We investigated the interaction effects of four gum-hydrates and reheating treatment on qualities of low-fat Kung-wan, an emulsified meatball. A four-factor rotatable central composite design was adopted for this study on konjac premixed with Ca(OH)(2) (Konjac/Ca(OH)(2)), agar, curdlan gum and kappa-carrageenan. Results indicated that there was no significant interaction among the four gums in the testing ranges for the testing quality indices except for Konjac/Ca(OH)(2) and curdlan gum. Adding about the same amounts of Konjac/Ca(OH)(2) and curdlan gum to the products at the same time yielded higher chewiness and gumminess. Konjac/ Ca(OH)(2) and kappa-carrageenan increased cooking yield. Reheating had significant softening effects on product qualities, but its interactions with the gum-hydrates were insignificant except for Konjac/Ca(OH)(2), which increased the brittleness of the heated products. Curdlan gum also increased product adhesiveness and viscosity. kappa-Carrageenan decreased product viscosity. The inferior taste of Konjac/Ca(OH)(2) was improved when the products were reheated. (C) 2000 Elsevier Science Ltd. All rights reserved.