COMPOSITION, PROPERTIES, AND NUTRITIVE-VALUE OF DIETARY FIBER OF LEGUME SEEDS - A REVIEW

Non-starch polysaccharides (NSP) and lignin are the principal componen ts of dietary fibre. Legume seeds such as faba beans, peas, and lupins contain considerable amounts of non-starch polysaccharides. The avera ge NSP content is 177 g in faba beans, 185 g in peas, and from 320 to 400 g/kg DM in different lupin species. Seeds of Lupinus angustifolius contain more NSP than seeds of Lupinus luteus and Lupinus albus. Diff erences among lupin species in the NSP level result from differences i n the content of NSP sugar residues, particularly rhamnose, xylose, ga lactose, and uronic acids. Glucose and galactose constitute the main p art of NSP sugar residues in lupin seeds. NSP of pea seeds and faba be ans are mainly composed of glucose, arabinose and uronic acids. Dietar y fibre of legume seeds may also include other components such as a-ga lactosides, resistant starch, polyphenols, and protein bound to cell w alls. Different proportions of carbohydrates either hydrolysed by endo genous enzymes or fermented by gut microflora and of fat result in a d ifferent energy value of the legume seeds for animals. Since bacterial fermentation of NSP is more intense in the hind-gut of pigs, legume s eeds have a higher energy value for these animals than for poultry. A high NSP content in animal diets negatively affects digestibility and nutrient absorption, while it may have beneficial dietary effects on h umans. Different treatments, i.e. dehulling, microbial enzyme suppleme ntation, are used to improve the nutritional value of legume seeds for monogastric animals.