[Problem] To provide a taste improver, when added, in only an extremely small amount, to a food or beverage containing a food material such as tea, coffee, roasted cereal, cacao or fruit, said taste improver being capable of largely enhancing the thickness of the taste, body feeling, etc. of the food material without showing any miscellaneous taste to thereby improve not only the taste balance but also the state of the food or beverage product, and said taste improver being capable of being easily and economically produced. [Solution] A taste improver for a food or beverage that comprises a heat-treated product obtained by adjusting an extract of a starting material of a food material to pH 6-12 and then heating for 10 minutes to 5 hours at 100-180oC, wherein: the starting material of a food material is selected from among optionally processed starting materials selected from the group consisting of tea leaves, coffee beans, roasted cereals, cacao beans and fruits； and the heat-treated product shows a ratio (A/B) of 0.88 or smaller [wherein (A) stands for the OD680 of a diluent of the heat-treated product； and (B) stands for a value corresponding thereto of the heat-treated product before pH adjustment].
