SMART AND ECO-FRIENDLY FILMS: HARNESSING JABUTICABA PEEL FLOUR'S POTENTIAL

The jabuticaba (Plinia jaboticaba), a Brazilian fruit, is renowned for its richness in nutrients and anthocyanins, antioxidant pigments. The remarkable ability of anthocyanins to change color according to pH makes them suitable for smart films. By extracting these anthocyanins from frequently discarded peels, we align with the circular economy and sustainable packaging principles. In this context, the present study aimed to develop smart biodegradable films by using jabuticaba peel flour (JF). The casting technique was employed to produce films with different JF concentrations (0%, 1%, and 10%), while cassava starch was used as the matrix. Films evaluation included water solubility, pH-responsive color change, optical and mechanical properties. The 1% JF film exhibited a 13% reduction in water solubility compared to the control film, potentially attributed to the formation of a fiber network hindering water diffusion. On the other hand, adding 10% JF increased water solubility by 22%, possibly due to an excess of fibers, which could act as crack initiators and weaken the fiber network within the material. Compared to the control film, the 1% JF film exhibited increased tensile strength and Young's modulus but reduced elongation at break due to strong fiber-starch matrix interactions limiting chain motion. However, the 10% JF film was less mechanically resistant, primarily due to the higher fiber content weakening the film structure. The control film presented transparency, whereas the incorporation of JF induced darkening, resulting in a purple/red hue attributed to the presence of anthocyanins. Incorporating JF produced films sensitive to extreme pH variations (pH 1 and 11), with the 1% JF film showing a more pronounced color change. In summary, JF films exhibited favorable properties, including pH-responsive color changes, suggesting their potential as effective pH indicator films for monitoring food freshness during storage and assessing food shelf life.