• Fracture toughness of Fructus Gardeniae is strongly dependent on moisture content, with higher moisture leading to increased toughness.
• The integration of digital image correlation and finite element analysis provides a comprehensive understanding of fracture mechanisms in herbal materials.
• Microstructural features, such as cell wall thickness and porosity, play a critical role in determining the mechanical integrity of Fructus Gardeniae.
• The findings offer a scientific basis for optimizing drying and processing conditions to preserve the quality of traditional Chinese medicines.