<P>PROBLEM TO BE SOLVED: To provide a method for reducing the sour tastes of vegetables or fruits, by which the sour tastes of the vegetables or fruits can really and effectively be reduced at a low cost without deteriorating the commercial values of the vegetables or fruits. ??<P>SOLUTION: The method reduces the sour tastes of the vegetables or fruits, by irradiating the vegetables or fruits with microwaves having an output power of 200 to 1,500 [W] for 0.5 to 40 seconds. ??<P>COPYRIGHT: (C)2010,JPO&INPIT ??