Protein extraction from lupin seeds: microstructural aspects and hypothesis of mechanism

Summary Protein was extracted into water (pH 8.0, 1 h) from defatted lupin seed kernel particles (mean θ, 1425 μm). Intact and extracted particles were examined by scanning and transmission electron microscopy. The inner surface of the cell wall initially showed several small holes considered as possible sites of plasmodesmata. During extraction, protein bodies first became disrupted into smaller microstructures and then protein dissolved. Wide passages were formed between cells which allowed transport of protein. The molecular weight of proteins in solution did not change with time, suggesting that bulk flow rather than selective transport predominated.