resumo
Locust bean milling dust (LBMD) is an agrifood byproduct rich in proteins and polysaccharides able to form hydrophilic, flexible, and antioxidant bioplastics. Aiming a broad application for LBMD-based bioplastics, in this work, it was hypothesized that glycerol, milled eggshells, or genipin amount fine-tuning can originate rigid and hydrophobic antioxidant LBMD-based materials. With 20 g/100 g glycerol, the films became more 10-fold stiff (Young's modulus of 253 MPa), 1.7-fold hydrophobic (water contact angle of 109 degrees), and 22-fold resistant to water vapor (5 pg/Pa.s.m) than pristine films (Young's modulus of 26 MPa, water contact angle of 64 degrees, and water vapor permeability of 109 pg/Pa.s.m), keeping their yellowish color and transparency. Apart from stiffness that did not change, this profile was also evidenced when 1 g/100 g milled eggshells were incorporated, increasing hydrophobicity 1.5 times and decreasing water vapor permeability 1.6 times. The use of 0.03 g/100 g genipin conferred a blue color to LBMD-based bioplastics and more 5-fold rigidity, 1.7-fold hydrophobicity, and 2.2-fold water vapor barrier. Therefore, rigid, water tolerant, and antioxidant LBMD-based bioplastics can be developed by tailoring glycerol, milled eggshells, or genipin amount, with 20 g/100 g glycerol or 0.03 g/100 g genipin as best conditions to improve these features.
palavras-chave
BIODEGRADABLE EDIBLE FILM; MECHANICAL-PROPERTIES; PLASTICIZER-TYPE; PROTEIN FILMS; STARCH FILMS; CHITOSAN; POWDER; HYDROPHILICITY; ACID; FOOD
categoria
Food Science & Technology
autores
Lopes, J; Ferreira, P; Coimbra, MA; Gonçalves, I
nossos autores
Grupos
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)
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
Projeto de Investigação Exploratória: Paula Ferreira (IF_Paula Ferreira)
agradecimentos
The authors want to thank the University of Aveiro and FCT/MCTES for the financial support of LAQV-REQUIMTE (UIDB/50006/2020 and UIDP/50006/2020) and CICECO Aveiro Institute of Materials (UIDB/50011/2020, UIDP/50011/2020, LA/P/0006/2020) research units. The authors also acknowledge to Industrial Farense, Lda., Derovo - Derivados de Ovos, S.A, and Isolago-Industria de Plasticos, S.A. for providing locust bean byproduct, eggshells, and commercial calcium carbonate, respectively. FCT is also thanked for the Investigator FCT program (PF, IF/00300/2015), the Individual Call to Scientific Employment Stimulus (IG, CEECIND/00430/2017), and the doctoral grant (JL, SFRH/BD/136804/2018).