RESEARCHES ON IMPROVING NUTRITIONAL VALUE OF RYE PRODUCTS

1. RESEARCHES ON IMPROVING NUTRITIONAL VALUE OF RYE PRODUCTS Banu Iuliana, Aprodu Iuliana, Vasilean Ina, Barbu Vasilica, Neagu Corina, Bahrim Gabriela The project Chemical, biochemical and technological researches on improving nutritional value of rye is funded by the CNCSIS that manage the Exploratory Research Projects, PN-II-ID-PCE-2008-2. • Rye (Secale cereale L.) is cultivated around the world, but 95% of the world’s rye is grown in Poland, Germany, western Russia, Belarus and Ukraine. Half of rye harvest is available on EU market. • Rye is an excellent raw material for healthy and tasty foods. • Rye flour can be used alone or in mixtures with wheat to produce bread, but it ismainly used in production of baked specialty products, such as flat breads and rye crisps. Contract no. 1046/2009 Acronim NutriRye Research team: Experienced researchers: Banu I., Bahrim G., Barbu V. Early stage researchers: Neagu C., Vasilean I. TASK I. Biochemical and technological characterization of the rye and rye flour http://www.nutrirye.ugal.ro • Started in January 2009; • Focused on developing functional foods based on cereals, in agreement with the EU demand, in the research field of cereal (EU/ICC Cereal Conference, 2002); • The major objective of NUTRIRYE project consisted in finding the ways of better using the biologically active compound from raw materials through newly develop processing technologies. • Rye, whole and dark rye flours were used in the research. • The correlations among grain rye quality factors: proximate structural and compositional particularities, endosperm matrix protein, and milling performance were evaluated. • Based on the fact that the knowledge of the rheological properties of the flour is essential for establishing the baking parameters, we used the Mixolab device to measure dough’s torque associated to mixing and temperature constraints. TASK IV. Ability of LAB strains to produce homoexopolysaccharides (HoPS) • All LAB strains investigated, except for 15GAL+16GAL, formed considerable amounts of HoPS during rye sourdough fermentation. • The monosaccharides were identified by high-performance liquid chromatography (HPLC) using an Altima Amino 100Å column and refractive-index detector. • The levels of HoPS ranged between 0.88 and 1.75 mg/g of whole rye flour. TASK II. Cultivation, isolation and identification of different LAB strains • Identification of the LAB strains isolated from rye microbiota was made with API 50CH kit and with API 20 STREP kit (BioMerieux). • Weissella confusa (UGAL1) • Lactococcus lactis ssp lactis (UGAL2) TASK III. Sourdough preparation. Analysis of metabolites. Rye bread quality TASK V. Evolution of the bioactive compounds during the whole process of making the sourdough rye bread • Sourdough preparation • Whole rye flour: 1.9% ash content (308 s falling number value) • Dark rye flour: 1.3% ash content (346 s falling number value) • Dough yield (DY, mass of dough/mass of four x 100) of 150, 200 and 300 • Incubation at 30°C and 37°C for 20 h • LAB: UGAL1, UGAL2, 15GAL and 16GAL (MIUG collection), DIPROX-MTTX (EDR), LH-B02 and LAF-4 (Christian Hansen) • Size of LAB inoculum: 3-5 x 108 ufc/100 g dough • The total phenolic content and antioxidant activities assessed using Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity expressed in terms of Trolox equivalents and of percentage of discoloration, were measured; the folic acid content was measured using ELISA method. • The results indicated that the phenolic content, antioxidant capacity and folic acid content of the rye can be modulated during the bread making process. • The type of fermentation and the metabolic activity of LAB influence the levels of bioactive compounds that enable the increase of the phenolic content and antioxidant capacity of the sourdough, dough and rye bread. Rheological measurements of the sourdough • Controlled-stress rheometer attached with computer control software TASK VI. Rye flour processing technology based on the use of sourdough • Technology has been registered at State Office for Inventions and Trademarks of Romania (A201100209/10.03.2011; BOPI no. 9/2011). • Analysis of major metabolic end products • D, L-lactic acid • Acetic acid • Ethanol • Glycerol TASK VII. Disemination • Research articles • Food Biotechnology, 25(4), 2011 • Italian Journal of Food Science, 22(1), 2010 • Food Science and Technology Research, 16(6), 2010 • Scientific Study & Research, Chemistry & Chemical Engineering, Biotechnology, Food Industry, 10(3), 2009; 12(2), 2011 • Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture, 67(2), 2010 • Rye bread quality • Bread volume, pH and TTA • Porosity of the bread – Image J software • Crumb firmness during storage – texture profile analysis test • Sensory profiles of the bread – descriptive analysis • Book • Lactic Acid Bacteria – Breadmaking Applications, 2010 • International Conferences • Colloque Franco – Roumain de Chimie Appliquee,Orleans, France,2010 DY 300, 20 h/30°C DY 300, 20 h/37°C DY 150, 20 h/37°C DY 150, 20 h/30°C http://www.nutrirye.ugal.ro