Optimisation of barley and buckwheat processing for sustainable use in high quality functional foods

Project co-financed by:

ARRSLogo 2016

Participating reserach organisations: 

  • Nutrition Institute, Ljublajna (leading organisation)
  • University of Ljubljana, Biotechnical Faculty
  • Slovenian Forestry Institute


  • Slovenian Research Agency (ARRS - SRA) [SICRIS]
  • Valens INT d.o.o.

Project operation:

  • 1. 3. 2016-28. 2. 2019

Project leader:

  • prof. dr. Ivan Kreft

Description of the project:

In Slovenia and in Europe it is a problem that in the processing of cereals and non-cereal grain for conventional or functional food products, large quantities of by-products end up as animal feed or even waste. In food processing industries that generate voluminous by-products and wastes, valorisation can help facilitate the sustainable use of available natural resources, and offset growing environmental and food security problems. Furthermore, there is a series of underexploited opportunities for use of buckwheat and barley fractions to increase nutritional and overall quality of foods. To communicate nutritional and/or health benefits to consumers, the effects need to be sufficiently substantiated scientifically.

Project goals

  1. To develop state-of-the-art processing techniques for common and Tartary buckwheat and barley that will enable the production of attractive functional ingredients (rich in flavonoids, peptides and quality protein, fibre, etc.), with special attention to optimal utilisation of grain, including the utilisation of by-products.
  2. To exploit the use of such functional ingredients for production of high quality food products, which need to be attractive to consumers. 

A new research and technological approach is suggested:

Grain processing techniques: Novel milling and particle separation techniques to produce materials and by-products, and the spectra of possible products that could be derived from them. Grain fractions will be minced by disc mills and a combination of diverse milling techniques. Afterwards air flow separation will separate particles into fractions with diverse chemical composition.

Use of functional ingredients in foods: Diverse uses of grain fractions will be exploited. One way of preparing bread involves sourdough fermentation, which can be accompanied by the formation of flavour compounds such as lactic and acetic acid, which have an impact on dough processing and preparing of sourdough bread. Cereals can be processed by sourdough fermentation into foods suitable for consumption. The hydrolysis of proteins and possibly starch during sourdough fermentation has an impact on elasticity observed in the sourdough. Sourdough lactic acid bacteria were shown to have the capacity to release peptides with antioxidant activity through the proteolysis of cereal proteins.

The combined effects of sourdough fermentation and the baking process on the flavonoid concentration and antioxidant properties of sourdough, bread dough, and sourdough bread have not yet been studied. The use of buckwheat and barley in bread and other foods contributes to the reduction of the rise in blood glucose after a meal; however, it is not clear under which conditions such an effect is sufficient to the extent that its communication would be relevant for the consumer. For example, strict food regulations in the EU (Reg. EU 1924/2006) currently limit such a barley-related claim to foods that contain at least 4 g of beta-glucans from barley for each 30 g of available carbohydrates. Meeting such conditions in products that would be acceptable for consumers is currently not possible. It is therefore very important to investigate, whether lowering the glycaemic response can also be observed in different conditions.

The work related to buckwheat and barley is expected to result in a new segment of high quality products with added value: these will be offered to the global market and help the company grow and compete more successfully. In this way the project will also support the Slovenian economy. Furthermore, development of high quality foods is important for society and will support public health, both nationally and globally.


The use of barley and Tartary buckwheat is a new way towards the sustainable production of functional food. Knowledge on nutritional value of individual milling fractions and products of common buckwheat and barley, obtained by modern milling and separation methods, was up to now very limited, the project is broadening this knowledge.

A feasible and environment friendly processing of barley and buckwheat was established to obtain functional food products. We also pointed out the content and concentrations of bioactive substances from the point of view of use for human food, especially for bread and some other food products. In Tartary buckwheat we reported the relation of flavonoids content with the content of other nutritionally relevant metabolites, proteins, tannins and fagopyrin. In barley interrelation of grain botanical structures and beta-glucans concentration was reported.

The management of the glycemic response is very interesting property of beta-glucans. Research on this topic is also very important for the food industry. Existing evidence was strong enough to enable approval of the health claim that consumption of β-glucans as part of a meal contributes to the reduction of the blood glucose rise after that meal, but such a claim may be used only for food which contains at least 4 g of β-glucans for each 30 g of available carbohydrates in a quantified portion as part of the meal. Using existing techniques the food industry cannot successfully produce functional foods that would meet such conditions, indicating that further research is needed. We conducted a clinical study to determine, if beneficial health effects can be also observed with lower content of beta-glucans. Results of the project showed that beneficial role of lowering glycaemic response is already achieved with notably lower amount of beta-glucans. These results can be used in substantiation of the need for change of the EU legislation.

The development of several new functional food products is suggested.


  • CAJZEK, Florijan, BERTONCELJ, Jasna, KREFT, Ivan, POKLAR ULRIH, Nataša, POLAK, Tomaž, POŽRL, Tomaž, PRAVST, Igor, POLIŠENSKÁ, Ivana, VACULOVÁ, Kateřina, CIGIĆ, Blaž. Preparation of [beta]-glucan and antioxidant-rich fractions by stone-milling of hull-less barley. International journal of food science & technology. [Online ed.]. 2020, vol. 55, iss. 2, str. 681-689, ilustr. ISSN 1365-2621
  • GERM, Mateja, ÁRVAY, Július, VOLLMANNOVÁ, Alena, TÓTH, Tomáš, GOLOB, Aleksandra, LUTHAR, Zlata, KREFT, Ivan. The temperature threshold for the transformation of rutin to quercetin in Tartary buckwheat dough. Food chemistry, ISSN 0308-8146. [Print ed.], 2019, vol. 283, str. 28-31, doi: 10.1016/j.foodchem.2019.01.038. [COBISS.SI-ID 9146233], 
  • BONAFACCIA, Giovanni, MERENDINO, Nicolò, BONAFACCIA, Francesco, MOLINARI, Romina, GALLI, Vincenzo, PRAVST, Igor, ŠKRABANJA, Vida, LUTHAR, Zlata, GOLOB, Aleksandra, GERM, Mateja. Concentration of proteins, beta-glucans, total phenols and antioxidant capacity of Slovenian samples of barley = Vsebnost proteinov, beta-glukanov, skupnih fenolov in antioksidativna vrednost slovenskih vzorcev ječmena. Folia biologica et geologica, ISSN 1855-7996. [Tiskana izd.], 2016, letn. 57, št. 3, str. 11-18. [COBISS.SI-ID 8625529]. 
  •  KOČEVAR GLAVAČ, Nina, STOJILKOVSKI, Katja, KREFT, Samo, PARK, Cheol Ho, KREFT, Ivan. Determination of fagopyrins, rutin, and quercetin in Tartary buckwheat products. Lebensmittel-Wissenschaft + Technologie, ISSN 0023-6438, 2017, vol. 79, str. 423-427, ilustr. http://www.sciencedirect.com/science/article/pii/S0023643817300804, doi: 10.1016/j.lwt.2017.01.068. [COBISS.SI-ID4284017], 
  •  ZHOU, Meiliang, SUN, Zhanmin, DING, Mengqi, LOGACHEVA, Maria D., KREFT, Ivan, WANG, Dan, YAN, Mingli, SHAO, Jirong, TANG, Yixiong, WU, Yanmin, ZHU, Xuemei. FtSAD2 and FtJAZ1 regulate activity of the FtMYB11 transcription repressor of the phenylpropanoid pathway in Fagopyrum tataricum. The New phytologist, ISSN 0028-646X, 2017, vol. 216, iss. 3, str. 814-828, doi: 10.1111/nph.14692. [COBISS.SI-ID 8758137], [JCRSNIPWoS do 9. 9. 2018: št. citatov (TC): 1, čistih citatov (CI): 1, čistih citatov na avtorja (CIAu): 0.10, Scopus do 29. 12. 2018: št. citatov (TC): 2, čistih citatov (CI): 2.
  • GRAŠIČ, Mateja, ORAŽEM, Maja, GOLOB, Aleksandra, VOGEL-MIKUŠ, Katarina, GABERŠČIK, Alenka. Water shortage reduces silicon uptake in barley leaves. Agricultural water management, ISSN 0378-3774. [Print ed.], 2019, vol. 217, str. 47-56, doi: 10.1016/j.agwat.2019.02.030. [COBISS.SI-ID 5002063], [JCRSNIP] kategorija: 1A1 (Z, A', A1/2); uvrstitev: SCI, IF=3,1. Zeleni deli rastlin ječmena, sestava in možna uporaba v prehrani.
  •  GERM, Mateja, STIBILJ, Vekoslava, ŠIRCELJ, Helena, JERŠE, Ana, KROFLIČ, Ana, GOLOB, Aleksandra, KACJAN-MARŠIĆ, Nina. Biofortification of common buckwheat microgreens and seeds with different forms of selenium and iodine. Journal of the science of food and agriculture, ISSN 0022-5142. [Print ed.], 2019, vol. , iss. , str. v tisku, doi: 10.1002/jsfa.9669. [COBISS.SI-ID 9178489], [JCRSNIP] , kategorija: 1A1 (Z, A', A1/2); uvrstitev: SCI, IF=2,3. Poročilo o novi možnosti uporabe kalic ajde za prehrano, obogateno s selenom in jodom.
  • GOLOB, Aleksandra, STIBILJ, Vekoslava, KREFT, Ivan, VOGEL-MIKUŠ, Katarina, GABERŠČIK, Alenka, GERM, Mateja. Selenium treatment alters the effects of UV radiation on chemical and production parameters in hybrid buckwheat. Acta agriculturæ Scandinavica. Section B, Soil and plant science, ISSN 0906-4710, 2018, vol. 68, no. 1, str. 5-15, doi: 10.1080/09064710.2017.1349172. [COBISS.SI-ID 4366415], [JCRSNIPWoS do 22. 12. 2017: št. citatov (TC): 0, čistih citatov (CI): 0, čistih citatov na avtorja (CIAu): 0, Scopus do 29. 10. 2018: št. citatov (TC): 1, čistih citatov (CI): 1, IF=0,89. Rezultati gojenja hibridne ajde, tretirane z dodanjem selen, v razmerah klimatskih sprememb. Članek objavljen leta 2018 je že citiran (ni samocitat).
  • GORŠE, Sara, GOLOB, Aleksandra, GERM, Mateja. Effect of selenium, iodine and their combination on development of Tartary buckwheat sprouts = Vpliv selena in joda ter njune kombinacije na razvoj kalic tatarske ajde. Acta biologica slovenica : ABS, ISSN 1408-3671. [Tiskana izd.], 2018, vol. 61, št. 2, str. 85-92. [COBISS.SI-ID 4948815] . Objavljeni rezultati obogatitve kalic tatarske ajde s selenom in jodom ter ugotovitev vpliva na nekoliko zmanjšano vsebnost rutina.
  • LUKŠIČ, Lea, GERM, Mateja. Spremembe vsebnosti rutina in kvercetina v vzorcih tatarske ajde (Fagopyrum tataricum (L.) Gaertn.) od spravila pridelka do priprave kruha = Changes in the content of rutin and quercetin in samples of Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) from harvest to the preparation of bread. Folia biologica et geologica, ISSN 1855-7996. [Tiskana izd.], 2018, letn. 59, št. 1, str. 57-82, ilustr. http://www.sazu.si/uploads/files/57dfbe71e126b1a75cebe90f/FBG%2059-1%202018%20K.pdf, doi: 10.3986/fbg0039. [COBISS.SI-ID 4725327] , kategorija: 1C (Z). Ugotovili smo, da so predhodna hidrotermična (HT) obdelava zrnja, mlečno kislinska fermentacija ter priprava in peka vplivale na vsebnost skupnih flavonoidov ter vsebnost in pretvorbo rutina v kvercetin v vzorcih tatarske ajde in HT tatarske ajde. Vsebnost kvercetina se je v vzorcih med postopkom priprave in peke povečevala, med tem ko se je vsebnost rutina zmanjševala. Omenjeni postopki obdelave zrnja in vzorcev priprave in peke so vplivali tudi na spremembe skupne antioksidativne aktivnosti vzorcev tatarske ajde in HT tatarske ajde.
  • GOLOB, Aleksandra, STIBILJ, Vekoslava, NEČEMER, Marijan, KUMP, Peter, KREFT, Ivan, HOČEVAR, Anja, GABERŠČIK, Alenka, GERM, Mateja. Calcium oxalate druses affect leaf optical properties in selenium-treated Fagopyrum tataricum. Journal of photochemistry and photobiology. B, Biology, ISSN 1011-1344, 2018, vol. 180, str. 51-55, doi: 10.1016/j.jphotobiol.2018.01.018. [COBISS.SI-ID4621647], [JCRSNIPWoS, kategorija: 1A2 (Z, A1/2), IF=3,1. Poročilo o vsebnosti kalcijevega oksalata in silicija, relevantnih s stališča prehrane, v zelenih delih rastlin tatarske ajde tretiranih z raztopino selena.
  • GOLOB, Aleksandra, STIBILJ, Vekoslava, TURK, Judita, KREFT, Ivan, GERM, Mateja. Impact of UV radiation and selenium on two buckwheat species = Vpliv UV sevanja in tretiranja s Se na dve vrsti ajde. Acta biologica slovenica : ABS, ISSN 1408-3671. [Tiskana izd.], 2017, vol. 60, št. 2, str. 29-39. http://bijh-s.zrc-sazu.si/ABS/SI/ABS/Cont/60_2/Golob%20et%20al_ABS_2_2017_29-39.pdf. [COBISS.SI-ID 4556367] S seleno tretirani tatarska in hibridna ajda sta bili, kar se tiče vsebnosti Se v listih in zrnih, primerni za uporabo v prehrani ljudi in živali.
  • GERM, Mateja, LUTHAR, Zlata, TAVČAR BENKOVIĆ, Eva, ZHOU, Meiliang, GOLOB, Aleksandra, KACJAN-MARŠIĆ, Nina. Fagopyrin and rutin concentration in seeds of common buckwheat plants treated with Se and I = Vsebnost fagopirina in rutina v semenih navadne ajde tretirane s selenom in jodom. Folia biologica et geologica, ISSN 1855-7996. [Tiskana izd.], 2017, letn. 58, št. 2, str. 45-51, ilustr., doi: 10.3986/fbg0027. [COBISS.SI-ID 4469839] . Na koncentracijo rutina v zrnju pa so značilno vplivala tako posamična tretiranja z raztopinami obeh elementov(Se in J) kot tudi kombinirano tretiranje, na vsebnost fagopirina pa ni bil ugotovljen vpliv.
  • VOMBERGAR, Blanka, ŠKRABANJA, Vida, LUTHAR, Zlata, GERM, Mateja. Izhodišča za raziskave učinkov flavonoidov, taninov in skupnih beljakovin v frakcijah zrn navadne ajde (Fagopyrum esculentum Moench) in tatarske ajde (Fagopyrum tataricum Gaertn.) = Starting points for the study of the effects of flavonoids, tannins and crude proteins in grain fractions of common buckwheat (Fagopyrum esculentum Moench) and Tartary buckwheat (Fagopyrum tataricum Gaertn.). Folia biologica et geologica, ISSN 1855-7996. [Tiskana izd.], 2017, letn. 58, št. 2, str. 101-145, ilustr. http://dx.doi.org/10.3986/fbg0031, doi: 10.3986/fbg0031. [COBISS.SI-ID 4470863] . Pregledna kritična primerjava vsebnosti sekundarnih metabolitov v navadni in tatarski ajdi.
  • KREFT, Ivan, PONGRAC, Paula, ZHOU, Meiliang, VOGEL-MIKUŠ, Katarina, PELICON, Primož, VAVPETIČ, Primož, NEČEMER, Marijan, ELTEREN, Johannes Teun van, REGVAR, Marjana, LIKAR, Matevž, GERM, Mateja, GOLOB, Aleksandra, GABERŠČIK, Alenka, PRAVST, Igor, KUŠAR, Anita, VOMBERGAR, Blanka, ŠKRABANJA, Vida, KOCJAN AČKO, Darja, LUTHAR, Zlata. New insights into structures and composition of plant food materials. Journal of microbiology, biotechnology and food sciences, ISSN 1338-5178, 2017, vol. 7, no. 1, str. 57-61. http://www.jmbfs.org/jmbfs-fbp-08-kreft/?issue_id=4568&article_id=10, doi: 10.15414/jmbfs.2017.7.1.57-61. [COBISS.SI-ID 4407119]. Poročilo o metodah razporeditve metabolitov znotraj zrn ajde, ki so jih razvili v okviru tega projekta.
  • KREFT, Ivan, VOMBERGAR, Blanka, HORVAT, Marija, VORIH, Stanko. Buckwheat in the kitchen and for people. V: HABJANIČ, Oskar (ur.), ŠRIMPF VENDRAMIN, Katarina (ur.), BEVC VARL, Valentina (ur.). Debata o kuhinji = Kitchen debate = the collected volume of the symposium 19.-21. 10. 2017, (Zbirka Museoeurope, 4). Maribor: Pokrajinski muzej: = Regional Museum. 2017, str. 120-126.http://www.museoeurope.si/userfiles/MuseoEurope_2017.pdf. [COBISS.SI-ID 8877689]. Poročilo o razvoju različnih načinov uporabe ajde v prehrani.
  • GOLOB, Aleksandra, GADŽO, Drena, STIBILJ, Vekoslava, DJIKIĆ, Mirha, GAVRIĆ, Teofil, GERM, Mateja. Addition of Se affected concentration of Se in the second generation of Tartary buckwheat plants = Dodatek selena je vplival na koncentracijo Se v potomkah s Se obravnavanih rastlin. Folia biologica et geologica, ISSN 1855-7996. [Tiskana izd.], 2016, letn. 57, št. 1, str. 87-92, ilustr. [COBISS.SI-ID 4089167] . Ugotovljen je epigenetski vpliv na vsebnost selena v naslednji generaciji ajde.
  • KREFT, Ivan, PONGRAC, Paula, ZHOU, Meiliang, VOGEL-MIKUŠ, Katarina, PELICON, Primož, VAVPETIČ, Primož, NEČEMER, Marijan, ELTEREN, Johannes Teun van, REGVAR, Marjana, LIKAR, Matevž, GERM, Mateja, GOLOB, Aleksandra, GABERŠČIK, Alenka, PRAVST, Igor, KUŠAR, Anita, VOMBERGAR, Blanka, ŠKRABANJA, Vida, KOCJAN AČKO, Darja, LUTHAR, Zlata. New insights into structures and composition of plan food materials. V: Book of abstracts and posters, the 12th International Scientific Conference [on] Biotechnology and Quality of Raw Materials and Foodstuffs, Nitra, Slovakia, May 16-18, 2017. Nitra: Slovak University of Agriculture. 2017, str. [1]. [COBISS.SI-ID 8744057] . Poročilo o rezultatih raziskovanja vsebnosti metaboloitov v zrnju ajde.
  • GOLOB, Aleksandra, GADŽO, Drena, STIBILJ, Vekoslava, DJIKIĆ, Mirha, GAVRIĆ, Teofil, KREFT, Ivan, GERM, Mateja. Sulphur interferes with selenium accumulation in Tartary buckwheat plants. Plant physiology and biochemistry, ISSN 0981-9428. [Print ed.], 2016, vol.108, str. 32-36, doi: 10.1016/j.plaphy.2016.07.001. [COBISS.SI-ID 3937359], [JCRSNIPWoS do 13. 1. 2019: št. citatov (TC): 5, čistih citatov (CI): 5, IF=2,7. Ugotovljena in prvič objavljena je interference žvepla s selenom v rastlinah tatarske ajde. Od objave je članek dosegel že 5 čistih citatov. kategorija: 1A1 (Z, A'.).
  • LUKŠIČ, Lea, ÁRVAY, Július, VOLLMANNOVÁ, Alena, TÓTH, Tomáš, ŠKRABANJA, Vida, TRČEK, Janja, GERM, Mateja, KREFT, Ivan. Hydrothermal treatment of Tartary buckwheat grain hinders the transformation of rutin to quercetin. Journal of cereal science, ISSN 0733-5210, 2016, vol. 72, str. 131-134, doi: 10.1016/j.jcs.2016.10.009. [COBISS.SI-ID 4088911], [JCRSNIPWoS do 27. 8. 2018: št. citatov (TC): 1, čistih citatov (CI): 1 (Že dosežen citat, brez avtocitatov). Preprečevanje transformacije rutina v kvercetin pri tatarski ajdi s temperature pri predelavi.
  • DZIEDZIC, Krzysztof, GÓRECKA, Danuta, SZWENGIEL, Artur, OLEJNIK, Anna, RYCHLIK, Joanna, KREFT, Ivan, DROŻDŻYŃSKA, Agnieszka, WALKOWIAK, Jarosław. The cytotoxic effect of artificially digested buckwheat products on HT-29 colon cancer cells. Journal of cereal science, ISSN 0733-5210, 2018, vol. 83, str. 68-73, doi: 10.1016/j.jcs.2018.07.020. [COBISS.SI-ID 9013881], [JCRSNIPWoS do 10. 2. 2019: št. citatov (TC): 1, čistih citatov (CI): 1 (Že dosežen citat, brez avtocitatov), IF=2,3. Ugotovljeno je da izdelek iz ajde zavira razvoj rakastih celic debelega črevesa.
  • DZIEDZIC, Krzysztof, GÓRECKA, Danuta, SZWENGIEL, Artur, SULEWSKA, Hanna, KREFT, Ivan, GUJSKA, Elżbieta, WALKOWIAK, Jarosław. The content of dietary fibre and polyphenols in morphological parts of buckwheat (Fagopyrum tataricum). Plant foods for human nutrition, ISSN 0921-9668, 2018, vol. 73, iss. 1, str. 82-88, ilustr., doi: 10.1007/s11130-018-0659-0. [COBISS.SI-ID8938105], [JCRSNIPWoS do 10. 2. 2019: št. citatov (TC): 1, čistih citatov (CI): 1, (Že dosežen citat, brez avtocitatov). IF=2,4. Rastline tatarske ajde smo razdelili na socvetja, liste, stable in korenine. Z uporabo RP–UHPLC–ESI-MS equipment (reversed-phase ultra-high-performance liquid chromatography electrospray ionisation mass spectrometry) smo raziskali vsebnosti klorogene kisline, fagopirina, kempferola, procianidina B2, kvercetina in njegovega 3-D-galaktozida, rutina in viteksina, ki jih je bilo več v alkoholnem ekstraktu v primerjavi z vodnim.

logo nutris

Nutrition Institute
Koprska ulica 98
1000 Ljubljana

How to find us

+386 5 9068 870

+386 1 300 79 81



Other information:

IBAN: SI56 340001012501108
Bank: Sparkasse d.d.
VAT ID: SI50465856
Reg. No.: 3609081000


Subscribe to newsletter
(in Slovenian language only)


+386 5 9068 870

+386 1 300 79 81


Follow us


Subscribe to newsletter
(in Slovenian language only)


Nutrition institute is engaged in research and education in the field of nutrition and advising the food industry in the formulation and labeling of foods. In the scope of the institute, research group Healthy Nutrition is established, which performs research on food and nutrition.