Analysis and thermal stability of porcine thyroglobulin-binding lectins in the major Phaseolus vugaris L. G2/albumin groups

Porcine thyroglobulin (PTG)-binding lectins from cultivars representing the five major G2/albumin groups of Phaseolus vulgaris L. were quantified and assayed for thermal stability with PTG-Sepharose affinity chromatography and the Folin-Ciocalteau protein assay. Lectin concentrations of the five cultivars were 30, 25, 21, 21 and 15 mg g-1 dry flour, for Jamapa (M(G2)), ICA-Pijao (B(G2)), California Light Red Kidney (T(G2)), Black Turtle Soup (V(G2)) and Sanilac (S(G2)), respectively. Heat stabilities of the five major lectin-containing G2/albumin groups were M(G2) = B(G2) V(G2) S(G2) T(G2). Thermally processing whole beans at 89 degrees C for 60-130 min inactivated the lectins in all G2/albumin groups