Dietary fiber content and composition in heritage wheat

Abstract: Wheat is the main food source in the world. A secured production has however been threatened by environmental changes in combination with the need of producing more food for a growing population. As a result, there has been an increasing interest in finding new crop varieties susceptible to abiotic stress. A growing concern has also been seen among consumers regarding sustainability, local markets and health which has led to an increased interest in heritage cereals due to their claimed health benefits, nutritiousness and better resistance against abiotic stress. Though, these claims lack a proper foundation and more research is needed before any statements can be claimed. The present study aimed to analyze the dietary fiber content and composition of heritage wheat and investigate if potentially differences may be a result of wheat population (genetic background), cultivation location or treatment. Three heritage wheat populations (Dala Lantvete, Ölandsvete and Källunda) and one modern variety (Dacke) were cultivated at two locations in Sweden, within two blocks and with two treatments (with or without fertilizer) in each block. The samples were evaluated regarding dietary fiber content and composition, including arabinoxylan and fructan, which are the two most abundant dietary fibers in wheat. Principal component analysis (PCA) was used for multivariate analysis of the data set, followed with two-way analysis of variance (ANOVA) to find possible differences between samples. In the PCA the wheat populations were separated in different clusters along PC 2, and fructan was the variable that contributed mostly to this separation. The ANOVA showed that the total dietary content, as well as arabinoxylan content, was mostly influenced by wheat population. Slightly lower contents were found in the heritage wheat populations than in the modern Dacke, with the lowest content in Ölandsvete. Fructan content can both be influenced by genetic background, and be an indication of a stressed plant and was found in the highest content in the modern variety Dacke. However, the differences between the samples were rather small and more research is needed before any general conclusion can be drawn.