Poly-L-lactic acid/lead(II) acetate basic colour indicator membrane for visual monitoring in shrimp freshness

Seafood products are prone to deterioration and, therefore, require a label that identifies quality with the naked eye. A visual freshness colour indicator membrane incorporated with poly-L-lactic acid and lead(II) acetate basic is designed via electrospinning technology for freshness monitoring. The colour indicator membrane had a uniform fibre thickness with an average diameter of 1.54 mu m and a large specific surface area. In addition, the colour stability of the membrane did not vary with temperature and humidity. The hydrogen sulfide (H2S) responsivity results showed that the membrane gave a rapid and accurate response to the freshness of shrimp, and the detection limit of H2S is 0.45 ppm. Finally, in application, the colour change of the membrane correlated linearly with the freshness of the shrimp, allowing the quality of the shrimp to be identified with the naked eye. The experimental results showed that poly-L-lactic acid/lead(II) acetate basic colour indicator membrane had great potential in the detection of shrimp freshness.