Preparation of sodium alginate/pectin/cellulose nanofibrils films containing black soybean seed coat anthocyanins for monitoring goat meat freshness

Rising consumption of goat meat in recent years is challenged by its susceptibility to microbial contamination during post-slaughter storage, necessitating innovative and smart packaging. Here, a pH-responsive film was developed using a sodium alginate (SA)/pectin/cellulose nanofiber (CNF) film matrix with different concentrations of black soybean seed coat anthocyanins (BSSCA) (0%, 2.5%, 5%, 7.5%, and 10% w/w) for monitoring goat meat freshness. Using this matrix, multistage utilization of black soybean seed coat (BSSC) was achieved. The FT-IR and XRD results revealed that BSSCA combined well with the substrate by forming intermolecular hydrogen bonds. Scanning electron microscopy exhibited good compatibility between the substrates of the composite film. BSSCA addition significantly increased the thickness and elongation at break; improved the barrier properties (UV and water vapor barrier properties); reduced the moisture content, water solubility, swelling, and tensile strength of the film. Meanwhile, the colorimetric film exhibited excellent pH sensitivity. During room temperature storage of goat meat, the colorimetric films displayed an excellent color response with decreasing quality of goat meat. Considering our cumulative observations, BSPC-7.5 has a promising application and broad market prospects as a packaging film by indicating the freshness of goat meat.