Real-time shrimp freshness detection by anthocyanin-enriched wheat gluten/gelatin electrospun nanofiber films

Electrospun nanofiber films exhibited significant potential as food freshness indicators (FFI) due to their structural advantages. Herein, a novel electrospinning film based on wheat gluten (WG), gelatin, and anthocyanins was fabricated to detect the freshness of shrimp. Compared with pure WG, an adjusted ratio of the WG to gelatin (W16E9, 16:9) improved physicochemical properties, reducing viscosity from 3.56 to 2.75 Pa.s and increasing conductivity from 1.53 to 2.06 mS/cm. SEM showed a transition from bead-like to fibrous morphology (691.6 nm diameter). The films exhibited improved thermal properties, and increased water solubility from 38 % to 45 %. The anthocyanin-enriched film (W16E9A2) maintained a stable purple-red color at −18, 4 and 25 °C for 14 days. It showed sensitivity to acetic acid and ammonia within 40 s, correlating with TVB-N and TVC in shrimp (R² = 0.988 and 0.962), distinguishing freshness within 36 h. This work provided a viable protein-based anthocyanin nanofiber film as FFI.