In vitro protein digestibility in grain sorghum: effect of genotype and interaction with starch digestibility
- PDF / 415,646 Bytes
- 11 Pages / 547.087 x 737.008 pts Page_size
- 24 Downloads / 187 Views
In vitro protein digestibility in grain sorghum: effect of genotype and interaction with starch digestibility L. A. Elkonin • J. V. Italianskaya • I. Yu. Fadeeva • V. V. Bychkova • V. V. Kozhemyakin
Received: 24 December 2012 / Accepted: 30 March 2013 Ó Springer Science+Business Media Dordrecht 2013
Abstract Improvement of nutritive value is one of the main goals of sorghum breeding. It is known that one of the reasons of relatively poor nutritive value of sorghum grain is resistance of its seed storage proteins (kafirins) to protease digestion that also affects digestibility of starch. To study genetic aspects and interdependency of these traits we investigated in vitro protein and starch digestibility of the flour of 12 grain sorghum lines and six F1 hybrids. Comparison of SDSPAGE spectra of total grain proteins before and after pepsin digestion revealed that the F1 hybrids had significantly lower indices of protein digestibility than parental lines, with the exception of the F1 hybrid M35-1A KB/KVV-45, which retained high level of protein digestibility typical for KVV-45 line. The level of starch digestibility in the F1 hybrids corresponded to its level in maternal lines suggesting importance of maternal genotype in determination of this trait. It was found that starch digestion by amylolytic enzymes increased the amount of protein in individual kafirin fractions, and reduced the amount of high molecular
L. A. Elkonin (&) J. V. Italianskaya I. Yu. Fadeeva V. V. Kozhemyakin Dept. Biotechnology, Agricultural Research Institute for South-East Region, Tulaikov Street, 7, Saratov 410010, Russia e-mail: [email protected] V. V. Bychkova All-Russian Research Institute for Sorghum and Maize ‘‘Rossorgo’’, Saratov 410050, Russia
weight proteins as well it reduced subsequent kafirin digestion by pepsin and caused formation of polypeptide (Mr *45 kDa), perhaps, the kafirin dimer, resistant to pepsin digestion. These data are of importance for fundamental investigation of factors influencing kafirins and starch interactions in sorghum endosperm and their digestibility. Keywords Kafirins In vitro protein digestibility In vitro starch digestibility Sorghum bicolor (L.) Moench
Introduction Climate aridization that is distinctly observed in many regions all over the globe, hampers sustainable production of traditional cereals, such as wheat, maize and barley, and dictates necessity to grow drought resistant and heat tolerant crops. Among these crops the grain sorghum takes one of the leading places owing to its ability for sustainable grain production in conditions of minimal level of precipitation. However, application of sorghum for food and feed purposes is limited by relatively poor nutritive value of sorghum grain in comparison with other cereals. One of the reasons of relatively low nutritive value of sorghum grain is resistance of its seed storage proteins (kafirins) to protease digestion (Oria et al. 1995). The causes of the poor sorghum protein digestibility were studied extensively (reviews: Belton
12
Data Loading...
