pycnantha and A. cyclops displaying the highest concentrations of total phenolic compounds. The seed pod extracts demonstrated significant antibacterial activity, particularly against Klebsiella pneumoniae and Bacillus cereus, indicating potential for future industrial applications. The study also explored the potential of Acacia seed pods as a source of nutrients for animal feed and soil fertilization. Notably, A. retinodes seed pods were rich in proteins, fibers, and minerals such as potassium, calcium, and magnesium, suggesting their suitability for mineral supplementation, although further studies are required to assess bioaccessibility and toxicity. Finally, the nutritional composition and mineral content of leaves from eight Acacia species were analyzed to evaluate their potential as ruminant feed and mineral sources for soils. The extracts were found to be non-cytotoxic in Caco-2 cells, indicating their suitability as an alternative food source for animals. The leaves also exhibited high levels of proteins, fibers, and minerals, particularly calcium, phosphorus, and potassium. In conclusion, this research demonstrated that Acacia species contain promising bioactive compounds with significant therapeutic potential, particularly in antioxidant and antimicrobial applications. Additionally, the nutritional and mineral composition of Acacia species suggests promising applications in animal nutrition and soil fertilization. These findings pave the way for the sustainable and multifunctional use of Acacia species, contributing to mitigating their ecological impact while exploring their economic value.

2025-05Doctoral thesis

Embargoed access

Insect-based chitin and chitosan from whole body sources and rearing by-products: extraction, physicochemical, structural and bioactivity characterisation

Publication . Navarro, Pedro; Ribeiro, José Carlos Reis ; Luís, Ângelo Filipe Santos ; Domingues, Fernanda; Anjos, Ofélia; Cunha, Luis

Fractionation of edible insects and their rearing by-products can lead to expanded industrial applications and extraction of value-added products. The main goal of this study was to extract chitin and synthesise chitosan from three different insect sources – Tenebrio molitor larvae, adult Acheta domesticus and A. domesticus rearing by-products (legs and wings). Furthermore, the physicochemical, structural, and bioactive properties of insectderived chitin and chitosan were characterised and compared to commercial crustacean-based samples. Chitin was isolated from defatted sources through chemical hydrolysis followed by decolourisation and was deacetylated with a strong alkaline solution to synthesise chitosan. Notably, A. domesticus rearing by-products yielded the highest chitin and chitosan content. Chitin and chitosan derived from insects exhibited physicochemical and structural characteristics consistent with the α-polymorphic form, similar to the commercial samples. Differences were found in surface morphology, with insect-derived samples presenting large and irregular flakes and porosity, while the crustacean-derived samples presented irregularly arranged fibres and a more regular and smoother surface. As for antioxidant activity, although all chitosan samples demonstrated poor DPPH radical scavenging activity, this study showed for the first time that insect-derived chitosan presents lipid peroxidation inhibition ability. All chitosan samples presented antimicrobial activity against different pathogenic bacteria, with K. pneumoniae being the most susceptible strain. Nevertheless, there is potential for enhancement of the biological properties through modifications on the molecular weight and deacetylation degree. This research introduces the potential of cricketrearing by-products as sustainable sources of chitosan with functional bioactive properties.

2025-01-14Journal

Restricted access