Bioactive compounds – added value for potato from genetic resources
and waste streams
Veli-Matti Rokka1, Tatjana Gavrilenko2, Elina Virtanen3, Jari P.T. Valkonen4
1MTT Agrifood Research Finland, Biotechnology and Food Research, Myllytie 1, FI31600 Jokioinen, Finland, tel: +358 3 4188 2497, e-mail: veli-matti.rokka@mtt.fi ,
2N.I. Vavilov Institute of Plant Industry (VIR), St.-Petersburg, Russia, 1MTT Agrifood
Research Finland, Biotechnology and Food Research, Tutkimusasemantie 15, FI-92400
Ruukki, Finland, 4Department of Agricultural Sciences, P.O. Box 27, FI-00014
University of Helsinki, Finland
Introduction
A new research project starting in August 2010 is focused on analyses,
characterisation and utilisation of bioactive compounds from various genetic resources
of potato and waste streams and by-products from potato industry. Potato tubers
contain plenty of bioactive compounds including proteins, peptides, carotenoids,
polyamines, polyphenols, suberins, glycoalkaloids and dietary fibre. Most of them
enhance human health and they all are useful components for food industry.
The present project aims to select for use, novel potato materials rich in the content of
bioactive compounds and improve utilization of by-products and waste resulting from
the current processes of potato industry. Results are foreseen crucial for development
of new potato products for domestic and export markets.
Added value from potato
Potato is well known for its favourable nutritional properties. It also contains various
compounds with high bioactivity, most of them located in the potato skin or on first
cell layers under the skin.
Potato covers a rich reservoir of genetic variation, since there are even more than 200
tuberizing species. Some of those, such as S. ajanhuiri, S. chaucha, S. juzepczukii, S.
curtilobum, S. phureja, S. stenotomum, S. stenotomum ssp. goniocalyx, S. tuberosum
ssp. andigenum and S. tuberosum ssp. tuberosum have traditionally been grown by
farmers in the Andes of South America. In Europe, we only have a few exceptions of
products which are originated from other potato species than S. tuberosum, i.e.
cultivated potato). The native potato species (NPS) have an intrinsic value based on
their heterogeneous genetic background, which also offers plasticity to environmental
changes (Ritter et al. 2008). In addition, the diversity of the traditional material brings
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new challenges and alternatives for development of novel products, which may have
important markets as special food products, i.e. potato to be used as a value-added
product.
The germplasm collections of VIR (Vavilov Institute) of St. Petersburg, Russia,
represents the first botanic and scientific collection made for potatoes, today
numbering 8,680 different accessions (Gavrilenko 2008). It has tremendous practical
importance and a rich history, having been used to document a polyploid series in the
cultivated species, to formulate initial taxonomic hypotheses in potato, for studies of
interspecific hybridization, and serving as the base for Russian breeding efforts. The
material is morphologically and genetically well evaluated. However, the VIR potato
collection of cultivated potatoes have been poorly characterized from a nutritional and
phytochemical perspective.
Industrial by-products and wastes
In Finland, a total amount of 300 M kg of table potatoes are produced. Of that, 7080% can be utilised for processing in food industry. The remaining peel waste is used
for animal feed or improving of soil. Potato peels are specially rich in steroidal
glycoalkaloids (SGAs), including solanine and chaconine. Extracted glycoalkaloids from
potato skin may be commercially important based on their pharmaceutical activities
because of the structural resemblance to the human sex hormones. Particular SGAs
can be transformed into steroidal drugs, and their high cytotoxic activities as anticancer
compounds have recently received strong scientific interest (Väänänen et al.
2005).
Conclusions
Exotic potatoes other than S. tuberosum ssp. tuberosum cultivars may have a high
interest in terms of commercialization in Russia and in Europe. In Finland, on the
market there is already one potato cultivar called Blue Congo, which has a dark purple
skin also with a purple flesh. This clearly shows that potatoes even with considerably
irregular shape and completely exceptional flesh colour can have market potential.
Some potato species are known to have high protein content in tubers, which is also
important for need of production in developing countries. Certain genotypes can be
valuable sources of vitamins, dietary fibre and certain minerals such as copper,
potassium, iron and magnesium. Potatoes may also contain a broad variation of
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phytonutrients that have antioxidant capacity. Among the health-promoting
compounds there are carotenoids, flavonoids, caffeic acid and tuber storage protein
patatin, which exhibit activity against free radicals and have antimicrobial, antiinflammatory
and antiallergic properties (Brown et al. 2007, Ritter et al. 2008).
Potatoes earlier cultivated only by American Indians can offer a high reservoir for
developing novel products. Some tubers may have colored flesh, which can be a useful
new criterium for potato crisp production. Determinations of dry matter content, chip
colour, oil absorption and cooking time are important for potato processing. Low oil
content associated with high dry matter and consistent chip colour are favourable to
economic and health concerns (Ritter et al. 2008). Therefore NPS potatoes are a great
source of high quality french fries and crisps. Excellent flavours and attractive colours
with variable shapes may result in products with novelty appeal. Some genotypes of
NPS collection may also show inhibition of the angiotensin converting enzyme I (ACE),
a biochemical factor which has an effect on blood pressure (hypertension) (Mäkinen et
al. 2008).
References
Väänänen, T., Ikonen, T., Rokka, V.-M., Kuronen, P., Serimaa, R. & Ollilainen, V.
2005. Influence of incorporated wild Solanum genomes on potato properties in terms
of starch nanostructure and glycoalkaloid content. J. Agric. Food Chem. 53: 53135325.
Brown, C.R., Culley, D., Bonierbale, M. & Amoros, W. 2007. Anthocyanin, carotenoid
content, and antioxidant values in native South American potato cultivars. HortSci. 42:
1733-1736.
Gavrilenko, T. 2008. Ex situ conservation of plant genetic resources in Russia: history,
current status and perspectives. In: Cryopreservation of crop species in Europe.
CRYOPLANET – COST Action 871. Febr 20th-23rd 2008. Oulu, Finland.
Mäkinen, S., Kelloniemi, J., Pihlanto, A., Mäkinen, K., Korhonen, H., Hopia, A. &
Valkonen, J.P.T. 2008. Inhibition of angiotensin converting enzyme I caused by
autolysis of potato proteins by enzymatic activities confined to different parts of the
potato tuber. J. Agric. Food Chem. 56: 9875-9883.
Ritter, E., Barandalla, L., Lopez, R. & de Galarreta, J.I. 2008. Exploitation of exotic,
cultivated Solanum germplasm for breeding and commercial purposes. Potato Res. 51:
301-311.
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