Conference lecture and academic presentation » Academic lecture
Effect of growth temperature on starch quality and fibre content in barley
6th European Young Cereal Scientist and Technologist Workshop; Montpellier, France, 2007-04-30–2007-05-02
Barley contributes to the world’s food supply as animal feed, malt products and human food. Eight different 2-row barley (Hordeum vulgare) cultivars were grown in controlled environmental chambers at 9?C, 12?C, 15?C, 18?C and 21?C from anthesis to maturation. After harvesting the grains were pearled and milled. The results show that the growth temperature does not affect the ratio between amylose and amylopectin in barley. The content of lipid complexed amylose (LAM) is affected by the temperature, but the cultivars responded differently. The starch degradation was measured using an in vitro model simulating the digestive tracts of monogastrics. The starch degradation is negatively correlated with growth temperature, and it is strongly affected by the amylose content. The starch granule size distribution curves showed that grains grown at higher temperature have smaller starch granules, and that the cultivars respond differently. The content of total ?-glucans was not affected by the growth temperature, but the ratio between water soluble and insoluble ?-glucans was: There was more of the soluble ?-glucans with increasing temperature. Extractions and purifications have been made (at 37?C) of the water extractable ?-glucans to investigate if the growth temperature has an effect on the viscosity and the molecular weight of the ?-glucans. Preliminary results may indicate that both viscosity and molecular weight are positively correlated with the growth temperature, indicating that not only the total amount, but also the quality of the ?-glucans may have an impact on the end use of the barley grains.