WHAT DO ANISE , STAR ANISE, AND FENNEL HAVE IN COMMON ?

Anethole is the chemical constituent in the essential oil of the fruits of anise, star anise, and fennel. Essential oils are responsible for the flavor and aroma of spices. When extracted from the appropriate plant part, they are used as substitutes for the original plant to flavor food and scent a wide variety of products.

The oil of quality anise seed is 80 percent to 90 percent anethole, that of fennel is 50 percent to 60 percent anethole, and star anise oil is 85 percent to 90 percent anethole. All three oils contain a number of other constituents which account for the difference in flavor among the three, but the large amount of anethole gives them a great degree of similary in flavor.

In its natural state, anethole is a white crystalline substance with an intensely sweet anise-like odor and flavor. Anethole "melts" to a liquid state at relatively low temperatures, around 20 to 22 degrees Celsius (68 to 72 F). This liquid anethole, when exposed for long periods to light, heat, or air, slowly loses its ability to crystallize and undergoes undesirable flavor changes.

When stored below 15 degrees Celsius (59 F), quality anise and star anise develop a glitter-like appearance. This effect is caused by the anethole crystallizing on the outside of the fruits. This does not occur in fennel because of its lower anethole content. As the fruits warm, the anethole "melts" and the glitter effect disappears. Repeated warming and cooling decreases the anethole content and thus lowers the quality.

To help maintain the quality of spices, proper storage is always important. Cool, dry, storage conditions with minimum exposure to light and air are the standard requirements for every spice. Anise, fennel, and star anise benefic from proper storage by maintaining their anethole content and thus their distinctive flavor and aroma.