CHANGES IN CHEMICAL-COMPOSITION DURING DEVELOPMENT OF 3 DIFFERENT TYPES OF PEAS

Three Swedish pea (Pisum sativum L) cultivars, Timo (dark-coloured seed), Vreta (light-coloured seed) and Capella (light-coloured seed and leafless), were harvested at different stages of seed maturity and dehulled by hand. Changes in chemical composition during growth and maturation were analysed in dehulled seeds and dietary fibre components in the hulls (seed coats). Generally, Capella had the largest seeds, the lowest hull content, the highest yield, and the lowest losses due to pod opening. Timo with dark-coloured seeds had the highest hull content. The concentration of sucrose and glucose+fructose was high in the young dehulled seeds and decreased rapidly until the starch concentration reached its maximum early during development. Thereafter, the starch concentration decreased somewhat while the concentration of crude protein and oligosaccharides belonging to the raffinose series increased. Glutamic acid (the predominant amino acid in dehulled seeds), arginine, alanine, threonine and methionine had the highest concentrations in the very young dehulled seeds but decreased rapidly. The concentration of the other amino acids, including cyst(e)ine and lysine, was low in the young seeds and thereafter increased. The concentration of dietary fibre and major dietary fibre components in dehulled seeds generally increased during growth and maturation. Dietary fibre concentration in hulls also increased dramatically during growth and maturation. The light-coloured hulls contained more non-starch polysaccharides, including glucose, uronic acid and xylose residues as major components, but lower concentrations of Klason lignin compared to the dark-coloured hulls.