Sustainable Polymers for Food Packaging

An Introduction

Vimal Katiyar

• Publisher: De Gruyter
• Year: 2020
• ISBN:
  9783110644630
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Industrial & Technical Chemistry

Bio-based plastics and nanocomposites can be used in improved packaging for food. The morphologies and physical and chemical properties of food packaging must be carefully controlled. This book covers topics such as: food packaging types, natural polymers, material properties, regulations and legislation, edible and sustainable food packaging, and trends in end-of-life options. This book is ideal for industrial chemists and materials scientists.

1 Sustainable polymers for food packaging: an introduction

Kiran Kumar Gali

Purabi Bhagabati

Vimal Katiyar

The world’s population is increasing day by day. As per the UN report, it is 7.3 billion at present and is set to grow to around 10.9 billion by 2050, where in it will become very difficult to feed the required nutrients to humans at least three times a day [1]. Therefore, storage of food with proper safety and its continuous and economical supply in adequate quantities to each person is the crucial factor where food-packaging technology plays a vital role. The ultimate purpose of packaging is to protect the food from surroundings by maintaining the quality and shelf life of the food product. The food packaging industry addresses the demands of the commercial, legal and communication barriers along with convenience tamper indication and traceability as the secondary barriers, by adopting cost-effective methods. Effective packaging materials and suitable packaging processes are the most important factors toward ensuring the quality and freshness of food at different stages of storage and distribution.

Packaging negates the chances of contamination of food items and also minimizes the wastage of foodstuff. Packaging of food items is the most important criterion, which protects it from various physical damage during transportation, preserves it from various unwanted chemical and atmospheric environment and extends the shelf life of packaged food items. Without effective packaging, it will be difficult for modern food industries to distribute bulk amount of raw and processed foods to distant areas of their marketing with a motive to supply the required nutrients uniformly to each stakeholder of the society, without any spoilage of food. In the subsequent sections, a detailed discussion will be made on different types of packaging with respect to food items and different packaging materials. Furthermore, the discussion will be extended to various plastic materials such as petroleum and biobased, differentiating biobased (in relation to their origin) and biodegradable (in relation to their end) plastics and their positive impact on the environment.

1.1 Types of food packaging

Packaged food products are mainly available in polymeric flexible film-based bags, wrappers, boxes, trays, caps, bottles, edible packaging materials and so on. Packaging helps in protecting the form, shape and texture of some delicate food items, in addition to preventing the loss of flavors or aroma. It is a mandate that the packaging material must not affect the nutritional value and quality of a packaged food product. Along with the storage capacity, packaging in proper form is necessary to carry out safe transportation across longer distance in large quantity.

The basic functions of packaging are to:

1. contain the packaged material,
2. preserve the packaged material from outside harmful environment,
3. transport the packaged material safely from the production warehouse to the consumers,
4. provide accurate information about the packaged material to the consumers.

Based on these primary functions, packaging can be classified into three simple categories. For better understanding of the readers, Figure 1.1 illustrates the types of packaging used in the food sector in terms of its demand in the market.

Figure 1.1: Types of food packaging in terms of its quantitative demand.

1.1.1 Primary packaging or sales packaging

This is the packaging that wraps the food items that are in direct contact with the packaging. Hence, this packaging material has much required functionalities in terms of retaining property of food items without causing any problem. Besides the action of preservation of food quality and shelf life, the packaging material should also be non-reactive with the packaged food items. Based on the type of food to be packaged, the packaging materials can be grouped into metals and its alloys, glass, polymeric containers and films and others.

1.1.2 Secondary packaging or group packaging

This is the packaging that consists of a number of primary packages regardless of whether it is sold in bulk or in loose to the consumers. Paperboard cartons and boxes made of biobased biodegradable jute bags are some of the secondary packaging materials. Also, hard and tough plastic containers, trays and boxes fall under this category of packaging.

1.1.3 Tertiary packaging or transport packaging

The functions of tertiary packaging are mainly the transportation of the primary or secondary packaged material to the customers. Another purpose of this packaging is to prevent physical damage due to inappropriate handling or transportation of grouped packages. Large wooden or metallic boxes are the most commonly used tertiary packaging materials to serve the purpose.

However, it is important to understand that different food items require different types of properties in its packaging material. Specifically, such diversity can be observed in case of primary packing materials as foods directly come in contact with the packaging materials. Hence, importance must be given to the primary packaging materials so that it does not affect the chemical, physical and aroma along with the shelf life of the packaged food items. Furthermore, detailed discussion will be made on various food-packaging materials used in the market.

1.2 Materials for food packaging

The food-packaging industry uses glass, paperboards, aluminum, tin, steel and other metals and plastics in various forms for flexible and rigid use [2].

1.2.1 Glass material

Glass is the most common and the oldest ever food-packaging material used in the form of containers, bottles, bowls, trays, cups and so on. In food packaging applications, glass is mostly used in combination with some other materials like metal, cork, plastic, rubber and others as a single unit. The type of glass enclosure depends on the nature of the food items that would be stored. For example, foodstuffs with sensitivity toward outside atmosphere or those that need sterilization by heat, will be enclosed in containers with rubbery gaskets. Foodstuffs like vinegar have a tendency to react with metals or plastics; hence, glass bottles are the perfect packaging materials due to their inertness toward such food items. Similarly, various medicines in liquid form are prescribed to be stored only in glass bottles. The inertness of glass is assumed due to its chemical structure, which consists of strong three-dimensional Si–O bonds. Also, glass being a completely amorphous solid with very small pore does not allow small gaseous molecules to pass through it and is perfect to store foodstuffs with aroma. Glass has several advantageous characteristics to be used as a potential material for the storage of various food items. It is 100% recyclable, transparent and completely see-through and is chemically inert. However, the major disadvantage in glass packaging is its highly brittle nature, which restricts its usage in several areas specifically related to transportation or rough handling. Besides being very brittle, glass pots become very heavy based on their structure and cannot be molded into critical shapes and sizes for various other types of packaging.

1.2.2 Metals

From the 1900s, metal cans have been used to store various foodstuffs across the world. The carbonated and non-carbonated drinks are the primary uses of metal cans as food packaging materials. Many a times foodstuffs are filled in the metal can in their hot state or in already cooked form to improve its shelf life without adding preservatives. While most of the food cans are packed at ambient pressure and temperature, beverages, beer and other carbonated drinks are packaged under pressure. The list of metals used for food packaging are aluminum, steel, tin, etc. Aluminium foil is being used in the household kitchen for wrapping food items due to its antimicrobial activity.

1.2.3 Paperboards

Paperboards are produced using bleached or unbleached natural fibers of cellulose. Various non-toxic chemical additives are added during the processing stage of paperboards to add certain functionalities in it. It can also be made out of recycled papers and pulp. Cartonboards made from paperboards are commonly used for packaging foodstuffs like liquid edibles, dry foods, frozen foods and fast food. Corrugated board is mostly used in applications of direct contact with food (e.g., pizza and burger boxes) and as secondary packaging materials. However, low molecular weight volatile and non-volatile additives and external contaminants can migrate through the packaging into the foodstuffs. Mostly mineral oils, phthalates, photoinitiators, etc. are the commonly used food additives that migrate through paperboard packages.

1.2.4 Polymer-based food packaging

The advantages of using polymeric materials for food packaging include the following: its easy processability and moldability; it can be formulated into any shape and size and hence offers consider...

Table of contents

• Title Page
• Copyright
• Contents
• 1 Sustainable polymers for food packaging: an introduction
• 2 Biobased and biodegradable polymers for food packaging: commercial status
• 3 Biobased sustainable polymers for food packaging applications
• 4 Polylactic acid for food packaging applications
• 5 Polyhydroxyalkanoates: microbially derived biodegradable polymer for food packaging applications
• 6 General material property requirement for food packaging applications
• 7 Up-to-date advances of biobased and biodegradable polymers in food packaging
• 8 Polymer blends for sustainable food packaging
• 9 Biobased biodegradable polymers in food packaging: regulations and legislations
• 10 Edible polymer-based sustainable food packaging
• 11 Trends on end-of-life options, including recycling, reusing and composting of waste food packages
• 12 Authors’ view point toward developments in biodegradable polymers to improve their versatility in food packaging
• Index