A Bioactive Chitosan&minus;Based Film Enriched with Benzyl Isothiocyanate/&alpha;&minus;Cyclodextrin Inclusion Complex and Its Application for Beef Preservation
A bioactive packaging material based on chitosan (CS) incorporated with benzyl isothiocyanate (BITC) and &alpha;&minus;cyclodextrin (&alpha;&minus;CD) was fabricated to evaluate its preservative effects on fresh beef stored at 4 &deg;C for 12 d according to the quality analysis. The Fourier-transform infrared (FTIR) spectrum revealed that the major structural moiety of BITC was embedded in the cavity of &alpha;&minus;CD, except for the thiocyanate group. FTIR and X&minus;ray diffraction analysis further verified that intermolecular interactions were formed between the BITC&minus;&alpha;&minus;CD and CS film matrix. The addition of BITC&minus;&alpha;&minus;CD decreased the UV light transmittance of pure CS film to lower than 63% but still had enough transparency for observing packaged items. The CS&minus;based composite film displayed a sustainable antibacterial capacity and an enhanced antioxidant activity. Moreover, the total viable counts, total volatile base nitrogen, pH, thiobarbituric acid&ndash;reactive substances, and sensory evaluation of the raw beef treated with the CS&minus;based composite film were 6.31 log colony-forming unit (CFU)/g, 19.60 mg/100 g, 6.84, 0.26 mg/kg, and 6.5 at 12 days, respectively, indicating the favorable protective efficacy on beef. These results suggested that the fabricated CS&minus;based composite film has the application potential to be developed as a bioactive food packaging material, especially for beef preservation.