behaviour model are used in screening program in former model plant extract or enriched fraction is applied on the tongue of anaesthetized gerbil and electrophysiological response record from chorda typhani nerve in this assay about25samples can be investicated in individual animal this study is further supplemented by conditioned taste dislike assay using gerbils that are trained to avoid sucrouse althoug combination of these two models is not ideal for evaluation of human sweet taste about60-70% of pure compound tested in gerbil respond correctly