Mechanical properties optimization of edible clove oil/chitosan composite materials by multi-island genetic algorithm for active fresh-keeping packaging applications

The non-degradability of petroleum-based fresh-keeping film materials has led to a series of environmental pollution problems, especially in the field of fruits and vegetables packaging. In this work, an edible composite packaging material with sustained-release property was prepared by optimizing the ratio of using chitosan (CS), glycerol (Gly), and clove essential oil (Clove oil) with the methods of response surface and multi-island genetic algorithm (MIGA). The physical and fresh-keeping properties of the material were thoroughly investigated and analyzed. As a result, 0.42 % Gly, 0.4 % Clove oil , and 1.5 % CS of optimal iteration results were obtained to prepare edible composite packaging material , which has good antimicrobial properties and fresh-keeping performance, and can keep the strawberry with good taste, appearance, and nutrition after 5 days of storage. The tensile strength and elongation at break of the Clove oil/CS composite material respectively reached 18.55 MPa and 14.3 % under the condition of optimal iteration. Besides, the Clove oil/CS composite solution coating method (SCM) was better than the Clove oil/CS composite film wrapping method (FWM) in the fresh-keeping effect of strawberries, increasing their shelf life to 5 days, which is because the barrier and antimicrobial properties of SCM are better than those of FWM. The obtained mathematical model of the tensile strength and elongation at break provided a theoretical basis for preparing different fresh-keeping performances of the CS composite material. This work provided valuable application and theoretical references for the preservation of fruits and vegetables.