Chemical characterization of BG oxidation products

Project abstract

Beta-glucan is the only dietary fibre compound that is allowed health claims for its capability to maintain healthy cholesterol levels. Until very recently degradation has been considered detrimental to the health effects of beta-glucan, but on the other hand, beta-glucan oxidation has not been recognized to occur in food systems. However, in the past few years beta-glucan oxidation products have been demonstrated to have improved health-promoting properties and beta-glucan oxidation has been demonstrated to occur also in regular food processing. This has brought about the need to understand the oxidative reactions of beta-glucan and the necessity to chemically characterize the resulting oxidation products.

This project aims to develop a highly sensitive method to analyze the nature of the beta-glucan oxidation products by ultra-high performance liquid chromatographic methods using high resolution mass spectrometric detection (UPLC-q-TOF). As a further dimension, the aim is also to study the positional features of the oxidation products (with ion mobility technique that separates ions with equal mass based on their shape) and to demonstrate the locations in the polymer that are most prone to oxidation. Within the frame of this project the aim is to apply the method to characterize oxidation products from hydroxyl radical mediated oxidation in both purified beta-glucan solutions and in beta-glucan extracts, but further applications include the studies of oxidation products also in foods. The chromatographic-mass spectrometric method developed here is complemented with other analytical techniques (rheology, FT-IR spectroscopy, size-exclusion chromatography, titrimetry etc) and this comprehensive toolbox can be used to very specifically characterize beta-glucan oxidation products from various food systems, and to assess the molecular interactions of the oxidation products with other components in foods and in the digestive tract. The proposed project will then bring light to the mechanisms of beta-glucan action and tools for developing functional beta-glucan enriched foods.