Cellulose laurate films containing curcumin as photoinduced antibacterial agent for meat preservation

Hydrophobic cellulose laurate (CL) with high degree of substitution has been successfully synthesized. The mechanical property, water-resistance, antimicrobial activity, barrier properties and food decontamination of cellulose-laurate-curcumin films (CL-Cu_x, x = 0.1, 0.5, and 1) were investigated. The results showed that the mechanical properties of CL-Cu_x hardly change after soaking in water for 24 h, probably due to the strong hydrophobicity of cellulose laurate. CL-Cu₁ represented a good photoinduced antibacterial effect against S. aureus. After irradiation of white light at 60 mW·cm^-2 for 20 min, the inhibition efficiency reached to 95 ± 2.02%, probably owing to the generated active ¹O₂. In comparison with CL-Cu₁ stored in natural light, the bacteriostatic effect of CL-Cu₁ in dark storage was better, and the inhibition rate of CL-Cu₁ remained 80 ± 1.22 at 60th day. The stabler excited state of curcumin in hydrophobic cellulose laurate was probably assigned to inhibition of tautomerism or conformational transition, which was beneficial to the generation of singlet oxygen. CL-Cu₁ can significantly inhibit the growth of TVBN and TVC values of chilled meat upon white light irradiation, indicating the potential application of cellulose-laurate-curcumin films in food decontamination.