Modified poly lactic acid film for food packaging

Abstract

The focus of this thesis is on poly-(lactic acid) (PLA)-based food packaging films newlinemodified with natural plasticizers, antioxidants, and antimicrobials. PLA is one of the newlinemost commonly used biopolymers in packaging. However, the applicability of this newlinepolymer in food packaging industry is limited due to its brittle nature. newline The thesis is divided into seven chapters. The first chapter provides an overview of newlinefood packaging, active packaging, green packaging, and antioxidants. This chapter also newlineconsists of critical literature review, the scope, and objectives of the thesis. A detailed newlinediscussion of the various materials and experimental techniques used for the work is newlinegiven in Chapter 2. newline The plasticizing effect of mango seed wax (MSW) on PLA films was discussed in newlineChapter 3. The hydrophobicity and barrier properties of the PLA films has been increased newlinein presence of MSW. The plasticized film is appeared transparent, just like pristine PLA. newlineEven though MSW showed a migration toward fatty foods, it is not toxic to human health newlineor to the environment. It is considered as a substitute for cocoa butter and used as a newlinechocolate ingredient. The presence of MSW helped PLA to increase the induction time newlineat high processing temperatures. newline Chapter 4, describes the functionalisation of PLA using carnosic acid for the newlinedevelopment of active packaging film. Carnosic acid is a powerful natural antioxidant newlinefound in the leaves of the rosemary herb. The presence of MSW enabled the uniform newlinedistribution of CA in the PLA matrix. The thermal stability of the active film has been newlinefound reduced from that of pristine PLA. But it is still greater than the processing newlinetemperature. newline