Practical Guide to Antimicrobial Active Packaging

278 Pages·2015·2.277 MB·English

by  Gavara, Rafael

Practical Guide to Antimicrobial
Active Packaging
Rafael Gavara
Practical Guide to
Antimicrobial Active
Packaging
Rafael Gavara, Gracia López-Carballo,
Pilar Hernández-Muñoz, Ramón Catalá
Virginia Muriel-Galet,
Josep P. Cerisuelo and Irene Domínguez
A Smithers Group Company
Shawbury, Shrewsbury, Shropshire, SY4 4NR, United Kingdom
Telephone: [phone] Fax: [phone]
http://www.polymer-books.com
First Published in 2015 by
Smithers Pira Technology Ltd
Shawbury, Shrewsbury, Shropshire, SY4 4NR, UK
©Smithers Information Ltd., 2015
All rights reserved. Except as permitted under current legislation no part
of this publication may be photocopied, reproduced or distributed in any
form or by any means or stored in a database or retrieval system, without
the prior permission from the copyright holder.
A catalogue record for this book is available from the British Library.
Every effort has been made to contact copyright holders of any material reproduced
within the text and the authors and publishers apologise if
any have been overlooked.
ISBN: 978-1-91024-273-5 (hardback)
978-1-91024-209-4 (softback)
978-1-910-24210-0 (ebook)
Typeset by Integra Software Services Pvt. Ltd.
Printed and bound by Lightning Source Inc.
P
reface
Active packaging technologies are being developed to control the various problems
associated with food deterioration or spoilage, such as the control of oxygen,
carbon dioxide, ethylene or humidity inside the packaging, addition of chemical
preservatives, elimination of off-odours and undesirable substances, and the control
of microbiological contamination. Among these technologies, antimicrobial active
packaging systems, defined as those that beneficially interact with food or the
surrounding environment to inhibit or reduce microbial growth, have undoubtedly
become a fully accepted alternative to the direct addition of preservatives to foods
and have excellent future prospects for improving the quality and extending the
shelf life of industrially produced foods. Accordingly, active packaging has become
one of the so-called emerging non-thermal food technologies, which are being
implemented to provide the consumer with natural, fresh, quality food without
compromising safety.
The aim of this book is to develop a working knowledge and understanding of
antimicrobial packaging. After a brief introduction on the antecedents and basics
of active packaging, the various issues to be considered in order to manufacture
successful, efficient active antimicrobial packaging are covered. In Chapters 1–5,
the antimicrobial agents most commonly used and their mechanisms of action are
described, the manufacturing methods available to manufacture the active system are
detailed, the parameters that are critical to make an effective product are discussed
and tools to optimise them are provided, in addition the various in vitro and in vivo
methods for measuring the effectiveness of the antimicrobial system are described
in detail. Chapter 6 provides a collection of references detailing the most interesting
developments and commercially available antimicrobial packaging systems. Finally,
Chapter 7 presents a case study, from conception to manufacture, validation and
optimisation.
This book also aims to develop an understanding of why a specific agent is selected
for a particular food product, or why a specific polymeric material and manufacturing
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Practical Guide to Antimicrobial Active Packaging
technology are chosen. The reader will become familiar with the different procedures
for improving the activity of the developed packaging solution and ways of testing its
efficacy. This will accelerate the formulation of the active packaging concept, reducing
development time with respect to the trial-and-error processes common in many of
the reports for which references are given. Finally, it will help to identify the best and
most cost-effective solutions.
iv
A
cknowledgements
The authors acknowledge the financial support of the Spanish Ministry of
Economy and Competitiveness for Project AGL2012-39920-C03-01. Irene
Domínguez thanks the CSIC for the provision of a postdoctoral contract (JAE-
DOC), which was cofunded by ESF. The authors are also grateful to Karel
Clapshaw for language services.
v

C
ontents
Preface ..........................................................................................................iii
Acknowledgements .........................................................................................v
Contents .......................................................................................................vii
About the Authors – Affiliation ....................................................................xi
1 Introduction to Active Packaging ..................................................................1
1.1 Packaging and Active Packaging ..........................................................1
1.2 Plastic Materials for Packaging ............................................................3
1.2.1 General Characteristics of Plastics ...........................................3
1.2.2 Important Properties of Plastics for Packaging ........................5
1.2.2.1 Mechanical Properties .............................................5
1.2.2.2 Optical Properties ...................................................5
1.2.2.3 Thermal Properties ..................................................5
1.2.2.4 Mass Transfer Properties .........................................6
1.2.3 Principal Plastics used for Packaging .......................................7
1.2.3.1 Polyolefins ...............................................................7
1.2.3.2 Polystyrenes ............................................................9
1.2.3.3 Vinyl Polymers ......................................................10
1.2.3.4 Polyesters ..............................................................11
1.2.3.5 Polyamides ...........................................................12
1.2.3.6 High-barrier Polymers ...........................................12
1.2.3.7 Bioplastics .............................................................13
1.2.4 Packaging Production Technologies ......................................13
1.2.4.1 Flexible Packaging .................................................13
1.2.4.2 Rigid Packaging ....................................................14
1.2.5 Food/Plastic Packaging/Environment Interactions .................15
1.2.5.1 Permeability ..........................................................16
1.2.5.2 Sorption ...............................................................17
1.2.5.3 Migration .............................................................17
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Practical Guide to Antimicrobial Active Packaging
1.3 Active Packaging: Basic Characteristics .............................................18
1.3.1 Antimicrobial Active Packaging ............................................21
References ...................................................................................................22
2 Antimicrobial Agents ...................................................................................25
2.1 Minimum Inhibitory Concentration and Minimum
Lethal Concentration .........................................................................25
2.2 Antimicrobial Agents used in Active Packaging .................................27
2.2.1 Enzymes ................................................................................28
2.2.1.1 Bacteriolytic Enzymes ............................................28
2.2.1.2 Antimicrobial Oxidoreductase Systems .................29
2.2.2 Bacteriocins ...........................................................................30
2.2.3 Bacteriophages ......................................................................33
2.2.4 Surfactants ............................................................................34
2.2.5 Plant Extracts ........................................................................36
2.2.6 Polysaccharides .....................................................................39
2.2.7 Organic Acids .......................................................................40
2.2.8 Metals ...................................................................................41
2.3 Factors which affect the Properties and Stability of Antimicrobial
Agents during the Processing of Packaging Films ...............................43
References ...................................................................................................45
3 Active Packaging Systems ............................................................................53
3.1 Active Component Preparation ..........................................................53
3.1.1 Use of an Inorganic Substrate ................................................54
3.1.1.1 Clay Nanocomposites ...........................................56
3.1.1.2 Metal Nanoparticles ..............................................58
3.1.1.3 Mesoporous Silica .................................................60
3.1.2 Encapsulation in an Organic Substrate ..................................61
3.1.2.1 Criteria for Antimicrobial
Agent Encapsulation .............................................62
3.1.2.2 Matrices for Encapsulation ...................................63
3.1.2.3 Encapsulation Methods .........................................65
3.2 Independent Devices ..........................................................................69
3.3 Incorporation into Packaging Structures ............................................72
3.3.1 Incorporation into Packaging Structures by
Thermomechanical Methods .................................................72
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Contents
3.3.1.1 Preparation of Active Materials by
Compounding .......................................................74
3.3.1.2 Preparation of Active Materials by
Extrusion ..............................................................75
3.3.1.3 Extrusion Coating .................................................77
3.3.2 Wet coating ...........................................................................78
3.3.2.1 Coating .................................................................79
3.3.2.2 Spraying ................................................................84
3.3.3 Surface Anchorage ................................................................85
3.3.3.1 Sample Preparation ...............................................86
3.3.3.2 Surface Modification .............................................87
3.3.3.3 Attachment of Biomolecules
to the Surface ........................................................88
3.3.3.4 Surface Analysis and Determination
of Film Activity .....................................................90
References ...................................................................................................90
4 Modelling and Optimisation of Active Packaging:
Parameters Related to Antimicrobial Efficiency ...........................................97
4.1 Mass Transport..................................................................................98
4.2 Determination of Mass Transport Parameters ..................................105
4.3 Release Control ...............................................................................110
4.4 Modelling Release of the Agent .......................................................115
4.4.1 Modelling and Description using the
Finite Difference Method ....................................................117
4.4.2 Modelling and Description using the
Finite Element Method ........................................................120
References .................................................................................................122
5 Methods for the Analysis of Antimicrobial Packaging Efficiency ...............125
5.1 In Vitro Methods .............................................................................127
5.1.1 Disc Diffusion Method ........................................................128
5.1.2 Dilution Method .................................................................131
5.1.3 Japanese Industrial Standard Method .................................137
5.1.4 Surface Growth Method .....................................................139
5.1.5 Electron Microscopy ...........................................................140
5.1.6 Atomic Force Microscopy ...................................................142
5.1.7 Flow Cytometry ..................................................................144
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