Abstract
Oat mixed-linkage β-glucan has been shown to lower fasting blood cholesterol concentrations due notably to an increase in digesta viscosity in the proximal gut. To exert its action, the polysaccharide has to be released from the food matrix and hydrated. The dissolution kinetics of β-glucan from three oat materials, varying in their structure, composition and degree of processing, was investigated by incubating the oats at 37°C over multiple time points (up to 72h). The samples were analysed for β-glucan content, weight-average molecular weight and rheological behaviour. Regardless of the materials studied and the processing applied, the solubilisation of β-glucan was not complete. Mechanical and hydrothermal processing led to differences in the viscosity flow curves of the recovered solutions, with the presence of particulates having a marked effect. This study revealed that the structure and processing methods applied to oat materials resulted in varied and complex rheological properties, especially when particulates are present.
Highlights
The common oat grain (Avena sativa L.) is consumed by humans mainly as breakfast cereals, comprising whole grain flour or flakes, which can be eaten either as porridge after heating in water/milk or in the form of ready-to-eat cereals, such as muesli and granola (Webster, 2011)
The purpose of the current study was to investigate the effects of differences in structure and particle size of selected oat flours and flakes on the dissolution kinetics and solution rheology of glucan during aqueous incubation
The novel incubation assay presented in the current work has provided a simple and reproducible method to evaluate the effects of mechanical and hydrothermal processing of oats on oat -glucan solubility and subsequent solution viscosity
Summary
The common oat grain (Avena sativa L.) is consumed by humans mainly as breakfast cereals, comprising whole grain flour or flakes, which can be eaten either as porridge after heating in water/milk or in the form of ready-to-eat cereals, such as muesli and granola (Webster, 2011). The -glucan content of oat varies depending on genotype and environmental conditions during growth and ranges from ∼2.2 to 7.8% (Lazaridou, Biliaderis, & Izydorczyk, 2007) It is a polydisperse polysaccharide with reported values of average molecular weight (MW) between ∼0.1 and 2.5 million g/mol (Åman, Rimsten, & Andersson, 2004; Andersson & Börjesdotter, 2011; Beer, Wood, & Weisz, 1997; Doublier & Wood, 1995; Johansson, Virkki, Maunu, Lehto, Ekholm, & Varo, 2000). Manipulating the MW of -glucan and the particle size of oat particles led to materials with different solubility and viscosity (Wang & Ellis, 2014)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
