August 16, 2024 | Food Hydrocolloids |
The innovative use of dragon fruit stem extract (DSE), an agricultural byproduct, in synthesizing silver nanoparticles (AgNPs) and incorporating them into chitosan-based composite films was explored in a study by researchers from Vietnam National University and Ho Chi Minh City University of Technology. This represents the first reported use of DSE both as a reducing agent for AgNP synthesis and as a component in chitosan film formulations.
The researchers optimized AgNP synthesis (120 minutes, DSE/AgNO3 ratio of 20/30) and integrated these nanoparticles into the film. Various analytical techniques, including SEM, EDS, FTIR, XRD, and HR-TEM, were employed to characterize the film's structure and properties. The composite films demonstrated significant improvements in tensile strength, achieving up to 24.85 MPa, and exhibited excellent antimicrobial activity, eliminating over 99.99% of S. aureus and E. coli within six hours. Additionally, the films showed high antioxidant activity (up to 89.28%) and effective food preservation capabilities, reducing strawberry weight loss to 44.58% and extending shelf life to five days.
The study concludes that the composite film, with silver migration compliant with EFSA and ECHA standards, is suitable for food packaging applications, offering a sustainable and functional solution to agricultural waste utilization and food preservation challenges.
