Food Marketing & Technology - India May 2019 | Page 42
Packaging
they do not generally form coherent,
stand-alone films. Lipid films have
good water vapour and oxygen barrier
properties. Generally, wax coatings
are substantially more resistant to
moisture transfer than most other lipid
or non-lipid edible coatings. Edible
resins such as: shellac; terpene resin;
and wood rosin are used to impart
gloss to food commodities. Shellac
has been used extensively as an edible
coating for the confectionary and fresh
produce. Other examples of lipids that
have been used effectively in coating
formulations are: beeswax; mineral oil;
vegetable oil; surfactants; acetylated
monoglycerides; carnauba wax; and
paraffin wax.
Proteins: The films and coatings are
also made from animal and plant
proteins. The examples of the proteins
that are being used for coating fruits
and vegetables are: soy protein; whey
protein; casein; corn-zein; maize;
egg albumen; collagen; and wheat.
Like polysaccharide-based films, the
protein-based edible films also provide
excellent mechanical and barrier
properties against oxygen, aroma,
and oil. But they have very limited
resistance to water vapours.
Composite Materials: Composite
materials are a mixture of edible
components that are made to
overcome their respective flaws. The
above mentioned different forms
are not effective in preserving the
quality of the fruits and vegetables
by themselves. To improve their
effectiveness they are being used in
combinations. Most of the composite
films studied to date consist of a lipid
layer supported by a polysaccharide
or a protein layer, or lipid material
dispersed in a polysaccharide or
protein matrix. The lipid components
used in the packaging formulation
reduce water transmission while the
other components serve as selective
gas barriers and provide mechanical
strength and structural integrity; e.g.
a film prepared by combining milk
protein and lipid for lightly processed
apples and potatoes was reported to
provide protection from moisture loss
and oxidative browning for up to three
days.
Edible Film Additives
A number of materials are incorporated
into edible films to enhance structural,
mechanical and handling properties or
to provide active functions to the films.
The examples are mentioned below:
Plasticizers: To improve film flexibility
and durability, plasticizers are
generally added to edible films. These
include mono-, di-, or oligosaccharides
like glucose; fructose–glucose syrups;
and sucrose; polyols like glycerol,
sorbitol, glyceryl derivatives and
polyethylene glycols; lipids; and
derivatives like phospholipids, fatty
acids and surfactants.
Emulsifiers: Emulsifiers are essential
to achieve sufficient surface wet-ability
to ensure proper surface coverage and
adhesion to the coated surface as well
as for the formation and stabilisation of
well-dispersed lipid.
Antimicrobials: One of the important
emerging functions of edible films
and coatings is their use as carriers of
antimicrobials and antifungal agents
to increase the shelf life of foods;
they may also be used as carriers of
nutrients to increase the nutritional
value of processed food products. The
more commonly used antimicrobials
are: organic acids; chitosan; nisin;
lactoperoxidase system; and some
plant extracts and their essential oils.
Antioxidants: Antioxidants are added
to edible films to delay the start or
slow the rate of oxidation reactions.
The
examples
of
antioxidants
include:
butylatedhydroxyanisole
(BHA);
butylatedhydroxytolu-
ene (BHT); propyl gallate; tertiary
butylhydroquinone;
citric
acid;
Food Marketing & Technology
42
May 2019
ascorbic acid; ascorbylpalmitate; and
tartaric acid.
An Overview on Global Edible
Films and Coatings Market
The global edible films and coatings
market is expected to witness steady
growth owing to increased use of clean
label strategies by food producers. The
reason for the bump in the growth for
edible films and coatings is their use
as an excellent solution to reduce the
carbon footprint. As per the market
studies conducted by various market
research firms’ forecasts suggest that
this market is expected to increase by
CAGR of 7.1 percent during the period,
2018-2023. The market growth is
driven by a number of factors such as:
increasing focus on reducing wastage
from packaging material; increasing
shelf life of products; safety concerns;
increasing demand of convenient
food offerings in developed regions;
Government’s initiatives to reduce the
carbon footprint in the food sector; etc.
The benefits of edible packaging have
increased their acceptability by the
food and packaging manufacturers
and this factor is boosting revenue
growth of the global edible films and
coatings market. On the other hand
the global edible films and coatings
market is also facing challenges such
as: absence of local manufacturers of
edible films and coatings; higher cost
of edible films and coatings over the
present packaging solutions, lower
recycling cost; and restrictions on the
availability are anticipated to act as a
major restraint globally for the growth
of the edible films and coatings
market.
** Assistant Professor (SG),
Avinashilingam Institute for Home
Science and Higher Education for Women,
Coimbatore; Email: raajraajeswari@gmail.
com
* Ph.D. Scholar, Avinashilingam
Institute for Home Science and Higher
Education for Women, Coimbatore; Email:
[email protected]