Composition optimization and safety assessment of lactic-acid-bacteria-loaded composite film

In this experiment, response surface methodology-central composite rotatable design was used to optimize the ratio of hydroxypropyl cellulose, konjac flour, and glycerol to obtain optimal composite film. Taking into account the importance of tensile strength, elongation at break and lactobacillus survivability, to the overall properties of composite film, a comprehensive index was proposed to evaluate comprehensive property by fuzzy comprehensive evaluation method. Optimization experiments showed that the optimal composition of the biocomposite membrane that maximized the combined response value was 0.586% HPC, 0.858% KF, and 1.620% GL. In vitro toxicology experiments were used for the safety evaluation of the membranes. In the 14-day feeding test, the mice in each experimental group grew well, and there were no obvious abnormalities in gross anatomical organs and related blood biochemical indicators. A 14-day mouse feeding experiment showed that the biocomposite film had no short-term toxicity, so the biocomposite film could be considered food-safe.