IN VITRO IRON AVAILABILITY AND ADSORPTION PATTERN ON COMBINATION OF ACIDITY AND LENGTH OF BOILING TIME ON YARD LONG BEAN

The aim of the study is to find iron availability and binding pattern by dietary fiber macromolecule on combination of acidity and length of boiling time, through K ads and K eff , boiling procees at the level of pH 4 and 7 with boiling time at 0 (raw), 5, 15, and 25 minutes. Iron availability and adsorption pattern were analyzed through Miller's in-vitro and Langmuir-Scatchard graph methods. The results of the study showed: (1) the highest iron availability occurs at raw-pH4 treatment; (2) decreasing pH and increasing boiling time decrease K ads ,K eff , percent iron bound, and increase iron availability; (3) iron binding pattern by dietary fiber macromolecules through formation of complex compound was more prominent than physical adsorption, involving two types of specific binding sites, one of which showed a higher affinity. Keywords: iron availability, adsorption pattern, dietary fiber, acidity (pH), boiling time