abstract
This study explores an innovative approach to transforming leftover bread, a major source of food waste, into eco-friendly packaging materials. Using the ultrasound-assisted hydrothermal method and a chemical-free approach, carbon quantum dots (QDs) and starch (ST) were derived from leftover bread. Smart films were then developed by blending ST, glycerol, and QDs (1 % or 3 wt% of ST) and alizarin (AL), using solvent casting. QDs exhibited UV-barrier, photoluminescent, antioxidant activity (79.13 % DPPH radical scavenging), and low toxicity to murine fibroblasts below 200 mu g/mL. Their inclusion improved film plasticity, increased elongation by 59 %, enhanced the water vapor barrier, and raised surface hydrophobicity. The films showed antibacterial effects, inhibiting E. coli by 47.77 % and S. aureus by 97.82 %. Interactions between QDs and AL led to a reduced visual color change in the colorimetric films in response to ammonia and acetic acid vapors; however, they enhanced the films' fluorescent properties. This study introduces a sustainable biorefinery strategy to upcycle bread waste into smart packaging, reducing waste and contributing to food spoilage monitoring.
keywords
FABRICATION; ALIZARIN
subject category
Agriculture
authors
Qazanfarzadeh, Z; Baptista, H; Nunes, C; Kumaravel, V
our authors
Cláudia Nunes
Assistant Researcher
Hélder Duarte de Magalhães Oliveira Baptista
PhD StudentProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This research was completed with the support of the European Consortium of Innovative Universities (ECIU) Researcher Mobility Fund. In addition, this work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020) , UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) , financed by national funds through the FCT/MCTES (PIDDAC) . H.B. also thanks FCT for the PhD fellowship 2022.11211.BD.