Eco-friendly bean flour films for sustainable food packaging

Abstract

The use of natural polymers in packaging development is a promising alternative to solve the environmental problems associated with petroleum-based synthetic packaging. This study proposed the production and use of black and red bean flours as a non-conventional biopolymer matrix for the development of biodegradable films. Films with 10 and 25 g of film-forming solution of black bean and red bean flour (separately) were produced by the casting technique and characterized in terms of physical-chemical, barrier and structural properties. The film with 25 g of red bean flour film-forming solution showed a tensile strength of 9.5 MPa and a water solubility of 32.9%, higher values than the other films produced. Regarding the water vapor permeability, the formulation with 10 g of film-forming solution of red bean showed the lowest value (1.3 g.mm/h.m2.kPa) when compared to the value of 2.3 g.mm/h.m2.kPa for the formulation with 25 g of film-forming solution of red bean. The films presented similar relative crystallinity and a predominantly homogeneous surface. All films presented total biodegradability in 14 days in soil, and 20 days in sea water. The red bean flour films presented better mechanical and barrier properties, and also were able to be sealed and printed. It is believed that this packaging could be used to package products such as olive oil, because in addition to containing the product, its low transparency could prevent oxidative processes caused by the light incidence.