Corn waste cellulose as reinforcement component in starch films

Cellulose provides stability and structural resistance to the cell wall of natural fibers. Due to its attributes, it is considered a material with different uses, being applied in composites used for food packaging. Due to the rise of urban solid waste generation and its impacts on the environment, the development of biodegradable and renewable packaging for food applications may be a good alternative. The objective was studying corn waste (corn husk, corn plant and corn cobs) cellulose isolation and its use as reinforcement component on starch films. Cellulose fibers were isolated by alkaline treatment and its morphological, crystallinity properties, and chemical structure by FTIR-ATR were analyzed. The composite films were made by casting with cornstarch and addition of 5, 10, 15 and 20g 100g-1 of husk, plant and corncob cellulose fibers. These composites were evaluated for morphological, thickness, water-solubility, water vapor permeability (WVP), FTIR-ATR, and mechanical properties, and sorption isotherms. The corn waste cellulose after isolation ranged from72.23-74.23%, and the crystallinity was 67.6% (husk), 55% (plant) and 50.7% (corncob). The husk fiber composites presented lower solubility than to the other composites and did not differ by the control yet, presented higher PVA than the control until the concentration of 15g 100g-1. The composites with plant and corncob fibers had higher water solubility and lower PVA than to the control films. Tensile strength and Young modulus oscillated with the addition of husk fibers, while for plant and corncob the tensile strength decreased, and Young modulus initially increased and reduced from the concentration of 10g 100g-1. The composites, regardless of fiber concentration and source, had lower elongation than the control. Moisture in the monolayer reduced with fiber incorporation, except for 5g 100g-1 of husk cellulose. Thus, the composite properties vary according to the intrinsic characteristics of the added fibers and their concentrations.