Poly(vinyl alcohol)/tannic acid nanofibrous membrane containing curcumin as an intelligent indicator of food spoilage

In recent years, active packaging technology for extending food shelf life and intelligent packaging technology for monitoring food freshness have become essential for ensuring food safety. Among sensing technologies, pH-sensitive sensors have notable advantages, including simplicity, compactness, and affordability, making them ideal for monitoring food freshness. This study proposes an intelligent food indicator based on a composite nanofiber membrane fabricated by electrospinning. The membrane, composed of poly(vinyl alcohol) (PVA), tannic acid (TA), and the natural pH-sensitive dye curcumin (CUR), was heat-treated to enhance its moisture stability for food packaging. Furthermore, the incorporation of TA and CUR into PVA provides additional benefits such as UV-blocking, antioxidant, and antimicrobial properties, effectively delaying food spoilage. The CUR-incorporated nanofibrous membrane exhibited faster detection of shrimp spoilage via colorimetric changes under increasingly alkaline conditions than film samples. Moreover, compared to film-based samples, the composite nanofiber membrane exhibited faster color change responsiveness owing to its porous and high surface area structure, thus serving as an efficient and intelligent indicator.