AbstractThe purpose of this study was to see how inoculum loading (2 and 5% v/v) and fermentation period (0–72 h) affected the functional properties ofA. paeoniifolius(Dennst.) Nicolson yam flour.L. plantarumfermentation was used to ferment the sliced yam. In general, swelling power of modified flour increased along with the increasing of inoculum and fermentation time but not significant, while the water solubility index reduced significantly by fermentation. The water absorption capacity of flour increased significantly as inoculum concentration and fermentation period were increased, and then decreased with the length of the fermentation process. Bulk density implied that the fermentation process formed an open structure of starch granule with a higher proportion of void spaces. The FTIR analysis showed the modification of functional groups of starch that indicates the change of physicochemical properties along the fermentation process due to the interaction ofL. plantarum. The color of the treated flour whiter than control makes its application for various food products will be wider. This result suggested that fermentation by 5%L. plantarumwithin 48 h could provide a greater extent of flour such as processed cheese, sausage, dough, and baked products.