Enhancement of physicochemical properties of sugar beet fibres affected by chemical modification and vacuum drying

Abstract

The effects of chemical modification with hydrogen peroxide and different temperatures of vacuum drying (55, 65 and 75°C) on content of soluble and insoluble dietary fibres, physicochemical properties (colour, structure, water binding and swelling capacity) and drying kinetics of sugar beet fibres were studied. An increase in soluble and insoluble fibre ratio for 20–40% and fibre brightness for approximately 25% was achieved by chemical modification compared to the non-modified fibres. Further, swelling and water binding capacities of fibres, after conducting chemical modification, were three to four times higher than for non-modified fibres. Uniform reduction of a drying time with a rising temperature and fluctuating drying rate decrease were observed in modified fibres samples. The mentioned effects are explained by changes in fibre structure upon chemical modification. The whole study indicates that chemical modification and vacuum drying are suitable for sugar beet fibres and that modified fibres can be used as additives in food industry in order to fortify the diet.