RESUMO
This study aimed to evaluate the feasibility of the production of sustainable and biodegradable packages made from a little-explored by product of wheat-milling, the glue flour (GF). Films were produced by the casting method and the effect of the incorporation of glycerol, sorbitol, and GF in the properties of the films was investigated following the central composite rotational design (CCRD) approach. The results have been statistically analyzed by the response surface methodology and the desirability function. Due to the rich composition in amylaceous reserve (64.81%; 26% of amylose content), considerable protein content (11.23%), and fibers (8.28%), the GF proved to be suitable for use as a matrix in biopolymer films. All the properties were mainly influenced by the plasticizer type and GF concentration. Film plasticized with glycerol (run 13) was more flexible, had higher moisture (28.39%) content, and was more adhesive than the formulation made with sorbitol (run 11). Film elongation (ELO) ranged from 25.84% to 56.71%, and tensile strength (TS) from 0.10 to 2.8 MPa. The optimized process conditions were 8% for Cf, 0% for Cg, and 4% for Cs. Under these conditions, the films presented low moisture (12.1%), moderate solubility (35.5%) and TS (1.64 MPa), and high ELO (72.06%). This study showed that GF is a promising source for the development of biodegradable films. PRACTICAL APPLICATION: Films made from a by product of wheat flour (glue flour) have technological potential to be used as packaging for food products. The valorization of a by product of the agribusiness without pre-treatment for the production of biodegradable films was made possible. The study by casting technique is a previous for scale-up production.
