Modeling and Optimization of Bio‐Based Cassava Starch Film Enriched With Coconut Derivatives ( Cocos nucifera L.) and Ocimum gratissimum Essential Oil Based on Its Barrier and Mechanical Properties

The postharvest quality of food products in general, and highly perishable products such as vegetables in particular, is a major concern today. The aim of this study was to develop a cassava starch‐based film formulation incorporating natural substances for use in food preservation using response surface methodology (Box–Behnken design). The independent variables were Ocimum gratissimum essential oil (OEO) concentration, defatted coconut flour (DCF), and virgin coconut oil (VCO) percentage. The first part focused on producing 15 formulations specified in the plan with varied compositions. The second part was to determine optimum film based on its properties. The results showed a significant effect ( p ≤ 0.05) of these variables on all the film characteristics. In addition, OEO (from 0.7 to 0.8 mg/L) and DCF ( Cocos nucifera L.) (from 0% to 10%) influence film tensile strength and thickness, respectively. The essential oil has a quadratic effect on the tensile strength of the films. In addition, the incorporation of VCO significantly (from 0% to 10%) reduces films water vapor permeability (1.605 × 10 −10 to 3.9 × 10 −11 g/s.Pa.m) and the elongation at break (12% to 34%). The optimal formulation of the film preparation contained 0.80 mg/L of OEO, 6% of DCF and 4% of VCO. XRD and FTIR tests revealed that the components in the optimized film formulation interact via hydrogen or ionic bonds and that these interactions modified the structure of the material, changing it from an amorphous network to a crystalline restructuring. These findings provide valuable insights into the complex interplay of film properties and the components used in production. Food coating films can be prepared using this formulation for use in vegetable preservation.