CERERE aims at sustaining and promoting innovative approaches emerging in Europe from a multitude of practices adopted to introduce and manage agrobiodiversity in cereal production. These innovations are rooted in local traditions, knowledge and food culture.

CEreal REnaissance in Rural Europe: embedding diversity in organic and low input food systems

COLLECTED SOLUTIONS ON BAKING

Booklet #3

Camille Vindras-Fouillet, Estelle Serpolay-Besson,

ITAB

English

Breeding of wheat populations touches on agricultural, sensory and nutritional considerations, yet it is limited by technical obstacles. This manual describes processes for enhancing and disseminating knowledge to the end of improving cultivation and processing practices.

Authors

IndexIndex pag. 3

Features of wheat populations pag.4

Characteristics of sourdough bread pag. 6

Technical obstacles to their processing pag. 8

Strategies that can be pursued to develop production pag.10 chains for wheat populations

References pag.17

Consortium pag.19

Camille Vindras-Fouillet, Estelle Serpolay-Besson,ITAB

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Features of wheat populations The genetic structure of the varieties can be homogene-ous with no intra-varietal variability (pure lines, F1 hybrids, clones) or heterogeneous (blends, populations). These diversified genetic structures are suited to organic agri-culture (OA), as they favour dynamic adaptation to local conditions and to changes in climate [1]. As is emphasized by the synonym “local varieties”, breeding of these varie-ties involves elements of both local heritage and econom-ics (adaptation of the varieties to the production system, and seed independence) [2]. They reveal agronomic perfor-mance levels comparable to those of modern varieties in OA contexts [3]. The increase in genetic diversity through cultivation of populations can therefore improve the sta-bility of an agro-biological system[4, 5]. Complementarity between genotypes favours the stability of the ecosystem, as from one generation to the next plants progressively adapt to fluctuating environmental conditions [6]. Their ge-netic diversity further has the potential for improving nu-trition and aroma on the basis of these criteria [3, 7]. A doctoral thesis that examined 723 varieties of organically cultivated soft wheat showed the existing variability in the mineral content of the examined varieties [8]. Old varieties are those that show the highest percentages of Zn and K, and to a lesser extent of B, Cu, Mg, Ca, P and S. A significant evolution of nutritional composition was observed from old to modern varieties, suggesting the potential of the former [1]. Various studies demonstrate that changes in the

nutritional composition of the wheat grain is in part genetically controlled [3, 9]. Researchers have noted links between nutritional composition and sensory qualities. A recent publication focuses on sensory quality and suggests the potential of the organoleptic properties of wheat populations [7].

The results show a difference between local and old populations, characterized by notes of porridge, oats and bulgur, and modern varieties, described as having aromas of wild rice, cooked malt, bitters, cocoa and vanilla.

Alkaline metals such as potassium and alkaline earth metals such as magnesium may contribute to the taste of wheat bread. The colour of wheat is linked to the percentage of carotenoids and is a factor with a potential effect on bread quality [10, 11]. Lutein, the main carotenoid contained in the wheat grain, may influence bread aromas by limiting the development of hexanal, a compound at the base of unpleasant sensory characteristics [12]

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Characteristics of sourdough bread The use of these wheat varieties goes hand in hand with arti-sanal processing. Indeed, because their tenacity has not been selected, their doughs tear when subjected to the action of the mechanical arms used in commercial processing. Sour-dough is the most widespread form of processing to make bread from these wheat varieties.The use of sourdough for bread making offers several advan-tages, such as its suitability for artisanal procedures, a greater presence of nutritional substances in the bread, and a variety of tastes of bread, thanks to the diversity of natural yeasts, of local growing conditions, of wheat varieties and of bread making systems.Bread making with sourdough allows for an increased con-tent of biological minerals in bread. This means slower di-gestion of starch, which triggers a lower glycaemic response. More generally, the use of sourdough produces breads which are more easily digested in terms of fibres, which contain re-duced amounts of phytic acid, and which produce prebiotics on the part of lactic acid bacteria that free extracellular poly-saccharides [13]. Sourdough bread shows great variety in organoleptic terms, thanks to the diversity of natural yeasts (contrary to stand-ardized commercial yeasts), of production processes (both with regard to cultivation and bread making), of the wheat populations used and of local growing conditions [14]. Yeasts and bacteria present in sourdough produce breads with characteristic aromas, which vary according to the microbial composition of the various types of sourdough [15]. In addition, bread made with sourdough has a good shelf life.La culture de populations de blé est limitée par l’organisation de la filière pain.

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Breeding of wheat popu-lations is constrained by the organization of the bread production chain. Indeed, the variability of their quantity is not suit-ed to long production chains. Certain integrated production chains, such as those of farmer-bread makers, do not require the same characteris-tics as commercial bread making. Farmer-bread makers show interest in these populations, which in addition to agronomic features suited to OA pos-sess significant nutrition-al and sensory potential. Wheat bread is obtained by processing soft wheat grains into flour, which is blended and then com-bined with water, salt and a leavening agent – yeast or sourdough. As with any other natural prod-

Technical obstacles to their processing

uct, wheat undergoes dif-ferent types of variations: the variety, environment and bread making sys-tem, together with the ripening time (the time of wheat processing be-tween harvest and mill-ing) or the type of milling are also variables which have an impact on each processing sequence in terms of specific nutri-tional, technological and sensory characteristics. Such variations are above all significant with regard to the quality and quanti-ty of proteins [16]. To opti-mize bread making from a particular type of flour, the processor must be able to foresee the suit-ability of the flour’s char-acteristics for bread mak-ing, adapting the recipe accordingly. Millers have at their disposal a series of analytical methods to measure these variables,

such that they can deter-mine the suitability of a flour to bread making. In France, another factor places limits on adopting these practices: legisla-tion there restricts the ex-change and sale of these varieties. Nonetheless, the use of varieties which are not catalogued is per-mitted in experimenta-tion and within integrat-ed production chains.Modern selection prac-tices have produced in-creased yields, which are especially made possible by the introduction of the dwarf gene. Many re-sistances to disease have been introduced (such as those against eyespot, powdery mildew and rust) to reduce the use of fungicides [17]. The suitabil-ity of flours for bread mak-ing, finally, which much depends on the quality and quantity of the glu-ten, has been increased significantly and adapted to the methods of com-mercial bread production. Nonetheless, over the last

few decades a negative correlation has emerged between the percentage of protein and yield, ren-dering impossible their simultaneous improve-ment. Wheat populations, therefore, have not been selected on the basis of their gluten tenacity. As a result, they are not suited to mechanized commer-cial production chains but can only be made into bread through sour-dough leavening, in par-ticular by applying a slow fermentation protocol. Nonetheless, this meth-od of bread making is not widespread in artisanal processing. Because there exists a great diversity of popula-tions and because each population has particular qualities, it is necessary to acquire greater knowl-edge of their agronomic and technological char-acteristics to favour culti-vation of these varieties.

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Strategies that can be pursued to develop production chains for wheat populations

IMPROVEMENT OF KNOWLEDGE

To improve knowledge about these populations, participatory selection must be developed by combining the knowl-edge and experience of researchers and farm-ers in order to respond to their specific expectations. Knowledge must there-fore be spread to optimize practices.A first step consists in cre-ating a collection of pop-ulations to observe their agronomic behaviour and their suitability to specif-ic environments. Micro parcels limit research on these collections to their

agronomic characteristics. To test the suitability of these varieties for bread making, it is necessary to multiply the selected populations in the first stage in order to breed them on larger parcels. Af-ter testing the suitability of these populations (pure and/or blended) for bread making, often a “blend for bread making” is cre-ated on the basis of agro-nomic, technological and sensory results [18]. In order to predict suita-bility for bread making, an experimental collective has created a pre-test to assess and compare the strength of flours used in a blend and to deter-

mine their proportions [18]. Before using the flours for the first time, a comparative test of their states is carried out through autolysis: the same quantities of flour and water are mixed in containers of equal size, and the mixes are left to rest for several hours. The extensibility of each sample is then evaluated by stretching each mix of flour and water and measuring how long it takes for the dough to tear.An important aspect of the study of the varieties with re-gard to the final quantity of bread concerns the bread making protocol. Indeed, standard methods call for inten-sive processing and fixed bread-making parameters (hy-dration percentage and leavening time). These methods are not suited to either artisanal practices or local varieties. Because the technological behaviour of flours varies from one variety to another (hydration percentage, enzymatic activity, etc.), such practices produce a distinction between breads based on defects of the bread making process and not on the expression of the grains in the bread. To compare breads made from different varieties, rather than basing evaluations on hydration percentages, a col-lective in Brittany has suggested assessing dough con-sistency instead of a pre-established leavening time, and has proposed that the optimal moment for baking bread is when it reaches the peak of its rising. A grid based on BIPEA tests (the usual evaluation method) has been sim-plified, and the recipe has been adapted to sourdough breads produced with farmer varieties [16]. During the tests and the work of the collectives, bread making pro-tocols were proposed with the aim of optimizing sensory and nutritional quality [18]. The use of young, endogenous sourdough (obtained with the tested flour) of semi-whole wheat flour optimizes the taste of the bread variety. Slight insemination combined with rising for 18 hours at 20°C favours bread digestibility and mineral availability.

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Figure 1: C

omparison of slices of breads produced from

pure lines (MM

) and populations (MA

) cultivated in four environments

(GS, LA

, FM and LM

) and with four types of sourdough (M

P, PV, HS and LM

)

The research context limits the application of sensory methodologies, which involve training a panel (availa-bility of farmers, baking in a baker’s oven). The Napping method, based on a representation of sensory distanc-es, was often used in research for a doctoral thesis [18] and has been continually adapted according to results. This test, which has been authenticated by perception metrologists [19], consists in measuring sensory distanc-es between breads tasted by each taster. Comparison of these perceptions highlights the perceived differences of the majority of tasters. This allows researchers to evaluate the relative influence of technical factors (variety, environ-ment, etc.) on the final quality of the product [20, 21]. It is also possible to take advantage of the skills of such professionals as bread makers, who have a more diversi-fied taste standard than most people, in order to establish a terminology of tastes suitable for each species/variety and to be able to more accurately define a product’s aro-mas. Later, this lexicon can be organized in the form of a taste wheel to facilitate the characterization of products.

To the end of improving and sharing knowledge, it is useful to develop a database that brings together eval-uations made by farmers in their respective fields of ex-pertise. This common characterization of wheat varieties favours the identification of those populations which best adapt to various agronomic conditions; to this evaluation is added gene-environment interaction (GxE) to express final quality. The aim here is to characterize populations in terms of agronomic performance, but also with regard to their suitability for bread making. In order to be able to compare these data and draw conclusions, observation

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Figure 2:Wheel of bread aromas. Source: Groupe Minoterie SA (Copyright ZHAW 2008)

methods must be uni-form. This requires the use of common terminology and the same evaluation scale. Carrying out collective bread making tests – ones which compare variety-en-vironment pairings and use uniform bread mak-ing parameters – favours this sharing of knowledge. By making possible the collective characterization of populations, this initi-ative has the final goal of facilitating the selection of populations to be test-ed based on objective and relevant criteria.

DISSEMINATING KNOWLEDGE TO OPTIMIZE PRACTICES

Selection and manage-ment of wheat popula-tions must allow farm-ers to obtain populations suited to their local con-ditions, while at the same time preserving a capacity for adaptation by means

of maintaining genetic diversity. Selection at the farm level allows each pro-ducer to find populations suited to his/her condi-tions, with good results in terms of taste. Together with RSP, GAB 65 has developed a strategy for the dynamic management of diversi-ty to maintain population diversity at the farm level. Thanks to genetic renew-al on the order of several percentage points each year, this method allows the adaptation capacities of wheat populations to be maintained. To maintain the genetic diversity of populations, farmers can create seed blends. For example, at meetings of farmers, each participant might bring 5 kg of seeds of his/her population, which will be mixed with those of the populations of other farms. At the end, each farmer leaves with 5 kg of seeds from this new blend to integrate them into his/her population. Visits to

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the farmer’s parcels make possible a comparison of the populations of the different farms. Regarding preserva-tion of the varieties, farmers must be careful not to mix lots with seeds of different varieties or species, as such mixed seeds will appear on the parcels of all participating farmers. By this means, technical obstacles that limit the develop-ment of cultivation of wheat populations can be eliminat-ed, as the organization of participatory research will both improve and disseminate knowledge. We still lack data on the positive externalities of these production chains, which are currently being collected.

references[1] Roussel, V., Leisova, L., Exbrayat, F., Stehno, Z., Balfourier, F., 2005. SSR allelic diversity changes in480 European bread wheat varieites released from 1840 to 2000. Theor. Appl. Genet. 162–170.

[2] Bocci, R., Chable, V., 2007. Semences paysannes en Europe: enjeux et perspec-tives. Cah. Agric. 17, 216–221.

[3] Di Silvestro, R., Marotti, I., Bosi, S., Bregola, V., Carretero, A.S., Sedej, I., Mandic, A., Sakac, M., Benedettelli, S., Dinelli, G., 2012. Health-promoting phytochemicals of Italian common wheat varieties grown under low-input agricultural manage-ment. J. Sci. Food Agric. 92, 2800–2810. doi:10.1002/jsfa.5590

[4] De Vallavieille-Pope, C., Belhaj Fraj, M., Mille, B., Meynard, J.-M., 2006. Les asso-ciations de variétés : accroître la biodiversité pour mieux maîtriser les maladies. Doss. Environ. INRA Quelles Variétés Semen. Pour Agric. Paysannes Durables 101–109.

[5] Döring, T., Wolfe, M., 2008. Stabilising wheat yields: can genetic diversity in-crease reliability of wheat performance. Arable Group 10–11.[6] Jackson, L.F., Kahler, A.L., Webster, R.K., Allard, R.W., 1978. Conservation of scald resistance in barley composite cross populations. Phytopathology 68, 645–650.

[7] Starr, G., Bredie, W.L.P., Hansen, A.S., 2013. Sensory profiles of cooked grains from wheat species and varieties. J. Cereal Sci. 295–303.

[8] Hussain, A., 2012. Quality of organically produced wheat from diverse origin. Swedish University of Agricultural Sciences, Alnarp.

[9] Leenhardt, F., Lyan, B., Rock, E., Boussard, A., Potus, J., Chanliaud, E., Remesy, C., 2006. Genetic variability of carotenoid concentration, and lipoxygenase and peroxidase activities among cultivated wheat species and bread wheat varieties. Eur. J. Agron. 25, 170–176. doi:10.1016/j.eja.2006.04.010Leenhardt et al., 2006).

[10] Li, L., Shewry, P.R., Ward, J.L., 2008. Phenolic Acids in Wheat Varieties in the HEALTHGRAIN Diversity Screen. J. Agric. Food Chem. 56, 9732–9739. doi:10.1021/jf801069s

[11] Liu, Q., Qiu, Y., Beta, T., 2010. Comparison of antioxidant activities of different coloured wheat grains and analysis of phenolic compounds. J. Agric. Food Chem. 9235–9241.

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-cerere-

consortiumParticipating organisation Country

University of Reading UK

Università degli Studi di Firenze Italy

Rete Semi Rurali Italy

Réseau Semences Paysannes France

Institut National de la Recherche Agronomique France

Helsingin Yliopisto Finland

TEAGASC - Agriculture and Food Development Authority Ireland

Asociación Red Andaluza de Semillas Cultivando Biodiversi-dad Spain

formicablu S.r.l. Italy

Progressive Farming Trust LTD LBG UK

SEGES PS Denmark

Institut Technique de l’Agriculture Biologique France

Debreceni Egyetem Hungary

[12] Institut National de la Boulangerie Pâtisserie, 2003. Supplément technique INBP n°83-Le goût du pain.

[13] Behera, S. et Ray, R., 2015. « Sourdough bread; In : Bread: its Fortification for Nu-trition and Health » (Cristina M. Russell, ed), CRC press, USA. 53-67. [ https://www.researchgate.net/publication/286921816_Sourdough_bread_In_Bread_its_Fortifi-cation_for_Nutrition_and_Health_Cristina_M_Russell_ed_CRC_press_USA ]

[14] LCD, 2017. « Compte-rendu de la rencontre européenne Let’s Cultivate Diversity de juin 2017.  » [https://be2017.cultivatediversity.org/index.php/fr/compte-rendu-de-la-rencontre/] (Le compte-rendu sera publié prochainement)

[15] Ramsayer J., Sicard D., 2015. « Explorer et conserver la diversité de la flore des levains, un potentiel  en boulangerie.  » Innovations Agronomiques 44, 45-54. [https://www6.inra.fr/bakery/Publications/Publications-en-francais]

[16] PaysBlé, Développement d’un réseau régional pour expérimenter, maintenir et promouvoir la diversité cultivée des blés de terroir bretons en agriculture bi-ologique, Rapport final, octobre 2012

[17] Doré, C., Varoquaux, F., 2006. Histoire et amélioration de 50 plantes cultivées, QUAE. ed, Savoir faire. INRA Editions.Doré and Varoquaux, 2006)

[18] Vindras-Fouillet, C. Mémoire de doctorat, Ecole Doctorale « VIE AGRO SANTE », Décembre 2014. Evaluation de la qualité sensorielle de produits pour la sélection participative en agriculture biologique : cas du blé et du brocoli.

[19] Faye, P., Brémaud, D., Durand Daubin, M., Courcoux, P., Giboreau, A., Nicod, H. 2004. “Perceptive free sorting and verbalization tasks with naïve subject: an al-ternative to descriptive mappings”, Food Quality and Preference (15), pp.781-791

[20] Vindras-Fouillet, C., Ranke, O., Anglade, J.P, Tau^pier-Letage, B., Chable, V., Gol-dringer, I. 2014. “Sensory analyses and nutritional qualities of hand-made breads with organic grown wheat bread populations”, in Food and Nutrition science (5), pp. 1860-1874. http://dx.doi.org/10.4236/fns.2014.519199

[21] Vindras-Fouillet, C., Rouellat, V., Hyacinthe, A., Chable, V., 2016. “Empirical knowl-edge in Participatory research: integration of the sensory quality of bread in the plant breeding process of Wheat in France”, in Universal Journal of Agricultural Research (4), pp. 5-14. Doi: 10.13189/ujar.2016.040102

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l Cerere2020 Cerere | Project info@cerere2020.eu | www.cerere2020.eu

“CERERE is a thematic network that brings scientists and practitioners together. Its aims are to raise awareness about the value of good food, to identify cereal supply chains which use low inputs, to empower farmers

and those actors who work with alternative food systems”

- CERERE consortium, Kick Off Meeting, University of Reading, November 2016

This project received funding from the European Union’s Horizon 2020 Rese-arch and Innovation program under Grant Agreement n° 727848.

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