Download Sustainable sourcing of natural food ingredients by plant cell cultures

Peer-reviewed scientific article
Sustainable sourcing
of natural food ingredients
by plant cell cultures
ROBERTO DAL TOSO*, FRANCESCA MELANDRI
Roberto Dal Toso
*Corresponding author
I.R.B. Istituto di Ricerche Biotecnologiche S.p.A., Via Lago di Tovel, 7, Altavilla Vicentina (VI), 36077, Italy
AgroFOOD industry hi-tech - March/April 2011 - vol 22 n 2
Functional ingredients
KEYWORDS: Plant cell cultures, eco-sustainability, phenylpropanoids, Ajuga reptans, Echinacea angustifolia.
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ABSTRACT: Plant cell cultures are a new green biotech approach for sourcing highly active plant ingredients for cosmetic
and nutritional applications, by a fully eco-sustainable process with benefits for environmental biodiversity, product quality
and end-user safety. The in-vitro cultivation of plant cells, growing in sterile and highly controlled conditions, allows to
achieve the production of phenylpropanoids (PP), also from rare or endangered species. The reduction of the
environmental impact, compared to conventional agriculture and extraction procedures, is achieved through a drastic
saving in water, extraction solvent use and negligible soil occupation, together with no use of pesticides and great
reduction of industrial waste. Benefits for end-users are a higher safety profile for the total absence of environmental
pollutants and a superior level of standardization due to strict control of the culture parameters regulating the plant cell
metabolite content.
INTRODUCTION
programmable and flexible production process.
Although well known in the scientific community, plant cell
cultures have not yet been fully developed on an industrial
scale for nutritional applications, despite their numerous
advantages over conventional methods, because of the high
level of investment required for industrial scale up and the
long period of time for product development and testing.
Safety, standardized quality and availability of non genetically
modified plant cells are the major benefits deriving from the
use of this biotechnology for the production of botanicals.
Furthermore, this process also allows to produce large
amounts of rare but extremely active plant substances,
specifically phenylpropanoids such as teupoliosde from Ajuga
reptans (3). Indeed, the first ingredient manufactured by IRB
using plant cell culture and authorized in EU as food
supplement ingredient is a dry extract of Ajuga reptans
(carpetweed) titrated in teupolioside* which has shown to be
potentially useful in reducing inflammatory processes in
gastro-intestinal alterations (4). IRB is a green biotech
company and manufacturer of natural active ingredients
from plant cell cultures for food and cosmetic applications.
Humans have always utilized plants as a major source of food
and clearly agriculture was the key development that led to
the rise in human quality of life. Development of agricultural
techniques has steadily increased agricultural productivity
and the widespread diffusion of these techniques is one of the
major achievements of mankind.
Although many technological improvements have sharply
increased yields from cultivation, at the same time, they have
imposed several external costs upon society by causing
widespread ecological modifications and negative human
health effects through pesticides, fertilizer runoff, excessive
water usage, and massive land transformation from forest to
agricultural use (1).
A major challenge in the near future will be to provide
technological advancements that help reduce the
environmental footprint and to make the use of natural
products more sustainable. One technological development
that allows to practically face this challenge is based on the
use of plant cell cultures as a source of even rare natural
substances.
This issue is clearly present to international food institutions,
such as FAO, which in 1994 endorsed the use of plant cell
*TEOSIDETM
cultures as a process to produce natural substances for
food use (2).
A second IRB extract from Echinacea angustifolia
The plant cell culture technology is based on the growth
(Asteraceae) cell cultures* (Figure 1a and 1b) has also
potential of undifferentiated plant cells in culture in the
been recognized to be “substantially equivalent” to
presence of water, essential nutrients and growth regulators.
commercially available traditional extracts and has also
The undifferentiated plant cells are
totipotent cells capable to originate all the
different tissues of the plant when properly
stimulated by external signals. Cultures of
plant cell lines are grown in sterile
bioreactors totally separated from the
environment which guarantees the absence
of frequent pollutants such as herbicides,
pesticides, heavy metals or aflatoxins with
great improvement of the safety features.
Furthermore, plant cell cultures also obviate
to geographical, climatic and seasonal
variations which plague traditional plant
Figure 1a. A flower of Echinacea angustifolia. Figure 1b. Echinacea angustifolia cell culture.
harvesting and, finally, guarantees a
been authorized in EU as food supplement ingredient by
the Committee for Dietetics and Nutrition. Also in this case
a metabolomic analysis of more than 1400 molecules
detected in the cell culture extract and in three traditional
Echinacea angustifolia products showed no qualitative,
but only quantitative differences in the composition (5).
The availability of Echinacea angustifolia extracts from
plant cell lines allows to overcome many of the variability
in the qualitative and quantitative composition of more
traditional, or even organically grown, preparations (6, 7).
*ECHIGENA PLUSTM
ENVIRONMENTAL SUSTAINABILITY
Figure 2. Usage of natural resources: comparison of traditional and IRB biotech
methods.
STANDARDIZATION, SAFETY AND NEW POSSIBILITIES
All the mentioned environmental benefits of the plant cell
culture technology are also associated with large
improvements of the products obtained.
The strict control of the culture conditions and the
continuous selection of the cell lines based on the most
important features considerably reduce the appearance of
new variants, physiological aging phenomena, and
guarantee a reproducible profile of active metabolites,
thereby overcoming the issue of variability linked to the
climatic and geographical conditions which is impossible to
solve in the traditional agricultural method. Furthermore, this
technology allows limits such as the natural biological cycle
of the plant and the seasonality of the secondary
metabolites to be bypassed, therefore guaranteeing full
availability of the constituents at all times. Even the
degradation of the active ingredients which usually occurs
during storage of the botanical material is drastically
reduced using this methodology, as the extraction
procedure is performed immediately following the
conclusion of the fermentation process.
Virtually any component or substance present in meristem
plant cells can become an ingredient for nutritional or any
other application. The most interesting use of this
biotechnology is the production of phenylpropanoids, a
class of polyphenols which are highly concentrated in
meristem cells. Echinacoside from Echinacea angustifolia is
an example, but also chicoric acid from Echinacea
purpurea, teupolioisde from Ajuga reptans or verbascoside
from Lippia citriodora are certainly compounds that can
provide a number of nutritional benefits, but are highly
limited in their availability and standardization.
As previously mentioned, Echinacea angustifolia extracts (4
percent in echinacoside) and Ajuga reptans extracts titrated
in teupolioside have been recently authorized as nutritional
AgroFOOD industry hi-tech - March/April 2011 - vol 22 n 2
The plant cell culture technology has also very important
advantages over traditional methods in terms of
environmental sustainability.
Once the plant cell line is established and optimized for a
high content of echinacoside, in case of Echinacea
angustifolia, there is no more need to cultivate other plants
in open field since cell growth is assured by the water and
nutrients supplied to the sterile bioreactor during the
process. This has deep and important implications on the
use of natural resources as shown by the comparison of the
resources, such as water, land surface and solvents, used
by traditional and biotechnological methods for the
production of 1 kg of echinacoside.
The production of 1kg of echinacoside by traditional
methods requires the cultivation of Echinacea angustifolia
plants for three, or four, years so that the proper root size
and the balsamic period of maturation is reached (see
Figure 2). On the average roughly 1.3 metric tons of dry roots
Functional ingredients
As an example, the concentration of echinacoside in
Echinacea angustifolia are strongly dependent on the
environmental conditions under which the plant is grown.
These, unfortunately are numerous and intrinsically
variable. Indeed, the mineral and organic composition of
the soil, including the microflora present, both general and
micro-climatic conditions, seasonal variations and
phytochemical treatments can all affect the secondary
metabolite content, as well as differences of the genetic
background of the plants themselves. As all these factors
are directly correlated to the final concentration and daily
dose of the active substances utilized by final users, these
considerable differences can be of great concern (6).
are collected for hectare (ha) of cultivated land (8). Each
dry root contains on the average 1 percent of echinacoside,
but in some cases can reach up to 2 percent of
echinacoside. Taking into consideration this last
overestimated case, provides a yield of 26 kg/ha in three
years which means 8.7 kg/ha per year. This provides the final
figure of 1149m2 of soil used for the production of 1 kg of
echinacoside. A similar calculation shows that, in the same
period of time, the amount of water required for plant
growth (9) for photosynthesis, biomass, plant
evapotranspiration, evaporation and soil percolation
provides the amount of 1379 metric tons per kg of
echinacoside. Finally, echinacoside needs also to be
extracted from the roots and this requires approximately 500
litres of organic solvents to be used.
When the biotechnological process based on plant cell
cultures of Echinacea angustifolia is used to produce 1 kg of
echinacoside (see Figure 2), the surface required covers only
3 m2 and the amount of water to be used is 1 metric ton thus
saving resources for primary uses and mainly for food
production. Finally the amount of solvents employed to
extract the compound is 100 litres.
The difference involved in the use of natural resources is
clear and very significant.
Other important advantages of the biotech process over the
traditional approach in the extraction of active botanical
substances are the total absence of pesticide use and the
fact that no other plant is collected from the environment
which, in case of endangered botanical species or very low
level substances, is an important element to preserve
biodiversity and ecological balance.
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supplement ingredients in the EU. This highlights that the new
process based on plant cell cultures is in the condition to
meet and satisfy the strict safety and quality standards
required to preserve consumer health. But besides
phenylpropanoids, also very complex components such as
polysaccharides from plant cell cultures of Echinacea
purpurea (10) have been shown to reproduce in vivo the
well-known immune-stimulatory effect described for the
extracts of plant aerial parts and widely used for cold and flu
prevention.
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Functional ingredients
CONCLUSIONS
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The technology based on plant cell cultures, fine-tuned by
IRB, offers a potentially unlimited availability of natural
substances, even rare, that have been yet utilized in limited
amounts for nutritional application. This combines with a
largely improved and reproducible safety profile, a
standardized composition and an extremely low
environmental impact, as compared with traditional
extraction methods. The result is the possibility to utilize
scarcely available, but highly active substances as nutritional
supplements with truly significant benefits for both
environmental and human wellness.
REFERENCES AND NOTES
1.
Epa gov., Human Health Issues | Pesticides | US EPA, ( 2006).
http://www.epa.gov/opp00001/health/human.htm. Retrieved
2009-11-26.
2. M. Misawa, Plant Tissue Culture: an alternative for production of
useful metabolite, 108, (1994).
3. R. Dal Toso, F. Melandri, Nutrafoods, 8(2), pp. 17-24 (2009).
4. R. Di Paola, E. Esposito et al., Biochemical Pharmacology, 77, pp.
845-857 (2009).
5. R. Dal Toso, F. Melandri, Nutrafoods (2011).
6. R. Krochmal et al., Phytochemical assays of Commercial
Botanical Dietary Supplements eCAM, 1(3), pp. 305-313 (2004).
7. Letchamo J. Janick et al., Trends in new crops and new uses,
ASHS Press, pp. 514-521 (2002).
8. U. Bomme, D. Nast, Zeitschrift für Arznei- und Gewürzpflanzen (3),
pp. 82-90 (1998).
9. G. Nebbia, Internatioanl Water Culture Center, University of
Rome (2004).
10. C. Steinmüller, J. Roesler et al., International Journal of
Immunopharmacology, 15(5), pp. 605-614 (1993).