Plant cell walls and cell-wall polysaccharides: structures, properties and uses in food products

We describe preparations of plant cell walls and polysaccharides obtained from plant cell walls that are added to food products for two purposes: as modifiers of food texture and/or as dietary fibres with potential health benefits. Although a number of different types of plant cell walls occur, only some are presently exploited. Commercial 'fibre preparations' range from those containing mostly primary walls to those containing mostly lignified secondary walls from which much of the lignin and non-cellulosic polysaccharides have been removed. Preparations of cell-wall polysaccharides are obtained from the following sources: cellulose mostly from secondary walls of cotton and wood, pectin from primary walls of dicotyledons, and (1 -> 3),(1 -> 4)-beta-glucans and arabinoxylans from primary walls of cereal grains. Preparations of galactomannans, xyloglucans and the pectic polysaccharide rhamnogalacturonan I are obtained from non-lignified secondary walls of certain leguminous seeds. The compositions, functionalities, uses and possible health benefits of these different preparations are discussed.