PROBLEM TO BE SOLVED: To provide a quality improver that improves and enhances the quality of vanilla extract after production thereof, in order to provide a good quality vanilla extract without a need to depend on the preparation method, as the production of natural vanilla involves curing and drying steps followed by maturing for 6 to 12 months and whereas steps thereof are under a great constraint of weather and air temperature or the like and on top of it the risk of the microbial contamination is also high and therefore it has been very difficult to stably maintain the quality of vanilla and thus a good quality natural vanilla has been very rare.SOLUTION: A vanilla extract quality improver characterized in comprising trans-2-nonenal is added to a vanilla extract by 0.001 ppb to 100 ppm, thereby the quality of a vanilla extract having a quite natural and luxury feeling as well as a good-quality flavoring can be ensured.
