By embedding these natural compounds into chitosan aerogel spheres, the study significantly enhanced their antibacterial efficacy, offering a novel way to valorize agricultural waste and develop plant-based antimicrobial products.
Carya cathayensis is a major nut crop cultivated in Zhejiang and Anhui provinces, producing nutritious kernels rich in beneficial lipids and polyphenols. However, large-scale production generates substantial husk waste, which is challenging to degrade naturally. These husks contain valuable triterpenoids known for their antibacterial properties, yet their poor water solubility limits practical applications. Ultrasound-assisted extraction combined with surfactants has emerged as an efficient, eco-friendly strategy to enhance the release of bioactive plant compounds. Meanwhile, chitosan aerogels, with their highly porous structures and natural antimicrobial features, have shown promise in improving the delivery and efficacy of hydrophobic compounds such as triterpenoids.
A study (DOI: 10.48130/fia-0025-0011) published in Food Innovation and Advances on 12 March 2025 by Zisheng Luo’s team, Zhejiang University, provides an innovative method for repurposing C. cathayensis husks into high-value antibacterial agents, contributing to sustainable agricultural waste management.
The researchers first optimized a surfactant-mediated ultrasound-assisted extraction (UAE) process using response surface methodology, achieving a high triterpenoid yield of 33.92 ± 0.52 mg UAE/g DW. Span-80 surfactant significantly improved extraction efficiency, while careful control of temperature, extraction time, and solvent-to-solid ratio maximized yield without degrading bioactive compounds. Following extraction, triterpenoids were purified using AB-8 macroporous resin, achieving a 4.3-fold increase in purity. To improve the application potential of the hydrophobic triterpenoids, mesoporous chitosan aerogel spheres were fabricated and characterized, displaying a specific surface area of 97.1 m²/g and high adsorption capacity (123.5 ± 0.71 mg/g). Infrared spectroscopy and thermogravimetric analysis confirmed successful triterpenoid loading and enhanced thermal stability. Antimicrobial assays showed that chitosan aerogel spheres loaded with CCSH triterpenoids significantly inhibited the growth of Escherichia coli and Staphylococcus aureus more effectively than either component alone. Notably, S. aureus was more sensitive to the treatment, likely due to differences in cell wall structures. These results demonstrate that combining chitosan aerogels with triterpenoid extracts not only improves compound solubility but also achieves a synergistic antibacterial effect, suggesting a promising strategy for developing plant-based antimicrobial materials from agricultural by-products.
In summary, this study established an eco-friendly method combining surfactant-assisted ultrasound extraction and resin purification to efficiently isolate antibacterial triterpenoids from Carya cathayensis husks. By embedding the purified triterpenoids in mesoporous chitosan aerogel spheres, their solubility and antibacterial activity were significantly enhanced, achieving a synergistic inhibitory effect against Escherichia coli and Staphylococcus aureus. Scaling up aerogel production and exploring multi-functional loading strategies could unlock broader applications in food safety, healthcare, and sustainable materials development.
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References
DOI
10.48130/fia-0025-0011
Original Source URL
https://doi.org/10.48130/fia-0025-0011
Funding information
This research is funded by the Key Research and Development Program of Zhejiang Province (2023C02042), China.
About Food Innovation and Advances
Food is essential to life and relevant to human health. The rapidly increasing global population presents a major challenge to supply abundant, safe, and healthy food into the future. The open access journal Food Innovation and Advances (e-ISSN 2836-774X), published by Maximum Academic Press in association with China Agricultural University, Zhejiang University and Shenyang Agricultural University, publishes high-quality research results related to innovations and advances in food science and technology. The journal will strive to contribute to food sustainability in the present and future.