The interest for barley in human nutrition increased primarily thanks to evidences that consumption of barley reduces blood cholesterol and glycemic index, and promotes weight loss by increasing satiety. Notwithstanding, barley is marginally exploited by the baking industry due to its deteriorating effect on bread quality. The use of sourdough may improve the quality of barley bread, hence, sourdoughs produced with selected lactic acid bacteria and yeasts were used for barley-flour-based bread-making. Bread-making trials were carried out in a local bakery which used different percentages of barley-, wheat-flours and sourdoughs. The results showed that the barley sourdoughs were suitable to obtain barley bread with enhanced nutritional value and high degree of liking; the results were confirmed by the successful exploitation of barley flour in local bakeries which started to produce and sell barley bread called Pandorzo and a preparation for home-made barley bread called Barley Mix.
Università Politecnica delle Marche, Ancona - ItalyLead applicant
formazione e ricerca
Molino Stacchiotti s.r.l. - ItalyInitiative partner
School of Food and Nutritional Sciences, University College Cork - IrelandInitiative partner
DeFENS - ItalyInitiative partner
Prometeo - ItalyInitiative partner
ASSAM - ItalyInitiative partner
La Casa del Pane - ItalyInitiative partner
UNIQUE NUTRITIONAL PROPERTIES OF BARLEY BREAD
The main advantage of using barley flour in food processing lies in its unique nutritional properties, in particular, the high content in b-glucans. In this project barley flour was used to partly or fully substitute wheat flour in sourdough bread-making in order to raise the soluble fiber content of barley breads. The results obtained demonstrated the suitability of barley flour for the manufacture of bread with enhanced nutritional value and overall consumer acceptance. Barley breads had overall acceptability scores comparable to those of wheat bread. This latter finding, combined with the increased b-glucan content of barley bread, encourages research directed toward a further optimization of sourdough fermentation and breadmaking with barley flour, to obtain barley bread with a further improvement in terms of appeal for consumers.
Barley originated in Ethiopia and Southeast Asia, where it has been cultivated for more than 10,000 years. It was used by ancient civilizations (e.g. Egyptians, Greeks, Romans) as food for humans and animals, as well as for the production of alcoholic beverages. Today, barley is mainly used in animal feed and as grain for malting and brewing; further applications include the production of coffee substitutes and non-alcoholic drinks, as well as the preparation of soups and stews in eastern Europe. This high fibre cereal is only marginally exploited by the baking industry which could advantage by the development of barley-based breads, In fact, the fresh bakery segment is a mature market showing to be dynamic and in the growth phase.
The health claim associated to barley beta-glucans states that at least 3 g of barley beta-glucans should be consumed per day in order to obtain a decrease in total and LDL-cholesterol concentration in both normo- and hypercholesterolaemic subjects. Therefore about 100 g of barley bread (2.3 g/100 g of beta-glucans) consumed per day should be sufficient in order to obtain the claimed effect, while 100 g of a bread produced with a mixture of 50% barley flour and 50% wheat flour (1.052 g/100 g beta-glucans) consumed per day could partially contribute to the daily dietary intake of beta-glucans. The results of the project demonstrated the efficacy of the use of sourdough in improving mineral bioavailability in bread, by increasing phytic acid hydrolysis.
There are significant markets for health and wellness-oriented bakery products, with high- fibre bread being the most popular, furthermore, there is a continuous increasing demand for a greater variety of bread with ethnic breads becoming more popular as well as wholemeal breads with barley, oats, bran, seeds, etc. The present project contributed towards addressing a number of societal objectives. Barley bread produced through sourdough fermentation already meets all ages consumer demand for healthy foods, since it assures a reduction in the glycaemic index, and an enhancement of mineral bioavailability; with this initiative a novel product has been launched on the local market. Barley bread produced by La Casa del Pane has been analysed by Public Scientific Body which attested the antioxidant amount and the lowering effect on postprandial blood glucose.
The initiative started with the selection of lactic acid bacteria and yeasts isolated from local sourdoughs performed by the researchers of Università Politecnica delle Marche in cooperatione with ASSAM. The SMEs Prometeo and Molino Stacchiotti provided barley and wheat flours for built-up the wheat and barley sourdoughs added with the selected microbial strains used in association. La Casa del Pane (SME) performed the barley-based bread making trials and bread sensory analyses; while DeFENS performed the rheological and technological characterisation of the doughs and breads, respectively. Nutritional properties of flours, doughs and breads were carried out by School of Food and Nutritional Sciences, University College Cork. Barley bread is still produced by La Casa del Pane.
Initial barley bread volumes were lower than wheat bread (used as control); since bread structure were not able to sustain the CO2 pressure at its best, resulting in a limited volume expansion. The lower leavening performance of barley dough can be explained by the strong impact of barley flour on the leavening properties, mainly attributed to the physicochemical properties of barley b-glucans. In addition, taking into account the total absence of technological improvers and of baker's yeast within the dough formulation, the reduced technological features of barley bread, were quite predictable. However, the aim of this initiative was to get the maximum nutritional benefit from the use of barley in bread-making, trying to improve its performance by using sourdough. Notwithstanding, the recipe was optimized at its best (water content, mixing time, sourdough percentage, fermentation time) until barley bread obtained overall acceptability scores in consumer tests.
Bread is a perishable commodity, whose shelf-life is normally limited by a physicochemical deterioration known as staling. Staling is mainly perceived by the consumer as a hardening of the crumb, a lost of fragrance, and the appearance of a ‘stale flavour’. Although numerous additives and technological adjuncts have been developed to delay staling, this has not been eliminated and remains responsible for huge economic losses to the baking industry and the consumer. As concerns barley bread, the results of our initiative showed an overall acceptability of bread either 5 h after baking or during shelf-life (after 2 and 6 days of storage), thus suggesting that the use of barley flour had apparently no negative influence on consumers' acceptance of barley bread. The use of barley flour and sourdough technology proved to limit economic losses due to bread wastes and contributed to the valorization of barley.
Nowadays, barley bread (with the name of Pandorzo - Recipe covered by National Patent ) is commercialized by La Casa del Pane (Fossombrone); the product is now standardized and very appreciated by the consumers. La Casa del Pane produced a flyer which describes the main traits of the product. La Casa del Pane is now also commercializing a mix containing barley flour and dryed sourdough for home production of barley bread (http://www.barleymix.com/pane-dolci-orzo.htm).
Pandorzo has been presented for the first time during the 7th Edition of Pane Nostrum (Senigallia - AN, 20-23 September 2007); the recipe and the technology for its production have been optimized along the years.
International Publications arised from the initiative aimed to disseminate the results:
M. Mariotti, C. Garofalo, L. Aquilanti, A. Osimani, L. Fongaro, S. Tavoletti, A.S. Hager, F. Clementi. 2014. Barley flour exploitation in sourdough bread-making: a technological, nutritional and sensory evaluation. LWT – Food Science and Technology, 59, 973-980.
A. Osimani, E. Zannini, L. Aquilanti, I. Mannazzu, F. Comitini, F. Clementi. 2009. Lactic acid bacteria and yeasts from wheat sourdoughs of the Marche region. Italian Journal of Food Science, 21 (3), 269-286.
E. Zannini, C. Garofalo, L. Aquilanti, S. Santarelli, G. Silvestri, F. Clementi. 2009. Microbiological and technological characterization of sourdoughs destined for bread-making with barley flour. Food Microbiology, 26, 744-753.
E. Zannini, M. Paoloni, R. Papa, F. Clementi. 2006. Impiego di impasti acidi selezionati per la panificazione con farina di orzo. Tecnica Molitoria, 57(6), 650-658.