non-toxicity, low-density, biocompatibility properties, and low cost. [1][2][3][4][5] The main drawback associated with the use of cellulose in specific composites-related applications is its water sensitivity and ability to uptake significant amounts of moisture. [6][7][8] On the other hand, cellulose fibers have very good mechanical properties, and because of this, they have been employed to reinforce many petroleum polyolefins or bio-based resins. [9][10][11] Advances in the development of cellulose nanofibers and bacterial cellulose have led to many new generation cellulose composites with superior mechanical properties and functionality. [12][13][14][15][16] In addition, many different physicochemical methods have also been developed to extract cellulose from agricultural and food wastes including biomass that can potentially reduce deforestation related to cellulose production feedstock. [17][18][19][20] Many sustainable packaging solutions and technologies must guarantee product safety and increase shelf life while decreasing pollution related to nondegrading plastics. It is believed that biobased responsive polymers and composites can address this necessity if accompanying economic and environmental benefits are also demonstrated. This study is motivated by these recent advances. At the same time, recent awareness in reducing environmental plastic pollution has fueled a significant momentum towards using natural polymers Development of responsive bio-based and biodegradable materials is particularly important in food preservation and monitoring technologies. Although replacing conventional plastic products with sustainable alternatives is still a challenge, promising advances have been reported. In this work, the fabrication of responsive bio-composite films from polycaprolactone (PCL) and magnesium carbonate (MgCO 3 ), known as food additive E504 with melt impregnation into cellulose, is reported. Cellulose fibers are stained/coated with ethanoic curcumin solutions, primarily to protect them against oxidative degradation. The films demonstrate a strong antioxidant effect against fatty and aqueous food simulants with improved oxygen gas barrier properties. Interestingly, the natural chelation of curcumin with magnesium within the composites improves the bioavailability and antioxidant potency of curcumin. Moreover, the composites show reversible color change response detectable by the naked eye in basic solutions or vapors. This response is tested by placing the composite film inside a sealed plastic container containing shrimp at room temperature, but not in direct contact. Due to spoilage, a noticeable color change in the bio-composites is recorded. These simple, cost-effective, non-toxic, and paper-like flexible bio-composites can be fabricated on large scale and be used in diverse applications ranging from sustainable packaging to medical applications and freshness indicators.