Molecular Characterization of High β-Glucan Lines in Oats

Abstract: Oats (Avena sativa) are part of the cereal whole grain family, and their production is on the rise for the past few years due to extensive research done on the health benefits it can provide to humans. ScanOats project in Sweden is one of the research groups across the world that has done extensive work on oats. The lines CT-BG-53, CT-BG-21, and CT-BG-37 are mutant lines harvested by Crop Tailor AB and, the type of mutation used with them is chemical mutagenesis using ethyl methyl sulphonate. The mutations were performed on the elite variety of oats called Belinda, and the aforementioned lines were screened by the company as high β-glucan (20-30%) lines. β-glucan is a hydrocolloid polysaccharide that is made up of D-glucose monosaccharides and it can effectively regulate blood sugar and cholesterol levels. The presence of high β-glucan is a commercial advantage for these mutant lines as all the health claims associated with the consumption of oats at this point are associated with the effects of β-glucan. The work conducted in this thesis has made it feasible to further characterise these mutant lines and compare them with Belinda to further elaborate on their superiority. Another important advantage for these mutant lines in comparison to Belinda is the presence of higher total dietary fibre content (20-30 %), which means that the gut will be able to absorb more advantageous dietary fibres. The mutant lines also have higher protein and lipid content in them. The total starch content of all the mutant lines is lower in comparison to Belinda and that could be related to their high dietary fibre content. The viscous behaviour of these lines is similar to that of Belinda which helps defend the fact that the health benefits these lines may provide over Belinda are primarily due to their higher nutritional content and not their physical nature. Arabinoxylan is a non-starch polysaccharide occurring in dietary fibres, and it can give rise to effects like favourable gut microbiome, antioxidant effect and, enhanced immunoregulatory responses. Most of the mutant lines have an arabinoxylan content that is close to Belinda, and it is another valuable feature for them. This arabinoxylan content in these lines also hints toward the fact that the mutation for higher production of β-glucan has not interfered with the pathway to produce arabinoxylan in them. When utilising oats industrially they go through a mandatory heat processing step and through the means of this project it has been discovered these parameters have no negative impact on the amount of the essential nutrients in these lines.