Starch/PBAT Composite Films With Hybrid Silicates: Structure–Property Relationships and Application in Cherry Modified‐Atmosphere Packaging

Abstract

Starch/poly(butylene adipate‐co‐terephthalate) (PBAT) composite films containing dual silicate fillers were fabricated by extrusion blowing for biodegradable modified‐atmosphere packaging (MAP). The combination of diatomite, kaolin and zeolite was associated with a filler‐mediated interfacial network that enhanced mechanical strength, flexibility and transparency while regulating gas‐transport pathways. A steady‐state analysis suggested that the internal CO 2 /O 2 equilibrium depends on the coupling between fruit respiration and film gas selectivity. Among all formulations, the diatomite–zeolite film (D‐Z) exhibited balanced O 2 /CO 2 permeability, low humidity sensitivity and superior structural uniformity, enabling the formation of a stable atmosphere with low O 2 (1.1%) and moderate CO 2 (14.3%) levels. When applied to cherry preservation, the D‐Z film effectively delayed spoilage and maintained fruit quality. This work provides a feasible strategy for designing sustainable, humidity‐tolerant and atmosphere‐regulating bioplastic films for fresh produce packaging.