Sensory interaction of umami substances with model food matrices and its hedonic effect

Palatability changes in seven model foods (soups and mashed potato) evoked by various combinations of monosodium glutamate (MSG) and disodium inosinate and guanylate (I + G) were studied. Flavour enhancers were added to each food matrix according to the same factorial design. The magnitude, direction and regularity of hedonic responses were highly product-dependent. Contribution of MSG and I + G to palatability-enhancement also varied for different model product: in chicken broth and vegetable soup MSG played the leading role; in mushroom, red beets and asparagus soups contribution of I + G was considerable. In green peas cream soup the supplementation by MSG/I + G evoked mostly negative hedonic effect. Analysis of naturally present free amino acids revealed considerable differences in their amount and composition. The interaction of naturally present glutamates and added umami substances (and probably other sensory-active compounds) might be at least partially responsible for observed diversity of hedonic responses.