Aiming at the sustainable use of biodiversity in the Brazilian Cerrado, the wolf fruit has high potential as a new plant source for the development of ecologically correct packaging. In view of the full use of wolf fruit, cellulose nanofibers (NCs) were obtained from the peels by acid hydrolysis, using different concentrations of sulfuric acid (0.1%, 1% and 10% v/v). Starch was extracted from the fruit pulp and incorporated biodegradable films of NCs (5% w/w) as reinforcing agent were produced by the casting method. The effects of the addition of NCs on the properties of the resulting nanocomposites were investigated. The presence of nanoparticles improved the thermal stability of the films, due to the strong intermolecular interactions that occur between starch and cellulose. The produced nanocomposites exhibited a significant increase in tensile strength, Young's modulus and opacity with the addition of NCs. Cellulose nanofibers isolated at a sulfuric acid concentration of 0.1% (NC 0.1) have the potential to be used as reinforcing agents in biopolymer-based films, since the nanocomposite added of this nanoparticle (F0.1) showed good mechanical resistance (stress at break = 7.45 MPa and Young's modulus = 471.57 MPa) compared to the control film (FC) (stress at break = 5.19 MPa and Young's modulus = 274.38 MPa). In addition, obtaining this nanoparticle (NC 0.1) occurs under the mildest conditions of chemical treatment, being economically viable (from an energy point of view) and presenting environmental advantages. The small differences observed in the properties of nanocomposites in relation to chemical treatment do not justify the use of more drastic processes. This work presented a possible use of a by-product from wolf fruit processing as an innovative product for future applications in the food industry.