Naked Barley - a rediscovered source for functional foods!

Cereal-based foods represent the bulk of all foods consumed and their contribution to human nutrition and health should be considered cumulative, immediate and significant. The concept of "functional foods" has become popular in recent years. Certain constituents of cereals are not considered as essential but may promote beneficial physiological effects (beyond vitamins and minerals). Naked (hulless) barley, which is the subject of this project, possesses interesting technological properties and is due to its high contents on dietary fibre (beta-glucan) and secondary plant metabolites (polyphenols and carotenoids) recognised as valuable nutritional source. Only recently, cereal science has started to look into the potential of secondary plant metabolites as natural antioxidants. Reports on their content, as well as technological properties during food processing are scarce. Furthermore, most of the available data have been collected in the USA or Canada and do not necessarily reflect the contents in European varieties. Besides, their contents have been underestimated and full characterisation of the phytochemicals has been deficient. Therefore, we discern a need for this proposed research. Our approach in this project is to combine selection (breeding programme), processing and analytical expertise in an innovative way within 3 work packages. Based on an existing collection of genetic resources of naked barley we will select genotypes rich in either dietary fibre (beta-glucan) and/or secondary plant metabolites. Within the technology work package the project will emphasise the utilisation of such raw materials and will determine changes in these health beneficial components during processing. With new evidence about the antioxidant capacity of cereal-based foods, the project will contribute in an important way to consumer health and quality of life. The project is highly multi-disciplinary, with competent scientists in the fields of agriculture, technology, analytics and nutrition. The variation of Austrian-grown barley germplasm from conventional cross breeding will be explored with respect to known nutritionally-important and potentially health-relevant constituents. Long term, enhanced genotypes can be added to the gene-pool database, with the advantage of adaptation to the environmental growing conditions. This will positively affect the diversity and sustainability in Austrian agriculture. The food industry is generally confronted with the increasing globalisation and customisation, resulting in dwindling of local produce and typical Austrian food. After successful termination of this project the way for food with added nutritional benefit to the consumers is smoothed.

Barley is an excellent source of many valuable nutrients, such as soluble and insoluble dietary fibres, minerals and phenolic compounds and is therefore a desirable ingredient in baked products, although the poor baking qualities have hampered a more pronounced use in human nutrition. Based on an existing collection of genetic resources of naked barley the approach of this project was to select naked (hull-less, hulless) genotypes. Criteria were high yields in dietary fibres (especially the soluble fraction of beta-glucans) as well as secondary plant metabolites. The use of this rarely used barley varieties in the food production demands to question the applicability of standard methods that are commonly tailored to wheat. The verification or modification of these standard methods made a reliable description of the baking qualities of naked barley flours possible. With that, further emphasis was brought to the technological use of naked barley for cereal-based food products. The highest nutritional value of naked barley is now seen in the high content of beta-glucans. The European Food Safety Authority (EFSA) identified that a regular consumption of beta-glucans contributes to maintenance of normal blood cholesterol concentrations. Additionally, beta-glucans are as well suggested to positively influence the blood glucose level. This discussion was used as an opportunity to drive further applied research in the field of food technology and nutritional science. Bread is one of the most important cereal products which is daily consumed in higher amounts. For this reason, the effect of beta-glucans and insoluble dietary fibres of different naked barley bread formulations on the change of blood glucose levels within time was studied. Above that, changes in respect to the content of secondary plant metabolites during processing (baking) were investigated and documented.