Edible Films Made Of Kefiran: A Brief Review
Eluith Eliu Vélez González. CITA-6005. Food Packaging. Food Science and Technology
Program. University of Puerto Rico. Mayaguez Campus
Abstract
Edible films are thin layers of materials used to protect and preserve some types of food.
These films are made principally from agricultural and wastes and other biodegradable
materials. Therefore, the use of edible packaging materials reduces the negative environmental
impact caused by the ever-increasing use of synthetic plastic materials on food packaging.
Recently, the use of kefiran, a bacterial produced extracellular polysaccharide with numerous
alleged functional properties has been proposed as a material for the production of edible films
and coatings. This work provides a brief review of the available literature on the properties and
production of edible films based on kefiran, which arise as a new alternative material but its
application require more deeply investigations on its capacity for food preservation.
Keywords: edible film, plastic, polysaccharide, kefiran, kefir, plastic
Introduction
environment; being food wraps responsible
The preservation and protection of
of millions of tons every year (Parra et al.,
all types food and raw material used in food
2004; Espitia et al., 2013). The great
production, particularly form microbial and
majority of these plastics are crude oil
oxidative damage, as well as the extension
based, and therefore, the increased plastic
of food shelf life are concerns of the food
production leads to an increase in the use of
packaging industry (Taharanthan, 2003), in
oil, which is a scarce resource, and also
which the most used materials used to
causes
preserve foodstuff are synthetic, principally
damages due to the pollution associated
plastics (Perez-Mateos et al., 2007). A 25-
with their production and the accumulation
fold increase in the world plastic production
of wastes and non-degraded polymers
over the last twenty years have been
(Parra et al., 2004). Therefore, being aware
caused by the increased use of synthetic
of
materials and lead to yearly production of
damage, the scientific community have
nearly 150 million tons of plastic, from which
bring some new alternatives to reduce the
less than 5% is recycled and therefore leads
use of synthetic materials, from which the
to a rapid accumulation of plastics in the
use of edible films and coatings, particularly
the
very
serious
abovementioned
environmental
environmental
1
in the food industry, arises as one of the
serve as carriers of food aditives for the
most promising ones (Aider et al., 2010).
extension of shelf life (Elsabee and Abdou,
Edible films and coatings are thin
and continuous layers of edible material that
are placed on or between foods or its
components (Bravin et al., 2006). Although
the terms edible film (EF) and edible coating
(EC) are often used as synonyms (Azeredo,
2012), in a more strict manner, EC’s are
films applied to the food in a liquid state,
usually by immersion of the food in a
solution, while EF’s are pre-formed as
sheets and then applied as wrapping to the
food product (Falguera et al., 2011). The
major constituents of these films are lipids,
proteins
and
polysaccharides
obtained
mainly form agricultural sources and waste
products from the food industry (Maqbool et
al., 2010). These films have a wide range of
applications in the food industry, particularly
on those highly perishable foods such as
fruits and vegetables (Maqbool et al., 2010),
where
films
play
important
roles
in
conservation, distribution and marketing;
protecting
the
food
physical,
chemical
damage,
and
from
and
mechanical,
microbiological
preventing
quality
deterioration by acting as a barrier for
moisture, gases (oxygen), lipids and flavors
2013; Vasconez et al., 2009). However,
their
main
advantage
over
synthetic
materials is that, as the term indicates, EF’s
and EC’s are edible; and even if not eaten,
the fact that these films are made from
entirely renewable materials cause them to
degrade
more
environmental
easily,
reducing
the
pollution
caused
by
accumulation of synthetic plastic materials
and also reduce the CO2 emissions related
to their production (Bourtoom et al., 2008;
Parra et al., 2004). Therfore, due to the
potential of edible materials to the reduction
of
environmental
damages
and
their
numerous potential uses in foodstuffs, many
novel materials and techniques have been
recently developed, and one of the most
recent approach towards edible films have
been the use of natural antimicrobial
compounds to their prodution (Maqbool et
al., 2010). Probably the most widely studied
and used natural antimicrobial compound is
chitosan (Elsabee and Abdou, 2013); but in
recent years, some studies have been
made on the development of films of a
bacterial produced polysaccharide named
kefiran.
(Falguera et al., 2011; Ghasemlou et al.,
Kefiran is water soluble extracellular
2011a). Also, the films offer advantages
polysaccharide (EPS) produced by the lactic
such
biocompatibility,
acid bacteria Lactobacillus kefiranofaciens
esthetic appearance, low cost and can
(Farnworth and Mainville, 2003). It is
as
non-toxicity,
2
obtained from kefir grains, the natural
et al., 2009;Vinderola et al., 2006), among
starter for the production of kefir, a slightly
others.
effervescent and acidic fermented milk
originated from the Caucasus Mountains of
the
former
Soviet
numerous
Union
alleged
have
The possibility of using kefiran as an
benefits
alternative material for the production of
which
health
Films Based on Kefiran
(Farnworth and Mainville, 2003). Because
edible
LAB and their products are generally
studies made by Piermaria et al. (2008),
recognized as safe (Piermaria et al., 2008)
which
and because it shows interesting properties
properties of the EPS and found that, when
such as gelling and emulsifier capabilities,
in diluted solutions, it shows a Newtonian
kefiran have gained much interest over the
behavior and becomes pseudoplastic at
last
possible
high concentrations, and it forms translucent
applications on foods, particularly on the
and self-supporting (sufficiently cohesive to
production of edible films (Ghasemlou et al.,
support their own weight) cryogels (gels that
2012). The use of kefiran as a material for
are formed after cryogenic treatment) that
the
some
have good water-holding capacity and melt
advantages such a relatively easy extraction
at mouth temperature. Later, the same
method
extraction
authors (Piermaria et al., 2009) where the
(Piermaria et al., 2008, 2009) and a high
firsts to report of the use of EPS from lactic
yield EPS production from kefir grains or its
acid bacteria for the making of edible films
LAB cultures using non-expensive waste
when they investigate the use of the kefiran
material such as whey from milk and
for
cheese
and
characteristics such as transparency, plate
Radchabut, 2011; Ghasemlou et al., 2012).
remotion easiness and flexibility, found that
Also, probably the main advantage of the
the optimum concentration of kefiran in
use of kefiran on EF’s are the health
aqueous solution for the making of films to
benefits related to its consumption, which
be
includes anti-inflammatory (Morera et al.,
rheological
2008), anti-pathogenic (Bafrbosa et al.,
forming solutions, which determine the
2009; Medrano et al., 2008; Rodrigues et
processing conditions and machinability for
al., 2005), anti-tumorgenic (Rizk et al.,
film obtention at industrial scale and found
2008) and immunomodulating activity (Hong
that,
few
years
production
with
due
of
a
EF’s
high
processing
to
its
offers
purity
(Cheirslip
packaging
studied
that
10
some
manner
g/kg.
materials
based
they
characteristics
without
concentration,
regarding
all
the
from
physicochemical
and,
Also,
arise
on film
studied
of
the
the
tested
the
film
EPS
solutions
3
exhibited a pseudoplastic behavior. They
edible films and the effects of glycerol as a
also tested the addition of glycerol as a
plasticizer where confirmed by Ghasemlou
plasticizer (to increase flexibility of films)
et al. (2011), which studied the effects of
and found that water activity, humidity, and
different concentrations of the plasticizer on
loss of the water vapor barrier properties of
film characteristics and reported that, apart
the films increase parallel with an increase
from the above mentioned effects, as
in glycerol concentration; and that addition
glycerol
of the plasticizer do not affect properties
extensibility of the films increase while the
such as apparent viscosity of the film-
tensile strength decrease, which implies a
forming
higher mobility of the film; and that, in a
solutions
and
film
thickness
concentration
similar
results, they suggest that for optimum film
temperature of the films (temperature where
properties,
25g of
a change or transition from an amorphous
glycerol for every 100g of the EPS should
solid state to a more viscous state is
be used. Furthermore, in a later report
observed) decreased as a result of the
(Piermaria et al., 2011) the authors studied
plasticization imparted by an increase in the
the effects of the use of sugars (glucose,
plasticizer concentration. Later, based on
galactose
polyols
the results of a study made to observe the
(glycerol and sorbitol) as plasticizer agents
effects of the use of polyols as plasticizers,
on kefiran films and found that, while kefiran
the same authors also support the results
films
the
reported by Piermaria et al. (2011) by
plasticizers improved film properties and
concluding the use of glycerol might be
that all films could confer protection against
more suitable plasticizer for the production
microorganisms due to the low aw presented
of kefiran films than sorbitol, and that the
by the films (<0.5). Also, their results
plasticizer effects of glycerol became less
showed that, of all tested plasticizers, the
significant when testing film characteristics
lowest permeability value and the best
such as tensile strength and puncture
mechanical properties were obtained when
deformation (Ghasemlou et al., 2011b).
using glucose and glycerol, respectively
Later, Ghasemlou et al. (2011c) in an
(Piermaria et al., 2011).
attempt to reduce the strong hydrophobicity
and
where
sucrose)
britter
and
and
rigid,
all
The reports of Piermaria et al. (2008,
2009, 2011) on the possibility of the
incorporation of kefiran for the production of
the
glass
the
(Piermaria et al., 2009). Based on their
a concentration of
manner,
increase,
transition
exhibited by films, which is one of the major
drawbacks of natural films when compared
to synthetic ones, and found that the water
vapor permeability of the films was reduced
4
approximately by 33% with the addition of
properties. However, the limited available
oleic acid, which also reduces the film
literature on kefiran based EF’s evidence
tensile
the
the need of further studies on its properties,
elongation capabilities of the films. Also,
possible uses and benefits before its
according Motedayen et al. (2013), the
application
water
preservation of food.
strength
vapor
and
increases
permeability properties of
kefiran films can be increased, to some
extent, by the addition of corn starch. Lastly,
one more report on kefiran edible films was
found in the literature, a study made by Pop
et al. (2013) on the effects of the use of
glycerol as a plasticizer and reported that
the addition of glycerol in an optimum
concentration of 7% w/w resulted in films
with the best transparence and elastic
characteristics
Conclusion
The use of edible and biodegradable
packaging materials appears to be one of
the most promising alternatives to reduce
for
the
protection
and
References
Azeredo, H.M. C. (2012). Ch.14: Edible
Coatings. In. Rodrigues, S., and
Fernandes,
F.
A.
N.
(Eds.).
(2012). Advances in fruit processing
technologies (Vol. 23). CRC Press.
Barbosa, A. F., Santos, P. G., Lucho, A. M.
S., & Schneedorf, J. M. (2011). Kefiran
can disrupt the cell membrane through
induced pore formation. Journal of
Electroanalytical
Chemistry, 653(1),
61-66.
Bourtoom, T. (2008). Edible films and
coatings:
characteristics
and
properties.International Food Research
Journal, 15(3).
the costs and environmental damages
caused by the increased accumulation of
plastics and synthetic materials used for
food packaging. The demand of consumers
for more natural products without the use of
chemical
preservatives
has
lead
researchers to look for natural alternatives,
where bacterial polysaccharides such as
kefiran
appear
as
new
alternatives.
Physicochemical properties of EF’s based
on kefiran make them a good choice for
Bravin, B., Peressini, D., and Sensidoni, A.
(2006). Development and application
of polysaccharide–lipid edible coating
to extend shelf-life of dry bakery
products. Journal
of
Food
Engineering, 76(3), 280-290.
Cheirsilp, B., & Radchabut, S. (2011). Use
of whey lactose from dairy industry for
economical kefiran production by
Lactobacillus kefiranofaciens in mixed
cultures
with
yeasts.
New
biotechnology, 28(6), 574–80.
food applications, which also provides extra
advantages such as its numerous functional
Elsabee, M. Z., & Abdou, E. S. (2013).
Chitosan based edible films and
5
coatings: A review. Materials Science
and Engineering: C.
Espitia, P. J. P., Du, W. X., Avena-Bustillos,
R. D. J., Soares, N. D. F. F., &
McHugh, T. (2013). Edible Films from
Pectin:
Physical-Mechanical
and
Antimicrobial Properties- A Review
Food Hydrocolloids.
Falguera, V., Quintero, J. P., Jiménez, A.,
Muñoz, J. A., and Ibarz, A. (2011).
Edible films and coatings: structures,
active functions and trends in their
use.Trends in Food Science &
Technology, 22(6), 292-303.
Farnworth, E.R.; and Mainville, I. (2003).
Kefir: a fermented milk product. In.
Farnworth, E. R. (Ed.). Handbook of
fermented functional foods. Boca
Raton, Florida: CRC Press, 200, 77111.
Ghasemlou, M., Khodaiyan, F., Oromiehie,
A., & Yarmand, M. S. (2011a).
Development and characterisation of a
new biodegradable edible film made
from kefiran, an exopolysaccharide
obtained from kefir grains. Food
Chemistry,127(4), 1496-1502.
Ghasemlou, M., Khodaiyan, F., and
Oromiehie, A. (2011b). Physical,
mechanical, barrier, and thermal
properties
of
polyol-plasticized
biodegradable edible film made from
kefiran. Carbohydrate Polymers, 84(1),
477-483.
Ghasemlou, M., Khodaiyan, F., Oromiehie,
A., & Yarmand, M. S. (2011c).
Characterization of edible emulsified
films with low affinity to water based on
kefiran and oleic acid. International
Journal of Biological Macromolecules,
49 (3), 378-384.
Ghasemlou, M., Khodaiyan, F., Jahanbin,
K., Gharibzahedi, S. M. T., and Taheri,
S. (2012). Structural investigation and
response surface optimisation for
improvement of kefiran production yield
from a low-cost culture medium. Food
Chemistry, 133(2), 383-389.
Hong, W. S., Chen, H. C., Chen, Y. P., and
Chen, M. J. (2009). Effects of kefir
supernatant and lactic acid bacteria
isolated from kefir grain on cytokine
production
by
macrophage. International
Dairy
Journal, 19(4), 244-251.
Maqbool, M., Ali, A., Ramachandran, S.,
Smith, D. R., & Alderson, P. G. (2010).
Control of postharvest anthracnose of
banana using a new edible composite
coating. Crop Protection, 29(10), 11361141.
Medrano, M., Pérez, P. F., and Abraham, A.
G.
(2008).
Kefiran
antagonizes
cytopathic effects of Bacillus cereus
extracellular
factors.
International
journal of food microbiology,122(1), 17.
Moreira, M. E., Santos, M. H., Pereira, I. O.,
Ferraz, V., Barbosa, L. C., and
Schneedorf, J. M. (2008). Antiinflammatory activity of carbohydrate
produced from aqueous fermentation
of kefir. Química Nova, 31(7), 17381742
Motedayen, A. A., Khodaiyan, F., and
Salehi, E. A. (2013). Development and
6
characterisation of composite films
made of kefiran and starch. Food
chemistry,
136(3-4),
1231–8.
doi:10.1016/j.foodchem.2012.08.073
Parra, D.F.; Tadini, C. C.; Ponce, P.; and
Lugão, A.B. (2004). Mechanical
properties
and
water
vapor
transmission in some blends of
cassava
starch
edible
films. Carbohydrate Polymers, 58(4),
475-481.
Pérez-Mateos, M., Montero, P., and
Gómez-Guillén,
M.
C.
(2009).
Formulation
and
stability
of
biodegradable films made from cod
gelatin and sunflower oil blends. Food
Hydrocolloids, 23(1), 53-61.
Piermaria, J. A., de la Canal, M. L., and
Abraham, A. G. (2008). Gelling
properties of kefiran, a food-grade
polysaccharide obtained from kefir
grain.Food Hydrocolloids, 22(8), 15201527.
Pop,
C., Apostu, S., Rotar, A. M.,
Semeniuc, C. A., Sindic, M., & Mabon,
N.
(2013)
FTIR
spectroscopic
characterization of a new biofilm
obtained from kefiran. Journal of
Agroalimentary
Processes
and
Technologies 19(2), 157-159
Rizk, S., Maalouf, K., and Baydoun, E.
(2009). The antiproliferative effect of
kefir cell-free fraction on HuT-102
malignant
T
lymphocytes. Clinical
Lymphoma and Myeloma, 9, S198S203.
Rodrigues, K. L., Caputo, L. R. G.,
Carvalho, J. C. T., Evangelista, J., &
Schneedorf, J. M. (2005). Antimicrobial
and healing activity of kefir and kefiran
extract.
International
journal
of
antimicrobial agents,25(5), 404-408.
Tharanathan, R. N. (2003). Biodegradable
films and composite coatings: past,
present and future. Trends in Food
Science & Technology, 14(3), 71-78.
Piermaria, J. A., Pinotti, A., Garcia, M. A.,
and Abraham, A. G. (2009). Films
based
on
kefiran,
an
exopolysaccharide obtained from kefir
grain:
Development
and
characterization. Food
Hydrocolloids, 23(3), 684-690.
Vásconez, M. B., Flores, S. K., Campos, C.
A., Alvarado, J., and Gerschenson, L.
N. (2009). Antimicrobial activity and
physical properties of chitosan–tapioca
starch based edible films and
coatings. Food
Research
International, 42(7), 762-769.
Piermaria, J., Bosch, A., Pinotti, A.,
Yantorno, O., Garcia, M. A., &
Abraham, A. G. (2011). Kefiran films
plasticized with sugars and polyols:
water vapor barrier and mechanical
properties
in
relation
to
their
microstructure analyzed by ATR/FT-IR
spectroscopy. Food
Hydrocolloids, 25(5), 1261-1269.
Vinderola, G., Perdigón, G., Duarte, J.,
Farnworth, E., and Matar, C. (2006).
Effects of the oral administration of the
exopolysaccharide
produced
by
Lactobacillus kefiranofacienson the gut
mucosal
immunity. Cytokine,36(5),
254-260.
7