A poly(vinyl alcohol)/tannin/anthocyanin composite film for food spoilage monitoring

초록

In this study, a poly(vinyl alcohol) (PVA)/tannin (TA)/glycerol/anthocyanin (PTGA) composite film containing the pH-sensitive dye anthocyanin was developed to monitor the freshness and spoilage of food. Heat treatment enhanced the water resistance of PTGA, while the addition of TA bestowed superior transparency above 70 % with excellent UV protection ability. In addition, our study demonstrates that the antioxidant and antibacterial properties of composite film with TA were enhanced compared to films made with pure PVA. Notably, the PTGA film exhibited various color changes depending on the pH and exposure time to ammonia vapor, due to the addition of anthocyanin. The pH sensitivity of the composite film was exploited to monitor the spoilage of chicken breast stored at room temperature for 48 h. To this end, chicken breast freshness indicators (total volatile basic nitrogen and pH) and corresponding LAB color change parameter values (a* (the range from red to yellow), b* (the range from yellow to blue), and color difference (Delta E)) of the composite film were measured. Specifically, a noticeable change in the Delta E value of the film to 15.93 was observed as the chicken breast spoiled, and the b* value also increased from an initial 5.45 to a final 7.07. This confirms that the PTGA composite film is a promising intelligent packaging material for monitoring food spoilage.

키워드