An Intelligent Label for Freshness of Fish Based on a Porous Anodic Aluminum Membrane and Bromocresol Green

A sensitive and intuitive freshness intelligent label was fabricated for indicating the freshness of fish based on porous anodic aluminum (PAA) membrane and bromocresol green. This label is fabricated by the bromocresol green (BCG) immobilized on PAA membrane, which responds through visible color change to the total volatile basic nitrogen (TVBN) released during fish spoilage period. The result showed that the fish is inedible when it was stored at 25 degrees C for 6 h (TVBN > 20 mg/100 g). Under this condition, the color of BCG/PAA label changed from yellow to green obviously. In addition, BCG/PAA membrane label and the electrospinning nanofiber label were used to evaluate the fish freshness. As a result, the color of BCG/PAA membrane label is more obvious and sensitive. Thus, BCG/PAA membrane label can be considered as a new promising method for the assessment of fish freshness.