ABSTRACT
Increased and indiscriminate use of plastic packaging lms, which are petroleum based, has led to ecological problems due to their total nonbiodegradability. Continuous use of plastics in any form or shape has to be restricted and may even be gradually abandoned to protect and conserve environment. Such awareness, of late by one and all, has led to a paradigm shift to look for packaging lms and processes that are biodegradable and, therefore,
CONTENTS
7.1 Introduction ................................................................................................ 169 7.2 Experimental .............................................................................................. 175
7.2.1 Materials .......................................................................................... 175 7.2.2 Preparation Procedures................................................................. 175
7.2.2.1 Hydrogel Preparation and Purication ....................... 175 7.2.2.2 Polyolen Film Processing ............................................. 180
7.2.3 Investigation Methods................................................................... 180 7.2.3.1 Aroma Loading and In Vitro Release Studies ............ 180 7.2.3.2 Mechanical Properties .................................................... 181 7.2.3.3 Oxidation Induction Period ........................................... 181 7.2.3.4 Antimicrobial Activity ................................................... 182
7.3 Results ......................................................................................................... 182 7.3.1 Vanillin Release from Chitosan Nanocomposite Hydrogels ... 182 7.3.2 Vanillin Release from Xanthan/Lignin Hydrogels .................. 184 7.3.3 Polyolen/Lignin Composites ..................................................... 186
7.4 Conclusion .................................................................................................. 190 Acknowledgments .............................................................................................. 191 References ............................................................................................................. 191
compatible with the environment. Such an approach also leads to natural resource conservation with an underpinning on a pollution-free environment. Thus, the concept of biodegradability enjoys both user-friendly and eco-friendly attributes, and the raw materials are essentially derived from either replenishable agricultural feed stocks (cellulose, starch, and proteins) or marine food processing industry wastes (chitin/chitosan). Their total biodegradation to environmentally friendly benign products (CO2, H2O/quality compost) is the turning point that needs to be capitalized upon. Polymer cross-linking and graft copolymerization of natural polymers with synthetic monomers are other alternative approaches of value to using biodegradable packaging lms. Although complete replacement of synthetic plastics may be impossible to achieve and perhaps even unnecessary, at least for a few specic applications, attention and efforts are required in the days to come. Though expensive, biopackaging meets tomorrow’s need for packaging, especially for a few value-added products. It offers an attractive route to waste management, as well.1 Most materials currently used for food packaging are nondegradable, generating environmental problems. Several biopolymers have been exploited to develop materials for eco-friendly food packaging. However, the use of biopolymers has been limited because of their usually poor mechanical and barrier properties, which may be improved by adding reinforcing compounds (llers), forming composites. Most reinforced materials present poor matrix-ller interactions, which tend to improve with decreasing ller dimensions. The use of llers with at least one nanoscale dimension (nanoparticles) produces nanocomposites. Nanoparticles have proportionally larger surface area than their microscale counterparts, which favors the ller-matrix interactions and the performance of the resulting material. Besides nanoreinforcements, nanoparticles can have other functions when added to a polymer, such as antimicrobial activity, enzyme immobilization, biosensors, etc.2
