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Report 4 (of 5): Eat
Your Heart Out - Thailand
Introduction
Plastic waste causes untold damage
to the environment as well as costing governments
millions of dollars every year for disposal. Plastic
waste such as bags and food cartons often ends up
in landfill sites or discarded on the street. Incineration
of plastic waste causes toxic gases to pollute the
air. One solution to the problem is to use biodegradable
packaging that decomposes naturally and has no harmful
effects on the environment. Used in conjunction with
recycling as a means of disposal, this technology
can help reduce the millions of tonnes of plastic
waste that accumulate every year.
Choosing to address this problem head
on, two researchers at Kasetsart University's Department
of Food Science and Technology in Thailand have created
environmentally friendly food packaging using cassava
starch. This innovative product, which they named
KU Green, does not harm the environment because it
is completely biodegradable. The containers can hold
any type of food, whether hot, cold, solid or liquid,
and can be used in a microwave. The containers are
also edible! KU Green is now sold to local and international
markets under the trademark of Cassgreen.
Biodegradable Materials
When something is biodegradable, it
can be broken down by natural means into elements like
carbon, oxygen and hydrogen. The ability of a substance
to be broken down into simpler substances by bacteria
means that it can be used in household compost or as
mulch for agricultural crops.
Packaging is one industry where customers'
environmental concerns are now being heard. New research
and development into biodegradable materials has led
to products such as bags, cutlery, plates and boxes
being made of material that degrades naturally. Starch
from cassava, potatoes, corn, wheat or soy, for example,
can be used to produce food packaging that is environmentally
friendly. Starch has several advantages: it is widely
available as an agricultural surplus material, it
costs very little, and it has properties that allow
it to be processed without damaging it. Starch-based
packaging can also be given to livestock such as cows
or buffaloes to eat, or once decomposed can be used
as fertiliser for plants and trees.
Starch-based Packaging
Starch is nature's way of storing
energy. When the germ which produces a new plant begins
to grow, it depends on the starch to feed it until
it can establish roots and leaves and begin to gather
its own energy. Starch is simply sugar (glucose) that
is strung together in long chains for easy storage.
Just about every leafy plant makes some starch.
As starch is not naturally water-resistant
it needs to be mixed with other materials to improve
its performance as packaging. A big challenge has
been to offer processing characteristics as close
as possible to the traditional materials that biodegradables
are seeking to imitate or replace, such as oil-based
plastics. Products are now available that are suitable
for film blowing, casting, injection moulding and
foaming. Two different types of products have been
made by the Thai researchers from cassava starch:
film packaging and expanded packaging.
Film packaging
Cassava starch film is used as wrapping
or as sealed bags for food. These products have excellent
properties in that they are transparent; grease and
oil resistant; heat sealable; strong; and soluble
in both hot and cold water. The film is prepared from
starch solution consisting of native cassava starch
(5 per cent), sorbitol (30 per cent) and water. The
film is also edible, which makes it suitable for fatty
food packaging. In Thailand, the film is used for
wrapping sweet fruit products such as banana paste,
durian paste, and kalamae. The film has proven to
extend shelf-life of products as well as being more
practical than conventional packaging.
Expanded packaging
Expanded packaging such as fast food
trays have proven very practical for people who are
busy and on the move. Yet styrofoam or polystyrene
type packaging produces a very high quantity of waste
because it is usually used only once. KU Green packaging
solves this problem. Produced by thermal compression
moulding, it can hold water for up to 75 minutes and
liquid oil for several hours. The starch mix consists
of more than 90 per cent dry weight starch, plasticizers,
emulsifier, calcium carbonate and agar. The process
takes no more than 3 minutes at a temperature of 200-240º
Centigrade (ºC) and the product is completely biodegradable.
Cassava
Cassava (Manihot esculenta),
or tapioca as it is often known, is the third most
important crop in Thailand. About 18 to 20 million
tonnes of cassava root are produced each year from
over 1 million hectares (2.5 million acres) of planting
area. Cassava is widely grown in Thailand because
of its drought resistant properties and it can be
planted on almost any type of land. In addition to
being economically important, cassava is the cheapest
raw material for starch production.
Cassava provides a major source of
calories for poor families because of its high starch
content. With minimum maintenance, the farmers can
dig up the starchy root of the cassava and eat it
six months to three years after planting. For this
reason, people cultivate cassava during times of war
or natural disaster when no other food is available.
How to prepare cassava starch
- Wash and peel cassava tubers.
- Grate the cassava to a fine mash.
- Mix the grated cassava with a high
volume of clean water (about 10 times the mash volume).
- Remove fibres in the mash by sieving
the watery mash through a fine muslin cloth or other
fine mesh.
- Allow the fine particles of starch
to settle in water.
- Decant water from the settled starch.
- If required wash the starch again
with water to get white, odourless and tasteless
starch.
- Place the decanted starch on a
tray or the drying floor in an oven.
- Once dry, sieve the starch again
to remove any foreign material.
- Store the dry starch in an airtight
container.
Waste Disposal
Disposal of materials in an ecologically
sound manner has become an important factor in the
design of packaging. Biodegradable products must be
used in conjunction with recycling that uses biodegradation
such as composting, waste water/sewage treatment facilities,
and managed, biologically active landfills. Recycling
reduces the amount of waste going to landfill and
helps to conserve non-renewable resources. Composting
the packaging with food or garden waste is one form
of recycling that can be undertaken at home.
Composting
Recycling through composting is a
largely neglected form of waste management. Yet, for
something to be compostable, it must be biodegradable.
Composting is the accelerated degradation of various
organic matter by bacteria in a moist, warm, oxygenated
environment under controlled conditions. Composting
biodegradable products and paper waste along with
other organic compostable materials such as food and
agricultural wastes can help to generate much-needed
carbon-rich compost. Compost soil increases organic
carbon, water and nutrient retention, reducing chemical
inputs, and suppressing plant disease.
Composting is a critical process,
not only for waste management but also for maintaining
sustainable agriculture practices. Municipal waste
composting has emerged as a viable means of reducing
both the volume and proportion of waste entering landfills.
It is effectively the same as domestic composting,
but on a much larger scale. This is one way of turning
waste packaging into vital compost that can be used
for soil rejuvenation and conditioning. All KU Green
products decompose naturally and are edible, giving
a variety of options for disposal.
The Future
To minimise the adverse environmental
impact of their products, some food manufacturers
are increasingly trying to reduce the amount of packaging
used to protect their food products. KU Green packaging,
together with many other recent developments in food
packaging, has combined simple, abundant, renewable
materials, such as limestone and starch, into a material
that, like leaves and grass, is 100 per cent biodegradable
and recyclable through composting. These products
are designed to take account of the entire life-cycle
of the product (life-cycle assessment or LSA), from
conception to disposal.
All over the world, the road to ecologically
safe, consumer-friendly packaging is beginning to
have a real impact, spurred on by increasingly tougher
recycling regulations in countries such as Japan,
Europe, Australia and the USA. Supermarkets in Europe
are currently showing interest in alternative materials,
as a result of European Union moves to reduce landfill
as a method for disposal. The International Organisation
for Standardization, ISO, has also developed standards
to evaluate the biodegradability of products under
different environmental and disposal conditions such
as composting. Providing globally acceptable standards,
together with certification and logo schemes, will
help to safeguard the environment.
Glossary
Agar is extracted from certain
marine algae. It is insoluble in cold water but soluble
in boiling water. When cooled below 40°C it forms
a firm, resilient gel which melts at temperatures
greater than 80°C. This difference between gelling
and melting temperatures makes agar of great importance
in the food industry.
Calcium Carbonate is a simple
compound found in nature that occurs as a mineral
found in three crystalline forms.
Emulsifier is generally any
ingredient used to bind together substances that would
not normally combine, such as oil and water.
Plasticizer is generally a
clear, organic, liquid material that is added to a
formulation to obtain a flexible soft film to enhance
both processability and serviceability of the end
product.
Sorbitol is an alcohol sugar
that is naturally present in Mountain Ash, Hawthorn,
Plum, Pear, Apple, Seaweed and Blackstrap Molasses.
Sorbitol is used in the manufacture of 'natural vitamin
C' (ascorbic acid). It is commonly used as a nutrient
or sweetening agent.
For more information, please contact:
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Cassava Green Co. Ltd
573/67 Soi Ramkhamhaeng 39
(Thepleela 1) Ramkhamhaeng Rd
Wangthonglang, Bangkapi
Bangkok 10310
Thailand
Tel +66 2 559 0816-17
Fax +66 2 559 3962
Email: cassgreen@hotmail.com
Website: http://www.cassgreen.com/
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Suppliers of biodegradable food packaging
Websites
http://www.packaging-technology.com/
http://www.cassava.org/
Provides news, activities and statistics on starch
technology.
www.foodnet.cgiar.org/agro_ent/products/cas_re1.htm
Provides information on how to prepare different forms
of cassava, including starch, flour and leaves.
http://www.ift.org/
The Institute of Food Technologists
http://www.foodprotection.org/
The International Association of Food Protection is
comprised of a diverse membership of over 3,000 Members
from 50 nations. Members work in all areas of food
protection, industry, government, and academia.
Further Reading
Green Design
An accessible and sensible introduction to the complex
range of information available on environmentally
safe technology. It demystifies the wide range of
arguments for and against industrial and technological
solutions, analysing the central issues and citing
the failures and successes of manufacturers in addressing
environmental problems. Green Design is an essential
introduction to the subject for those involved in
manufacturing and designing.
£12.95 + £1.50 p&p from the Institute of Packaging,
ISBN 0850722845
The Institute of Packaging
Sysonby Lodge
Nottingham Road
Melton Mowbray
Leicestershire LE13 0NU
United Kingdom
Tel +44 (0)1664 502111
Email: info@iop.co.uk
Website: http://www.iop.co.uk/
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This document is an output from
a project funded by the UK Department for International
Development (DFID) and the European Commission (EC)
for the benefit of developing countries. The views
expressed are not necessarily those of DFID or the
EC.
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