A dual antioxidant and antimicrobial bioplastic film endowed with amine-branched poly(lactic acid): Bioactive packaging for electron beam sterilization and food shelf-life extension.

Cyclic amine-multibranched poly(lactic acid) (mPLA) was prepared as a dual antioxidant and antimicrobial toward PLA active packaging for food shelf-life extension in a case study of bread. The mPLA was coupled with piperidine (PPR) containing a heterocyclic amine derivative, which is a nature-rich bioactive function. The functions of mPLA-PPR enhancing the PLA film performance were studied in comparison with PPR, mPLA and Tinuvin® 770. The mPLA-PPR promoted miscible nucleating action in the PLA film, and the elongation at break and ductility of PLA/mPLA-PPR were significantly improved with a resistivity against electron beam (EB) irradiation. The mPLA-PPR in the PLA film showed its antioxidation potential in both solution media and solid state. The PLA free radicals in solid-state created upon EB irradiation were efficiently stabilized by mPLA-PPR. The migration of PPR from the PLA matrix into food simulants was retarded when it was anchored on the mPLA. The PLA active film has antibacterial activity to inhibit the growth of E. coli and antimicrobial activity to inhibit expansion of natural molds on bread slices. This current study showed that the PLA/mPLA-PPR active film is a promising model of a functional bioplastic packaging for EB processed food sterilization and for food shelf-life extension.