resumo
The development of multifunctional materials from agrifood residues supports circular bioeconomy strategies by reducing waste and promoting renewable feedstocks. This study investigates rejected rice dust (RD) and colored rice (CR), two starch-rich rice processing by-products, as alternative sources for natural starch-based bioplastics, using purified rice starch (PRS) as a benchmark. RD and CR contained 79.9% and 82.9% total carbohydrates (48.6% and 51.8% starch), versus 98.3% carbohydrates and 70.2% starch in PRS. CR exhibited the highest amylose (29.5%) and phenolic content (20.9 mg GAE/100 g), compared to RD (21.3%; 8.8 mg GAE/100 g) and PRS (15.8%; 2.3 mg GAE/100 g). Gelatinization peak temperatures are elevated in RD (74.2 degrees C) and CR (73.9 degrees C) versus PRS (66.7 degrees C). RD-based films showed mechanical strength (5.4 MPa) and modulus (146 MPa) comparable to PRS (5.5 MPa; 175 MPa), while CR-based films have lower modulus (53 MPa) but greater elongation at break (20.2%). Contact angles are highest in CR (119 degrees), followed by PRS (102 degrees) and RD (70 degrees). Antioxidant activity reached 88% (CR), 33% (RD), and 10% (PRS). Only CR-based films provided UV-B protection. These results highlight RD and CR as renewable matrices for producing environmentally sustainable, functionally enhanced starch-based materials for packaging and coating applications.
palavras-chave
PHYSICOCHEMICAL PROPERTIES; FILM PROPERTIES; GLYCEROL; BEHAVIOR; GRANULE; ACIDS
categoria
Science & Technology - Other Topics; Materials Science
autores
Brites, P; Luis, J; Kapusniak, K; Wojcik, M; Nunes, C; Coimbra, MA; López-Rubio, A; Oliveira, M; Ferreira, P; Gonçalves, I
nossos autores
Cláudia Nunes
Investigador Auxiliar
Idalina José Monteiro Gonçalves
Investigador Auxiliar
J. Martinho Oliveira
Professor Coordenador
Jorge Louro Luís
Técnico de Laboratório
Paula Celeste da Silva Ferreira
Investigador Coordenador
Paulo Brites
Estudante de doutoramentoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G4 - Materiais Renováveis e Economia Circular
Projectos
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)
agradecimentos
This work was developed within the scope of the projects CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) and LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) and LAQV-REQUIMTE (UIDB/50006/2020; UIDP/50006/2020), financed by National funds through the FCT/MCTES (PIDDAC). FCT is also thanked for Individual Call to Scientific Employment Stimulus (IG, ), and PhD grant (PB, UI/BD/151143/2021). CN is grateful to Portuguese national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19 (DL 57/2016/CP1482/CT0031). Acknowledgement is also due to Qualiriso, Lda for providing RD and CR. The Accreditation of IATA-CSIC as Center of Excellence Severo Ochoa CEX2021-001189-S funded by MCIN/AEI/ 10.13039/501100011033 is also fully acknowledged.