The wheat grain is a heterogeneous structure with bio-active compounds unevenly distributed within its different parts. The bioactive compounds (fibres, micronutrients and phytochemicals) are mostly concentrated in the grain outer layers, each having its own compositional profile.
Therefore levels of bioactive compounds in whole meal flour are at least two times higher than those in white flour. However, some of the bioactive compounds have a low bio-accessibility in peripheral layers as they are trapped in strong cell wall structures which resist conventional milling. They can also be localized close to undesirable contaminants such as microbes, mycotoxins, pesticide residues, heavy metals. Therefore novel technologies have been developed for the transformation of the grains to better exploit their nutritional potential and to ensure food safety requirements.
In order to develop new dry processing techniques, new tools based on new insights in grain tissue composition, structure and properties have been obtained. Biochemical markers of the different grain tissues (pericarp, intermediate layers, aleurone layers, germ) have been identified and allow to determine the tissue composition of the technological fractions and deduce the behaviour of the different grain parts upon fractionation operations. More rapid methods for fractionation monitoring using spectral signature of tissues are on the way. New mechanical devices coupled with microscopy and microspectroscopy have been developed to determine the local properties of tissues and of their interfaces to help the development of fractionation with improved resolution. Especially, the effects of temperature, water content and enzymatic pre-treatments have been investigated.
A way to enrich cereal products with bioactive compounds is to manufacture flours with high levels of selected parts of the outer layers. To remove the very outermost layers, partial debranning of grains in using friction (peeling) or abrasion (pearling), was combined with milling (grinding and sieving) to produce flours with tailored tissue composition and thus controlled in content of bioactive compounds, as monitored by the marker methodology. Flours made from peeled grains, peeled and pearled grains and grains with removed outermost layer and crease parts exhibited high contents of bioactive compounds and improved nutritional effects as compared to common flours.
Another way of exploiting cereal potential is to use the miller's bran, a by-product of the milling industry, as a source of healthy ingredients. Careful limited grinding and sieving of the bran allowed to prepare a concentrate of aleurone cells and aleurone layer, where most of the bioactive compounds of the grain are located. Further purification by electrostatic classification yielded practically pure aleurone cells that exhibited excellent nutritional properties.
Another approach used ultrafine grinding of the bran in ambient or cryogenic conditions, to provoke a full dissociation of the material at a sub-cellular level. This resulted in an increase in bioactive compounds bioaccessibility. Classification of the fine particles in using a electrostatic separator made it possible to prepare fractions of very contrasted compositions in starting from bran. One of these ingredients, concentrated in fine aleurone particles, showed a good accessibility of anti-oxidants and mineral compared to bran and untreated aleurone. These technologies have been experimented at large-scale by industrial partners, to determine their feasibility and economics.
The work was conducted by INRA, in close collaboration with difent partners in charge of analyses (VTT, KU Leuven, University of Helsinki, University of Uppsala, Puratos, TNO), development of analytical equipment (Branscan) and industrial demonstration and cost evaluation (Barilla, Buhler, SD-Tech).
The EU Integrated Project HEALTHGRAIN: The HEALTHGRAIN project has substantially strengthened the scientific basis for a new generation of cereal based products with enhanced health benefits. The project also has formed a network of research organizations, industries and organizations communicating to consumers that will continue as the HEALTHGRAIN Forum. It has been coordinated by Academy Professor Kaisa Poutanen from VTT Technical Research Centre of Finland. Results of the project will be presented in the HEALTHGRAIN Conference on May 5-7 in Lund, Sweden: www.healthgrain.org
INRA: Ranked the number one agricultural institute in Europe and number two in the world, INRA carries out mission-oriented research for high-quality and healthy foods, competitive and sustainable agriculture and a preserved and valorised environment.
Barilla: Barilla was founded in Parma back in 1877, as a small shop of bread and pasta, opened by Pietro Barilla. For over 130 years it has been guided by the entrepreneurial experience of a family that, with the advent of the siblings Guido, Luca, Paolo and Emanuela, has been at the helm for four generations. Today Barilla Group produces and sells, at international level, pasta, pasta sauces and bakery products. Current organizational structure is based on Barilla G&R. Fratelli, Harry's and Lieken, together with their subsidiaries. Nowadays, Barilla operates directly in more than 20 countries and exports its products to over 100 countries. It owns 54 production facilities in 10 countries and has more than 15,000 employees.
Buhler: Buhler is market leader in grain processing technologies and speciality milling with a strong focus on innovative processes for healthier grain fractions and ingredients for their customers in the grain processing industry world-wide. Buhler is present in more than 140 countries.
SD-Tech: SDTech is an industrial company specialising in the custom micronization and analysis of ultra-fine powders. SDTech delivers Process Expert services to various industries. SDTech offers its expertise for customized services in various areas such as custom milling (dry and wet processes), sieving, mixing and powder analysis.
Barron, C., Surget, A. and Rouau, X. Relative amounts of tissues in mature wheat (Triticum aestivum L.) grain and their carbohydrate and phenolic acid composition. Journal of Cereal Science 2007, 45, 88-96.
Hemery, Y.; Rouau, X.; Lullien-Pellerin, V.; Barron, C.; Abecassis, J. Dry processes to develop wheat fractions and products with enhanced nutritional quality. Journal of Cereal Science 2007, 46, 327-347.
Hemery Y.M., Lullien-Pellerin V., Rouau X.,Abécassis J., Samson M.F., Åman P., von Reding W., Spoerndli C.and Barron C. Biochemical markers: efficient tools for the assessment of wheat grain tissue proportions in milling fractions. Journal of Cereal Science. 2009, 49, 45-64.
Further information:INRA, UMR Agropolymer Engineering and Emerging Technologies, Montpellier, France
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy