Effect of technological processing and maturity stage of seeds on the content and speciation of phosphorus and trace elements in peas

Changes of speciation of phosphorus, manganese, iron, cobalt, nickel, copper, zinc, and molybdenum in pea seeds, occurring as a result of blanching and boiling of green pea, were investigated. Element speciation in green pea was compared with that of mature pea. Speciation analyses were accomplished by size exclusion chromatography – inductively coupled plasma mass spectrometry. Total contents of elements, the respective soluble portions and portions passing a SEC column, were ascertained and mass balances were done. No notable differences between fresh and blanched green peas were found. During boiling of pea, most of the elements were partly leached into water. Excepting nickel and cobalt, the compounds remaining in the boiled peas became less soluble. Soluble high molecular mass element species of zinc, copper, manganese and iron, present in the blanched green peas were markedly diminished by boiling. Low molecular mass species of nickel, cobalt, zinc, and molybdenum were more stable against thermal treatment. The mature pea accumulated higher amounts of elements than did green pea. New soluble high or medium molecular mass fractions of phosphorus, cobalt and copper were formed during ripening of pea seeds. These fractions were not present in green peas. The age of mature peas and the manner of their storage were observed to affect the speciation of copper.