Abstract
Australia is the 5th largest exporter of wheat in the world. Among other breeding aims,maintenance and improvement in grain quality is an important goal of Australian wheat industry. The objective of this study is to investigate the changes in the quality of Australian wheat varieties over the last century. A set of 78 varieties released between 1860 and 2015 were selected and studied in terms of physical grain attributes, milling quality, dough rheology and protein composition. Protein composition (gliadin and glutenin content and composition) was examined using high performance liquid chromatography (HPLC) while dough rheological characteristics were investigated by Mixograph, Micro-doughLAB and Extensograph tests. Grain protein contents were observed to be decreased in modern varieties although not when considered as grain protein accumulation per hectare and this is explained by the negative correlation to increase in grain yield. Over the years, significant changes in quality parameters of varieties have been found. Compared to historical varieties, modern cultivars were found to be stronger as observed by micro-doughlab and mixograph results
(increase in dough development time, dough stability, peak mixing time, midline peak width and decrease in softening after 5 min of mixing and weakening slope). The improvement in protein quality, compensating the decrease in protein content, is associated with the increase in glutenin to gliadins ratio and un-extractable polymeric proteins (UPP%). The shift in the size distribution of polymeric proteins is derived from the systematic alteration of higher molecular weight (HMW) and lower molecular weight (LMW) glutenin alleles in the modern cultivars. The two most significant examples in this alteration are the increase in the number of cultivars containing the Glu1Dd and Glu1Bal alleles (HMW glutenin subunits 5+10 and overexpressed 7 respectively) and also the consideration of the effects of LMW glutenin alleles determining functional properties. Selection within the diversity of glutenin and gliadin composition of Australian wheat varieties has led the breeders to the development of wheat varieties with improved dough functionality and better product quality in more recent years. The current research provides evidence that by selection, wheat breeders have changed the protein composition of current varieties and this has led to an improvement in grain quality. This selection will need to continue to meet the demands of industrial bread-making processes.
(increase in dough development time, dough stability, peak mixing time, midline peak width and decrease in softening after 5 min of mixing and weakening slope). The improvement in protein quality, compensating the decrease in protein content, is associated with the increase in glutenin to gliadins ratio and un-extractable polymeric proteins (UPP%). The shift in the size distribution of polymeric proteins is derived from the systematic alteration of higher molecular weight (HMW) and lower molecular weight (LMW) glutenin alleles in the modern cultivars. The two most significant examples in this alteration are the increase in the number of cultivars containing the Glu1Dd and Glu1Bal alleles (HMW glutenin subunits 5+10 and overexpressed 7 respectively) and also the consideration of the effects of LMW glutenin alleles determining functional properties. Selection within the diversity of glutenin and gliadin composition of Australian wheat varieties has led the breeders to the development of wheat varieties with improved dough functionality and better product quality in more recent years. The current research provides evidence that by selection, wheat breeders have changed the protein composition of current varieties and this has led to an improvement in grain quality. This selection will need to continue to meet the demands of industrial bread-making processes.
| Original language | English |
|---|---|
| Pages | 21-23 |
| Number of pages | 2 |
| Publication status | Published - Oct 2019 |
| Event | Cereals and Grains 2018: AACCI2018 - Hilton London Metropole , London, United Kingdom Duration: 21 Oct 2018 → 23 Oct 2018 https://www.aaccnet.org/meetings/archive/2018/about/Pages/default.aspx https://www.cerealsgrains.org/publications/plexus/cfw/pastissues/2018/nov-dec/Documents/CFW-63-6-0281.pdf (Abstracts) |
Conference
| Conference | Cereals and Grains 2018 |
|---|---|
| Country/Territory | United Kingdom |
| City | London |
| Period | 21/10/18 → 23/10/18 |
| Other | Cereals & Grains 18 is the place to learn, collaborate, and innovate with the best and the brightest in the grain-based foods industry! This targeted event draws a world-wide audience from industry, academia, and government each year. |
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