A large number of studies have been made on the method for preserving, and controlling the release of, a flavor (“Latest food flavor technology”, published by INDUSTRIAL TECHNOLOGY SOCIETY, 1988), and microencapsulation, enclosure in matrix, inclusion with a cyclodextrin or equivalent, as well as reaction of an enzyme upon a volatile component precursor such as a glycoside.
It is difficult, however, to control the release level as desired in a physical preserving method, and in a method employing a glycoside, the target compounds are limited to terpene alcohols and the enzyme may be inactivated when used in a heated system, these being some examples of the problems associated with the prior art.
On the other hand, mercapto group-containing compounds generally have a low flavor threshold, and frequently play an important role in the flavor characteristics of products such as fragrances and foods. For example, mercapto compounds which are furan derivatives are known as contributing greatly to the food flavor of a product such as coffee or meat. Nevertheless, since such mercapto compounds involve difficulties in controlling the flavor release level within an appropriate range because of their low flavor threshold and also in preserving the concentration thereof within a certain range for a prolonged period, a method for preserving and releasing their flavor efficiently have been demanded to be developed.